Changes in v6.6.5.0 - 06/09/2020
1 Added alternate dialog input method for Elements. A separate Add button (+) has been added to the Toolbars for adding elements to a member. Instead of simply adding a new line to the Data Grid, this will present 3 Dialogs for
- Locations data
- Cross-Section Shape
- Number of and transverse location and spacing of shapes.
The same dialogs are available on selecting Graphical Input from the Toolbar for an existing element data row if the data is not already available in the Data grid.
2 Modified the Input Options for earthquake design in Design Data - Earthquake design. Previously there were options for minimum area of reinforcement in various zones and minimum capacity in various zones depending on the member type.
The minimum area logic is not consistent with prestress design, so we have modified it to minimum capacity only in this screen for all member types. Reinforcement - General still has options to set minimum continuous reinforcement in the top and bottom as well. These are automatically turned on when Earthquake Design is selected.
The options now are
- Minimum Reverse Face Capacity at Support Hinge
- Minimum Support Face Capacity as a fraction of Support Hinge Capacity
- Minimum Span Face Capacity as a fraction of Maximum Support Hinge Capacities
- Minimum Span Face Capacity as a fraction of Maximum Span Face Capacity
- Multiplying Factor for Minimum Reinforcement Calculation
- Concrete Shear Capacity within 2D of support
- Neutral Axis Ductility Limit for Earthquake Sway Plastic Hinges.
This Ductility Limit will apply only at support hinges and will over-ride the general limit in Design Data - General at these locations. RAPT does not use the reinforcement ratio to control ductility as is required by some design codes. For any design code that nominates this limit in terms of a reinforcement ratio limit, the designer will have to convert that to an equivalent neutral axis depth limit in this data field or a strain limit in the data field below this.
- Strain Ductility Limit for Earthquake Sway Plastic Hinges
- Shear Capacity based on. Options are Applied Shear or Capacity Shear. If Capacity Shear is selected, the next 2 data fields are available to define the required data.
- Section Capacity Multiplier for Capacity Shear.
- Earthquake Load Multiplier for Capacity Shear.
The online Help has been modified to explain these options.
The Defaults data for Earthquake Design for different Design Standards has been modified to reflect these changes and allow the setting of appropriate default values. The Code defaults supplied with RAPT will automatically give our default values for these options.
In the General Data Screen, the Earthquake Design options are
- None - which equates to Ordinary Moment Frames where special detailing is not required.
- Moderate Risk - which equates to Intermediate Moment Frames which are Moderately Ductile and require some special detailing.
- High Risk - which equates to Special Moment Frames which are Fully Ductile and which require the use of ductile (Aus/NZ Class E or equivalent) reinforcement along with a higher level of detailing again.
or the equivalent ductility classes in different design codes.
3 For Earthquake Load Combinations in the Output, There are now combinations provided for
- Earthquake Defined - Flexure and Shear. These use the Earthquake Combinations as defined in input but using the Earthquake Load Multiplier for Capacity Shear defined in Design Data - earthquake and provide Moment controlled and Shear Controlled envelopes.
- Capacity Shear - Felxure and Shear. These use the Earthquake Combinations as defined with the Earthquake Load E set to 0. The negative and positive section capacities at the support centrelines are then used to create Capacity Controlled Shear diagrams. Both sets of these are Shear Controlled Envelopes for different combinations of +ve and -ve section capacity at the support critical sections.
Many design codes then require the lesser of the earthquake Defined and Capacity Shear values to be designed for at each design location. RAPT will do this automatically if the Earthquake Load Multiplier for Capacity Shear is set to a value > 1.0. If it is set to 1.0, RAPT will design for both Earthquake Desined and capacity Shear values (e.g. Eurocode).
Earthquake Load effects are still included in the Ultimate Design - Flexure and Ultimate Design - Shear Combinations as defined in the Input Load Combinations so that they are included in the flexural design calculations.
4 Shear design and detailing is now done for the Ultimate Flexure and Ultimate Shear combinations using normal shear detailing rules. It is then also done for the Earthquake Defined and Earthquake Capacity combinations as discussed above with earthquake detailing requirements. The case requiring the smallest stirrup spacings out of all of these checks is then adopted as the reported result.
5 The AS3600-2018 release of RAPT did not use the requirements of clause 8.2.1.6 to determine the design shear at which minimum shear reinforcement is required to be added as we felt this was too unconservative. RAPT continued to use the 2009 code rule for this. This clause has now been modified in Amendment 2 to AS3600 which is currently available as a Draft for Public Comment. RAPT now includes the much more sensible provisions in the new Amendment document rather than the 2009 code rules for the AS3600-2018 implementation.
6 Column Design - Text output is now provided for the nominated design points detailing the values for the Intersection Points on the interaction diagram for each nominated (M*, N*) Design Point. Previously Intersection Points were only provided on screen on the graphics using the Toolbar icon for a user defined point that was not recorded for output. Values are given at the
- Axial Force Intersection Point - Axial Force phi Nu at intersection of vertical line through defined point and interaction diagram with co-existing M*
- Diagonal Intersection Point - Moment and Axial Force - Phi Mu, Phi Nu point
- Moment Intersection Point - Moment Phi Mu at intersection of horizontal line through defined point and interaction diagram with co-existing N*
- Second Axial Force Intersection Point in case of Tension Columns - Axial Force Phi Nu at second intersection of vertical line through defined point and interaction diagram with co-existing M*
Changes in v6.6.4.0 - 19/01/2020
1 Fixed intermittent crash in determining longitudinal reinforcing bar requirements for shear.
2 Fixed intermittent crash in graphics generation with metal decking voids already created and subsequent section depth modification makes the void shape illegal (outside section).
3 Fixed error in generating tendon profiles in case where a sloping straight tendon in one span connects to a reverse curve for a parabolic profile in the joining span.
4 Column Interaction Diagraams Tension calculations. The phi calculation for AS3600 was using a fixed basic value of phi = .8 in the formula for the calculation of phi for tension zones in interaction diagrams, rather then the defined value in the Design Data. With the change to .85 in AS3600-2018, this formula was still using .8 as the starting value. This has been changed to use the value in the Design Defaults.
A Note for AS3600-2018 designers using RAPT for column interaction diagrams. AS3600 Table 2.2.2(d) has a starting value of phi for compression, phi0, which can be either .6 or .65 depending on the column slenderness and ratio of Q/G. Short Columns with Q/G >= .25 use .65. All other columns use .6.
RAPT's default value is .65. In generating a general interaction diagram, RAPT does not check slenderness and makes no attempt to determine which value should be used. The determination of a column status as Short is also dependent on the column loading which RAPT does not know. The RAPT user will have to manually modify the value of phi for compression in the Design Data depending on the situation with each interaction diagram being created.
Changes in v6.6.3.0 - 17/11/2019
1 Fixed problem in crack control where sometimes RAPT accepts a bar size greater than the maximum allowed.
2 Modified crack control calculations in cases where the maximum bar spacing allowed for crack control is smaller than the minimum bar spacing allowed for constructability. RAPT adds tension reinforcement to reduce the stress change in the reinforcing bars until the maximum bar spacing allowed is greater than the minimum allowed spacing. The resulting bar spacing may still be too small for practical use. In this case, the designer can adjust the Stress Change Limit in Design Data - Crack Control to a value that will allow a maximum bar spacing that they are willing to accept.
3 For AS3600 Prestressed Section crack control, where the crack control is achieved by limiting bar size only, modified crack control calculations in cases where the maximum bar diameter allowed for crack control shows as 0 due to the value of the stress change being outside the AS3600 code limits. RAPT adds tension reinforcement to redcue the the stress change in the reinforcing bars until its value is within the tabulated values. The resulting bar size may still be too small for practical use. In this case, the designer can adjust the Stress Change Limit in Design Data - Crack Control to a value that will allow a maximum bar size that they are willing to accept.
4 Corrected headers for graphics in Flexure - Characteristic and Permanent Reports.
5 Column Module - Reinforcement Input, fixed crash where select tool used to select a group of bars and then select Modify to change bar diameters.
6 Fixed loads input graphics in cases where point loads are showing over the top of Panel Loads.
7 Fixed incorrect removal of loads when Left and Right Cantilevers delected (converted to LeftEnd and Right End).
Changes in v6.6.2.0 - 12/09/2019
1 Fixed auto recalculation of Column Slenderness when Rotation changes. Designers had to force the recalculation using the Recalculation Toolbar Icon previously. Slenderness is only calculated for the 1st rotation defined at the moment.
2 The plastic centroid and effective depth values were not being remembered for each separate Rotation since the option for multiple rotations was added. The last calculated was remembered and reported for all rotations. This has been fixed.
Changes in v6.6.1.0 - 18/08/2019
1 Fixed problem in Asv/s calulation for AS3600-2018 for sections requiring more than minimum shear reinforcement. For only this calculation, RAPT was using d rather than dv
2 Fixed data check for reinforcing bar spacing in input with varying width sections.
Changes in v6.6.0.0 - 23/07/2019
1 Added design rules for AS3600-2018
- phi factors modified (Default Design Code file modified)
- Concrete shrinkage data modified (Default Materials file modified). The Shrinkage equations were modified several years ago to fix the problems in AS3600-2009 for shear for concrete strengths above 50MPa that heave been fixed in AS3600-2018.
- AS3600 ductility calculations modified to use do and kuo rather than d and ku for ductility calculations. The result is that ductility is now based on a limiting strain calculated from .67 of the balanced condition when there is only one layer of tension reinforcement at the tension face. So, for other cases where the effective depth is significantly lower than do, the .67 * balanced condition will no longer be met and even the balanced condition may not apply, so reinforcement at d may no longer reach yield. RAPT accounts for this in its calculations. This is similar to the latest ACI-318 logic setting a Tension Strain limit to define compression ductility rather than defining a balanced section limit.
- AS3600 beam Shear calculations modified to the Modified Compression Field logic in the 2018 code. This will normally result in more shear reinforcement required than previously required by earlier versions of AS3600. Selecting AS3600-2009 as the design code will still use the old calculation method. This section in AS3600-2018 is currently under review and RAPT has used the more conservative option (and we think the correct option) until this review is finalised.
- Minimum shear reinforcement is still based on the 2009 code rules with the definition of a band beam increased to 5 times the depth of the section.
- Minimum spacing requirements are still based on the 2009 code rules. This section in AS3600-2018 is currently under review.
- Additional Longitudinal Tension Reinforcement for Shear is now based on the deltaFtd logic in AS3600-2018, where deltaFtd = V* cot(theta), for all versions of AS3600 design rules rather than the tension force offset logic used previously.
- RAPT still does not check specifically for Robustness and does not add the minimum integrity reinforcement now required in AS3600 clauses 2.1.3, 8.3.1.1 and 9.2. This is regarded as Detailing reinforcement and is not included in RAPT as part of the flexural reinforcement.
- RAPT does not include Steel Fibre reinforcement as a design option. In our opinion, it should not be considered to provide flexural strength in any situation where plastic redistribution is required for ultimate strength (Fire, Earthquake, Moment redistribution). We will look to include it for Shear in a future RAPT release.
- RAPT does not include the new Capacity Shear requirements of clause 14.5.2.2 for earthquake design. This will be included in a future release.
The biggest difference AS3600 designers will notice is in the Shear design. It is important that designers iterate the design by importing the designed reinforcement into the RAPT input as User Defined Reinforcement and rerun. This will affect both Shear and Deflection results as the rerun will be based on the nominated reinforcement pattern rather than the Ast required for flexure at each design location.
In the shear calculations for Vuc, RAPT uses the General Method. AS3600 also offers a Simplified Method but it is limited in its applicability and has several built in assumptions that are not obvious to the designer. The General Method differs from the Simplified Method in that the General Method allows for the specific reinforcement at each design section, while the Simplified method assumes that the reinforcement available at each location is that required to account for the bar termination detailing provisions of AS3600. Without Iteration of design as mentioned above, the shear capacities calculated by the General Method will normally be lower than those calculated using the Simplified Method and more transverse shear reinforcement will appear to be required as the reinforcement used in the calculations at points away from the peak moment points will not include reinforcement for longitudinal tension force from shear and detailing reinforcement.
2 For all design codes, additional Longitudinal Tension Reinforcement for Shear is now based on the a tension force = factor * V cot(theta) rather than the D offset or tension force offset logic used previously. For Eurocode using the logic that Vc = 0 with transverse shear reinforcement, factor = .5 as defined in Eurocode. For all other codes, factor = 1. Theta is defined as the shear strut angle in each code. Australian pre AS3600, Indian, South African, ACI318 and pre Eurocode versions of BS8110 use 45 degrees.
Changes in v6.5.18.0 - 28/01/2019
1 Improved ductility design routines especially where non-standard faces are in tension, eg with reversal loading.
2 Fixed problem with ductility checks for cases where the selected neutral axis deptyh limit is higher than the code limit and the depth to the tension force is relatively small compared to the overall depth.
3 Fixed problems with final reinforcement bar size selection in cases where the required bar size is smaller than the minimum bar size selected.
4 Fixed problem in reinforcement bar size selection in cases where the design code gives no maximum spacing limit.
We are currently working on improvements to deflection calculation, especially in cases where RAPT gives a discountunuity in the deflection diagram. We are also working on the AS3600-2018 changes.
Changes in v6.5.17.0 - 21/09/2018
1 Added option to print multiple result sets in one operation. Start RAPT with no data file loaded and select Print File from the File Menu. After setting the printer, RAPT will offer a file selection dialog. Select the RAPT files to print and tell RAPT to proceed. Each file will be loaded into RAPT. If its current state requires recalculation, RAPT will run the calculations and print the file. Each run will be printed to a separate file if sent to a PDF writer. The RAPT user can then use a PDF program to merge the files if they want them to be in one continuous PDF file.
2 Provision has been made to allow the definition of Metal Decking for multiple manufacturers and for users to add other profiles. The desired manufacturer is selected in a newly introduced General Input Grid in Default Materials - Metal Decking.
3 Fielders KF40 decking data has been modified at the request of the supplier. Only 3 Pan KF40 is now available and .6mm sheet is no longer available for this decking profile.
4 Stramit Condeck has been added to the Australian Materials defaults file.
5 We have fixed a bug in the crack control checks in RAPT in situations where a design code specifies a maximum bar size for crack control (AS3600 and Eurocode) and the maximum bar size allowed due to stress levels is the smallest bar available in the materials list. The problem then shows up if the required bar spacing is smaller than the minimum bar spacing allowed. Normally RAPT should give a result with the maximum bar size as the selected bar size with the small spacing and a warning that the designer needs to sort out the problem, probably by defining a stress limit in the RAPT input to force a larger size to be required. IN the case where the problem occurs, RAPT currently adopts the Preferred Bar Size rather than the Code Maximum Bar Size for Crack Control and does not give a warning.
6 Fixed bug in the use of Reinforcing Mesh as Program Calculated reinforcement in Design Zones.
7 Fixed bug in the calculation of tension force in webs of metal decking that do not extend full depth of the deck profile.
8 Added shear results for Minimum Number of Shear legs to the Detailed Reinforcement Output.
9 Fixed bug in calculation of default Concrete Weight in US Imperial units.
10 Fixed Fielders KF70 .9mm sheet thickness Mechanical Resistance in the Australian Materials File. It was previously set to 0.
Changes in v6.5.16.0 - 07/02/2018
1 For very long members (greater than 150m) with elements, a float accuracy error in C++ was causing RAPT to incorrectly position elements past that point, in both loading calculations and section properties. This has been fixed.
2 In shear calculations for the Canadian Code, the shear depth for flexure shear calculations was incorrectly calculated for reinforced concrete members.
3 In shear calculations for AS3600-2009 for the minimum shear reinforcement area was always calculated as .35bd, missing the concrete strength based limit added in 2009 for higher strength concretes.
4 In prestress input, when the time of stressing is changed, the concrete strength at that time is recalculated. This was not allowing for the conversion from Cube Strength to Cylinder strength and vice versa where a cube strength Design Code ode or materials data set is used.This has also been fixed in the prestress losses calculations. The problem was introduced when designers started using Eurocode for countries that use Cube strength for concrete.
5 In prestress data checking, the check on minimum spacing was based on logic for post-tensioned bonded tendons. This has been changed for
- pretensioned concrete to give a error when the spacing is less than 4 times strand diameter with a maximum of 50mm and a warning if less than 4 times strand diameter.
- post-tensioned concrete an error if the spacing is less than duct width + 60mm, and a warning if the spacing is less than 4 * duct width.
6 We have added a warning for flat slabs regarding reinforcement concentration over the column. RAPT cannot calculate the concentration required by many codes as it does not know anything about the transverse positioning of the tendons. Most design codes require that some of either the column strip reinforcement or the total reinforcement be concentrated in a strip concentrated over the column normally about D to 1.5D either side of the column. This should apply to all structures requiring two-way action, including band beam and slab structures.
7 In detailing reinforcement where the designer requested that a minimum amount of reinforcement extend to supports, RAPT was sometimes confused when the "support" surface and "span" surface were inverted, eg for upwards loads.
8 In the Frame Properties output data, we have added the column height above and below used in the stiffness analysis.
9 In the prestress Secondary effects output, where tendons were terminating, RAPT was still providing prestress forces and eccentricities at locations where the tendon was not reaching the end of the span. This has been fixed. It did not affect the calculation of the Prestress secondary effects, only the reporting of the numbers used to calculate the final effects, so had no effect on design results.
10 In the flexural design, the logic in RAPT for determining plastic hinge locations was based on downward loading, so RAPT looked for support plastic hinges at negative moment zones at supports and span plastic hinges at the critical positive moment point in the span. This has been modified to recognise the possibility of the an upward load condition being critical. RAPT checks for the overall load direction for the frame based on the sum of the reactions to decide which direction controls.
Changes in v6.5.15.0 - 12/08/2017
1 IN cases where the Concrete Type (cube/cylinder) is set differently in the RAPT Design Code Data File and the RAPT Materials Data File, the strength was not being modified to suit the design code formulae for Prestress Transfer calculations. This situation happened generally in countries that use Cube strength for concrete and Eurocode, which is a Cylinder Strength Code.
2 In Column Slenmderness calculations, if the designer nominates only mininal applied moments, RAPT now sets both M1 and M2 to the minimum moment.
We would like to point out that it is important that designers calculate the correct moments for the column. As an example. I was sent a file recently with a 1200mm square column with 2.4% reinforcement and the designer had specified the M1 and M2 values for slenderness as 0. And wanted RAPT to magnify these moments. This is not logical. The actually applied moments must be used to then determine the Magnified moment. Designers should NOT assume columns are pin ended to determine the moments and then expect to get a realistic magnified moment for design from RAPT. The analysis of the structure must reflect the true stiffness of the structure. Most design codes suppest using full uncracked member stiffness for analysis for vertical loads, and that includes for columns.
3 Added Design Code and Materials files for Sri Lanka BS8110 and Sri Lanka Eurocode 2.
4 Modified Load Factor for eEarthquake loads for Europe, Singapore and malaysian versions of Eurocode Design Code to a factor 0f 1.0.
Changes in v6.5.14.0 - 23/06/2017
1 Add checks on number of bars and spacing of bars in User Defined Reinforcement Input and number of tendons and spacing of tendons in Prestress Input to try to trap obvious input errors.
2 Eurocode punching shear calculations - determination of rounded corners for the perimeter calculation was sometimes resulting in negative perimeters for edge columns where the column was nearly fully external to the concrete edge.
3 D-offset reinforcement calculations for span face reinforcement were incorrectly allowing for user defined reinforcement.
4 removed the option to allow mesh reinforcing to be used as shear reinforcement. If a designer wishes to use mesh reinforcement to contribute to shear capacity, they should subtract the area provided from the area required calculated based on normal bar reinforcing ties.
5 Added option to print multiple result sets in one operation. Start RAPT with no data file loaded and select Print File from the File Menu. After setting the printer, RAPT will offer a file selection dialog. Select the RAPT files to print and tell RAPT to proceed. Each file will be loaded into RAPT. If its current state requires recalculation, RAPT will run the calculations and print the file. Each run will be printed to a separate file if sent to a PDF writer. The RAPT user can then use a PDF program to merge the files if they want them to be in one continuous PDF file.
6 In allowing for limitation of reinforcing strain to accommodate FRP materials, the prestrain due to prestress was not being reset to 0 for user defined reinforcing materials. This has been fixed.
7 Slenderness calculations to BS8110 and derivative codes were incorrectly allowing for the creep factor. This has been fixed Note there is actually no creep factor in BS8110 for this. We would suggest the use of the AS3600 factor Beta3 = DL / (DL + LL).
Changes in v6.5.13.0 - 03/03/2017
1 In the previous upgrade, an improvement was made to the Creep calculations for both prestress loss calculations and the deflection calculations. THis should have led to a slight reduction in deflections.
2 Since Windows 8, we have had a small number of users have problems with the numbers showing in data cells sometimes not showing the last character eg recently for 1 user, 16800 was showing correctly in edit and output, but not in the normal cell where it was showing as 1680. This is caused by the mathematical calculation required to estimate a cell length and the character string length. We had increased the margin of error to over come the error in the comparison, but obviously it still fails sometimes. So we have now added an option in User Preference - Fonts to allow the user to nominate a margin if the numbers are not showing correctly. Default is 10. If you have a problem, gradually increase this until all numbers show correctly (in the case above 13 worked).
3 Fixed minor error in determining reinforcing D offset requirements at point of contraflexure for members with very low L/D ratios.
Changes in v6.5.12.0 - 12/02/2017
1 In the 6.5.9.0 release, an error was introduced into the tension stiffening calculations for estimation of deflections, leading to an underestimate of expected deflections. This has been corrected.
2 The current AS3600 shrinkage calculation formulae give very low estimates of shrinkage for higher strength concretes (above 50Mpa). We discovered this while collaborating with Boral on their new Envisia concrete products which are included in RAPT's materials data. Information on the problem with possible solutions has been passed on to the AS3600 committee for consideration for the next release of AS3600. In the meantime, we have adopted a solution in RAPT which gives good agreement with available concrete test data. It may not be the solution that is eventually adopted in AS3600 20** but at least gives designers a much more sensible estimate of shrinkage effects for higher strength concretes.
3 Shrinage effects for deflection in RAPT have always been calculated from time t = 0, as the shrinkage warping efefcts start when shrinkage starts. Creep efefcts have always been based on the time of loading. This does nto allow a designer to investigate the effects of different loading over time.
We have added an extra data item in Design Data - Deflection to nominate if the deflection calculation is for Full Shrinkage (assuming start at time t = 0) or for Incremental Deflection (assuming shrinkage starts at t = time of loading). Creep is still based on the period from t = time of loading to t = loaded period).
If the designer is simply looking at a single stage loading from time of loading, this should be set to Full Shrinkage.
If looking at multiple loading stages, the designer should do the first stage using Full shrinkage (from t = 0 to t = end of 1st stage, creep will still be from t = time of loading) and then later stages as Incremental Shrinkage (from t = start of stage to t = end of stage).
4 Added Boral Envisia Gold and Platinum concrete options to Australian Materials data.
5 Made some changes to the Help files to being them up to date in many areas.
Changes in v6.5.11.0 - 17/01/2017
1 A bug was introduced into the beam shear calculations for all codes other than Eurocode in the last release. This is affecting the amount of shear reinforcement required in all cases where more than minimum shear reinforcement is required. Users should update RAPT on all computers to this latest version immediately and check shear calculation results for any heavily loaded members from the last release.
Changes in v6.5.10.0 - 07/12/2016
1 Fixed rounding error problem in the service stress calculations introduced in the last release. This only occurred at very low concrete strain levels (less than .0001) so had very little effect on the calculations but the warning message was annoying.
2 Eurocode Shear calculations - where shear reinforcement is required, Eurocode sets Vuc = 0 and reduces the applied shear by the effect of tendon slope before calculating the required shear reinforcement. If the tendon slope effect is greater than the applied shear, this results in a negative shear force in the shear reinforcement calculation. RAPT is not currently checking for this possibility and is giving a negative shear reinforcement spacing. We have changed this to set the Vvs value to zero and add minimum shear reinforcement at the cross-section.
As well. RAPT was setting the reinforcement material factor in this calculation to 1 instead of 1.15. This has also been fixed.
Changes in v6.5.9.0 - 22/08/2016
1 Fix load balancing in prestress input screen for point loads applied at the free end of cantilevers. This does not affect analysis and design calculations, simply the load balancing option in input to determine the starting tendon profile and number of tendons.
2 Fix the calculation of the curvature for the slenderness calculations for columns. In most cases RAPT was overestimating the curvature and therefore over-estimating the buckling load and the moment magnifier or the extra eccentricity for BS8110 and Eurocode.
- RAPT now requires the designer to define the Beta factor for each design code which allows for the creep effects, normally based on the ratio of permanent load to ultimate load or dead load to total load depending on the design code. RAPT will then use that factor as defined in each design code. For Eurocode it will also calculate the concrete Creep factor for the section for the loaded period (from Time of Loading to Losded Period) to use with the Beta factor.
- RAPT now calculates the Secant Stiffness (EI) at the point where the line from 0,0 through the Mp,Np point intersects with the interaction curve calculated based on short term concrete properties. The extreme compression concrete strain and neutral axis depth determine the curvature and EI is calculated from M / curvature. This gives a constant value of EI for a specific Mp,Np point. RAPT does not use the approximate EI formulae in most codes e.g ACI318 gives 3 separate formulae which have different levels of accuracy.
- AS3600 says it conservatively uses the curvature at the balanced point, but in fact uses phi times that curvature with phi = .6. We had missed this previously and have now included the phi factor for AS3600 even though we consider it to be overly conservative, especially as RAPT is using a curvilinear concrete stress/strain curve which is significantly more accurate and more conservative than the rectangular stress block.
- RAPT now includes the extreme compression concrete strain, the curvature and the resulting EI in the text output for each point on the curve.
3 Added an extra toolbar icon to assist in determining values on the interaction curve. The designer is asked for a Mp,Np point and RAPT will then define the intersection points for
- the vertical line through that point with the interaction diagram giving the Axial force value at the intersection with the interaction curve for the defined Moment.
- the horizontal line through that point with the interaction diagram giving the Moment Value at the intersection with the interaction curve for the defined Axial Force.
- the diagonal line from 0, 0 though the nominated point with the interaction diagram giving the Moment and Axial Force
When a new point is selected, the old values will be cleared, so if you want a copy, you will need to print the screen before nominating the next M,N point.
4 Several years ago when we were forced to change the install program that we use for RAPT, we modified RAPT to use the Windows User logic for the storing of and access to default files for RAPT. The result was that designers could only have 1 RAPT version on a computer, stopping them from maintaining older versions on the same computer for specific projects.
We have modified this logic so that any RAPT directory outside the Windows Program Files (x86) directory will now use the copy of the defaults files saved in sub-directories in that directory rather than the one controlled by the Windows User logic. This can only work for future RAPT versions. To maintain an older version in future, copy the RAPT directory from Program Files (x86) to an area outside Program Files (earlier RAPT versions simply created directories in the C: drive). Then when you install the new RAPT version, it will over write the Program Files version and the defaults files in the User area, but your copied version will still work and access its own defaults files.
You will need to maintain screen shortcuts and sort out your own naming convention for shortcuts so that you know which version you are using.
Changes in v6.5.8.0 - 10/07/2016
1 Eurocode option for Ultimate Load Combinations based on Equations 6.10a and 6.10b in the General data screen has been applying incorrect combination factors for Superimposed Dead Loads for the combination based on full LL factor if the special Dead Load combination factor is less than 1. This has been fixed. Any run already created using this option will need to have the combinations recalculated, or over-ridden manually. The easiest way to force a recalculation is to set the option back to Eqn 10 and then back to 6.10a and 6.10b.
2 In Text description fields, RAPT does not limit the length of the text. This causes problems with printing if the text extends past the end of the line on a page. In creating the printed report for the printer, if RAPT detects that the text name is too long, it will now indicate which lines of data are causing problems and offer the user the option to either
- continue printing with the text truncated to fit on the line
- terminate the printing to allow the user to modify the text before printing again.
3 In calculating the interaction curve for circular sections, RAPT will sometimes give one M, P point which does not fit logically on the curve. This has been fixed in this version. All other points on those curves were still correct.
For those waiting for the changes to the Slenderness calculations, they are progressing and should be ready in a couple of weeks. A new release will be made when they are ready.
4 Added output for shear for
- phi * Vus (shear required to be carried by the reinforcement = V* - phi Vuc, except for Eurocode where it is the full applied shear if shear reinforcement is required) and
- Theta, the angle of the shear strut used in the shear calculations at that location.
5 Sloping surfaces cause a lot of problems in determining reinforcement offset requirements to satisfy the truss analogy for shear as is required in most design codes. RAPT was crashing with a slope of 45 degrees (division by 0) and inconsistent in other areas, especially where there are several connected slopes in reverse directions. This has all been reprogrammed to handle any combination of slopes logically. We have also modified the calculations for force development at contraflexure points to be consistent with this methodology and to limit the tension force to be developed to that required at the peak moment points.
It is important that designers identify when a strut-tie analysis is the logical solution in a design. RAPT only designs flexural members. Whatever you define, RAPT will assume it is a flexural member.
For short spans with deep members (Deep Beams), the designer should investigate whether strut tie is the more logical solution. Also, where concentrated point loads are applied near supports, strut tie logic may be the better solution, even though the overall beam is still flexural.
6 Several other minor fixes made.
Changes in v6.5.7.0 - 02/01/2016
1 Fix input error check that does not allow modification the right end of elements that extend into the Right End Zone of a fram part the right end column.
2 Fix analysis problem related to UDL loads that are completely within the Right End Zone to the right of the right end column.
3 Fix incorrect Peak Stress data for reinforcing bar and mesh in Singapore, Malaysia and UK Eurocode material files.
4 Fix development zone strength calculations for pre-tensioned strands to Eurocode. RAPT was grossly underestimating the stress in the strands in the development zone.
5 Fix development zone stress calculation problems for all design codes for pre-tensioned strands where extra user defined reinforcement is also added.
6 Fix prestress force calculations for unbonded prestress strands.
7 Fix stress/strain calculation for prestressing steel to the current Eurocode. Previously, RAPT has been using a stress/strain relation similar to that in BS8110 from the first version of Eurocode.
8 Introduced an Input Error if Shear Enhancement is selected for Eurocode. RAPT does not allow this to be set in the Input, but we found that old Code Defaults files had it set and did not allow it to change.
RAPT cannot do the Eurocode Shear Enhancement calculation as the "enhancement" can only be done by reducing the shear due to loads applied within 2.D of the face of the support during the analysis.
9 Modify treatment of secondary moments for pre-tensioned members to include secondary moments if requested by the designer. In the last few versions RAPT has not included secondary effects for pretensioned strands, then later we gave the designer the option to ignore them for any tendon (default is to include for post-tensioned tendons). When this later option was added, the designer could also set it for pre-tensioned tendons to include secondary prestress effects but RAPT ignored this in the calculations. Now RAPT does what it is told.
10 Fixed division by zero error that happened intermittently with metal decking in a situation where the service stress was essentially zero.
Changes in v6.5.5.0 - 24/06/2015
1 Significant changes have been made to the default Code and materials files for several codes/and countries. We are therefore forcing all RAPT users to select new Defaults files at installation. If you want to use an old user defined materials file, make sure that the relevant changes discussed below are made to the old file and then save the file so that it has the current version number.
2 Added an option in Materials Data for multiple Concrete Types. RAPT will always define the standard concrete type for each country in the defaults issued with RAPT. Users can now add other concrete types with materials properties different to those in the standard concrete. In the Materials Defaults - General Screen, there is now an option to nominate which Concrete Type is the Default type to be used for any new RAPT run as well as the default strengths to be used.
In the General Input Screen for any RAPT run, there is now a Concrete Type option immediately above the Concrete Strength option.
3 For Australian materials, RAPT now defines 4 different concrete types. The first 3 are the standard concretes previously defined in the 3 separate materials files for Brisbane/Sydney, Melbourne and Australia (with different shrinkage values). Separate Materials files are supplied in the installation program with each of these zones set as the default. The installer will be asked to select one as the Australian Materials Default file. The relevant file is then copied to the defaults directory as Australia.rmc so that there will only be one Australia Materials file defaulting to the selected shrinkage properties. The default Concrete Type can then be modified in File - Open Defaults - Materials for new runs, or the Concrete Type can be modified in a run file in the General Data Screen.
The 4th concrete type defined is the new Boral ENVISIA® concrete, currently available in Sydney, Sydney regions and ACT. As well as improved durability properties, this concrete has significantly reduced Shrinkage and Creep properties. Its use should result in a reduction in deflections of 15-25% depending on the design situation as well as reduced shrinkage cracking. Contact your local Boral representative for availability, pricing and information on its properties.
4 In Materials Defaults, when the shrinkage strain is modified, RAPT will check if the value is appropriate for the code selected (eg no shrinkage is nominated for BS8110 and Eurocodes as the value is built into the calculation method. Shrinkage/Creep multipliers can be used to check for the effect of high or low shrinkage values in these codes.) and for AS3600, RAPT will offer a dialog asking for information about the data defined. The basic shrinkage in AS3600 is a 30 year value (800/900/1000 microstrain). If a 56 day test value is defined, it needs to be converted to a 30 year value to be defined in RAPT. RAPT will ask for this data. If it is a 56 day test value, RAPT will convert it to a 30 year value using the code shrinkage formulae, using the same methodology as the example in the new AS3600 Commentary. If the designer specifies that it is a 30 year value, RAPT will use the value defined to calculate the design shrinkage properties.
5 For bonded post-tensioned tendons, RAPT has previously treated the tendons as bonded at all stages of design. However, at transfer, the tendons are normally not bonded and the volume of the duct is essentially empty. If this duct is in the compression zone, it is essentially a void in the compression concrete. Normally this has very little effect as the volume of ducts in most members is very small. However, for some members, such as bridge I beams, there is a large volume of ducts in what is normally the tension zone, but at transfer with the large amounts of prestress involved is a compression zone. Normally these members are pretensioned, so there are no ducts. But when there is not a pretensioning plant nearby, they are often post-tensioned.
In the same way, for unbonded tendons RAPT has previously assumed that the duct does not exist when it is in a compression zone, so the concrete is still included.
This logic has been modified in this new version. At Transfer, Prestressing ducts are now assumed by default to be voids if in the compression zone, unless the designer nominates otherwise. And the tendon is assumed to be unbonded, so the stress in the tendon will not change due to changes in the strain in the surrounding concrete, again unless the designer nominates that the tendon is bonded at transfer (only possible for bonded post-tensioned tendons).
Normally post-tensioned tendons will be ungrouted at transfer. However, in some transfer beams, where stage stressing is used, at different stages some tendons will be grouted and others ungrouted. If is up to the designer to over-ride the RAPT default for the grouted tendons in this case.
Obviously, pretensioned tendons are always bonded, and unbonded tendons are always unbonded at transfer and an option is not provided for these cases.
6 3 extra data items have been added in Prestress Details data screen. These are
- Include Secondary prestress Effects
RAPT automatically includes Secondary Prestress effects in the calculations for all post-tensioned tendons. A few versions ago, we stopped including these for pre-tensioned tendons as normally pretensioned members are stressed in a situation with no continuity, where there are no secondary prestress effects, but are often then included in an indeterminate frame as composite members.
Some users have since requested that the same option be made available for members that are precast but post-tensioned and then included in an indeterminate frame.
This option now allows the designer to over-ride RAPT's default treatment of Secondary Prestress effects in all cases. The RAPT default will still be the same for the different prestress types whenever a new tendon is added.
- External Tendon
For bonded post-tensioned tendons, the designer can now nominate that a tendon is External. If selected, the tendon will be treated as an Unbonded Tendon in design, but will still use the Bonded Tendon material properties such as friction etc. This allows a mix of bonded and unbonded tendons to be included in a design at the same time as often happens in box girder and superT bridges. The design will still be considered to be a bonded prestress design overall and the normal unbonded member minimum reinforcement rules will not be applied. It is up to the designer to ensure that the resulting design is logically correct in terms of allowable stresses and minimum capacities as RAPT will allow all tendons to be external, effectively resulting in an unbonded member.
- Grouted at Transfer
As discussed above, normally bonded post-tensioned tendons will be ungrouted at transfer. However, in some transfer beams where stage stressing is used, at different stages some tendons will be grouted and others ungrouted. If is up to the designer to over-ride the RAPT default for the grouted tendons in this case for each stressing stage (we always recommend that tendons be grouted as soon after stressing as possible to ensure they are properly protected and are acting as bonded tendons for load carrying requirements during construction).
RAPT will by default, assume that any bonded post-tensioned tendon is ungrouted at transfer. In special cases, the designer can nominate that any particular tendon is grouted. If ungrouted, the duct will be assumed to be a void in the concrete if it is in the compression zone, this reducing the compression area of the concrete and probably increasing the compression stress in the concrete as well as effecting the tension stress. Under deformation, the tendon will be assume to not change strain as the concrete around it undergoes changes in strain.
7 Shear Stirrups - Previously RAPT has defined 3 default bar sizes in the Material Defaults files for Shear Stirrups. And has provided results for 2 (by default) of each of these sizes of stirrups. The designer could change the number of legs in each stirrup set to any number desired. In recent versions, RAPT has also nominated the minimum number of legs required for each set of stirrups, but has not provided design spacing requirements for the minimum number of legs. We have made several changes in this area-
- Materials Defaults
We have changed the Materials defaults for shear reinforcement to nominate the same bar size for all 3 stirrup sets. For Australia, this is set to 12mm. For all other codes, it is set to 10mm. Designers can change them to any default desired.
- Reinforcement General
For the 3 shear reinforcement default options, RAPT will check the size of the bars and the steel type, and, if a bar size repeats, will add an extra 2 legs to that stirrup set. So, if the same bar size is nominated for all 3 sets of stirrups, RAPT will define them a sets of 2 legs, 4 legs and 6 legs.
- Shear Results
RAPT will now give results for the 3 stirrup sets nominated in the input, plus a stirrup set with the minimum number of legs at each design location. This number could vary depending on the beam shape, so the designer needs to check at each location for the number of legs used in the calculation at that location. This "minimum legs" result uses the smallest bar size of the highest strength of the 3 nominated bar sizes to determine the spacing requirements. The Min Legs result is now the result that has the spacing nominated for each span, denoted by the "*" as it is really the minimum required (previously the middle of the 3 set types was used as the "*" option.
The Minimum Number of Legs required at each design point is now defined on the graphics, using the right had scale to define the values, while the spacings are defined on the left hand scale. The minimum number of legs will drop to zero where no shear reinforcement is required.
8 Ultimate Load Combinations for Eurocode based on Eurocode 1990
- Eurocode 1990 gives 2 separate options for Ultimate Strength combinations. Previously, RAPT has used equation 6.10 and the user has had to manually over ride the combinations if they wanted to use the alternate equations 6.10a and 6.10b. RAPT now includes an option in the General Input Screen to select the combinations to use. The default is still always 6.10, but the user can change this to 6.10a/b in this option. Note Eurocode gives no guidance as to when each combination should be used.
- Equations 6.10a/b require an extra data items to define the Reduction Factor xi in Eurocode 1990. The default in Eurocode is .85, which results in an Ultimate Dead Load factor of 1.15, instead of the 1.35 in equation 6.10. This is very low. BS EN1990 adopted by UK, Singapore and Malaysia has nominated a value of .925 for xi, which results in an Ultimate Dead Load factor of approximately 1.25.
RAPT has included this xi Factor in the Code Defaults for Eurocode based codes as a Partial Load Factor Tm (able to be viewed and modified in the Loads Combinations screen using the Building Type Toolbar Icon). The default in RAPT materials for the basic Eurocode is .85 as per Eurocode 1990. The default in the BS based Eurocode Defaults files for UK, Singapore and Malaysia is .925. RAPT will not let the factor be < .85 or > 1.0 and will give a warning if it is < .925.
In the Load Combinations Description field, RAPT will call Equation 6.10b Live Load combinations as the full live load factor is used with a reduced dead load factor and Equation 6.10a Load Combinations Dead Load combinations as the full dead load factor is used with reduced live load factors.
9 Characteristic Service Load Combination
In Eurocode 1992, serviceability checks are done based on the Frequent or Quasi-Permanent Load Combinations depending on the situation. But the decision as to whether or not a section should be considered to be cracked for these calculations is based on the Characteristic Load Combination. We have added a Characteristic Service Load combination in Loads - Load Combinations in the input. The only difference from other Service Load combinations is that the Live Load cases have a factor of 1 rather than the reduced factors for other serviceability combinations.
For design codes other than Eurocodes, this combination also gives the full service load for columns and footings, a combination that RAPT had never previously calculated as it was not needed for the frame member design. So it has been included in the Column Actions summary output as well.
10 Crack Control and Minimum Reinforcement for Eurocode
The stress results of the Characteristic Service combination are now used for Eurocode 1992 to decide if crack control checks under the other combinations are required for prestressed section design. Crack control checks are still carried out for the Frequent and Quasi-Permanent load combinations and results reported if the stresses under the Characteristic Combination require them.
11 Tension Stiffening
The Modified Tensile Modulus method we use recommend designers use for our tension stiffening model in RAPT is dependant on the tensile strength of the concrete. For cases where the designer has selected, in Design Data - Deflections, to reduce the tensile strength of the concrete from the standard code value, RAPT has continued to use the code defined tensile strength rather than the reduced strength for the tension stiffening model. We have modified this to be consistent and now use the user defined tensile strength of the concrete for the tension stiffening model as well as in determining whether or not each cross-section is cracked.
12 For prestressed flat slabs designed by average moment methods (from ACI/PTI design theory), we have added limits to stresses required for this design method but not nominated in some design codes. This occurs because these codes do not necessarily agree with the logic. But RAPT allows the design method (though warns against its use) so we have tried to apply logical limits. For Canada, we have included the ACI limits. For other codes that do not cover this, we have applied the British Concrete Society TR43 table 4 limits.
This design methodology should definitely not be used where the applied loads are not uniform eg transfer slabs or when the section shape is not uniform eg with drop panels or band beams. In these cases logical design strips and tendon layouts which fit both the load pattern and concrete shapes should be used.
13 General interface and minor calculation fixes.
Changes in v6.5.4.0 - 21/01/2015
1 Fix Install program implementation of the changes for Design Code Defaults and Materials Defaults for Singapore, Malaysia and UK for Eurocode 2 design code.
2 Modify wording and symbols for Slenderness Moments for Sway Column design cases for AS3600.
3 Entering Elements in the input has caused a crash in some cases for several years but we have never been able to diagnose the cause of the problem. Someone has finally been able to provide a repeatable procedure to recreate the problem and this problem now appears to be fixed.
4 Concrete shapes with very shallow triangles or trapeziums have sometimes given unusual results, especially at service. Though the math used to generate the concrete forces is correct, it is giving unusual answers in these cases . We have provided an internal workaround to treat these shapes as a series of rectangles of the same area to ensure that this does not happen while we try to solve the mystery of the sometimes unusual results.
Changes in v6.5.3.0 - 10/11/2014
1 In the 6.5.2.0 release, the new general Defaults Material File for Australia, Australia.rdc had a new default variable Creep Multiplier set to 0 instead of 1.0 as the default value. This resulted in 0 creep factor for deflection calculations. This has been fixed in the new material file in this release. The default value was correct in all other default materials files.
2 We have added a data check to make sure a low number is not used accidently for this variable. A warning will be given if the value is less than .4 and an Error if it is less than .1.
Changes in v6.5.2.0 - 20/10/2014
1 Moving load cases with a combination of UDL loads and point loads with a length were showing correctly on the graphics, but the point loads were being offset to the right by half of the load length. This only affected results where the point loads were combined with distributed loads.The effect was relatively smal on normal spans but was very obvious for short cantilevers with point loads with a relatively long length of application.
2 Flexural Reinforcement added for Shear for the truss analogy was showing in the Ultimate Graphics view and the Detailed reinforceemnt screens, but not in the Flexural Reinforcement - Total Reinforcement text view. This has been added.
3 A problem with Concrete Strength range in the column module has been fixed. RAPT was crashing trying to generate the graphics viewin the latest release.
4 Added changes from HK CP 2004 to HK CP2013
5 Created Design Code Defaults and Materials Defaults for Singapore, Malaysia and UK for Eurocode 2 design code.
Changes in v6.5.1.0 - 10/10/2014
1 Modified calculation of Theoretical Thickness for shrinkage and creep calculations to handle unusual cases with rectangular beams without slab flanges depending on the value of the "nominal" slab depth nominated relative to the beam depth. Previously RAPT's calculation for this gave different results in cases where the "nominal" slab depth was less than the beam depth (no exposed perimeter reduction) or equal to the beam depth (illogical result as the beam sides were assumed to not be exposed).
In this modification, if the slab panel width is exactly the same as the beam width, then
- if the member type is nominated as Beam, all faces will be assumed to be fully exposed in the calculation of the theoretical thickness.
- If the member type is nominated as Slab, then the sides of the defined slab depth will be assumed to be continuous and not exposed for an Internal Panel. For an External panel only the internal face will be assumed to be continuous and not exposed, while the external face of the slab depth will be assumed to be exposed.
It is important that designers model the actual member they are trying to design, not some simplification (eg rectangular beam rather than a T-beam) as this can affect results in unusual ways, sometimes unconservatively.
Changes in v6.5.1.0 - 07/10/2014
1 Fixed error in partial shear analysis for triangular load shapes.
Changes in v6.5.1.0 - 01/10/2014
1 Fixed treatment of circle elements in members where the top of the member is not at the datum in the main frame program.
2 Fixed calculation of reactions in the column actions for the moment controlled envelope for moving load envelopes in cases with no column stiffness and therefore zero column moments. The case of M = 0 was not allowed for. Reaction controlled envelopes were always correct.
3 Fixed checking routines for determining connecting tendons for couplers for cases involving unbonded prestressing tendons.
4 Minimum reinforcement requirements set in Design Zones in tension only cases. In some cases, RAPT is defining the need as a Minimum Reinforcement requirement when in fact no reinforcement is required as there is no tension moment on that face of the member. The reinforcement is not actually being added as required in the total reinforcement requirements at the section, only in the Minimum value. This has been fixed.
Changes in v6.5.0.0 - 14/09/2014
1 In Version 6.4 we began the conversion of the prestress calculations in RAPT to allow for the variation of the prestress force along the whole tendon rather than using the average force in each span (some software actually uses the average force in a whole tendon!). Pre version 6.4, RAPT used the average force in each span to calculate the prestress moment diagrams. This often led to inconsitencies at column lines where the average changed and also with changes in section where the average could be misleading.
In Version 6.4, the change to using the actual prestress at each point along the tendon for prestress actions calculations was introduced for the Primary Prestress moment (P.e) but the Secondary Prestress effects were still determined from the average prestress force in each span.
In Version 6.5, we have now changed the Secondary Prestress effect calculation to account for the prestress force variation along the tendon also. So all inconsistencies should now be removed. This means that RAPT no longer relies on load balancing logic to calculate the prestress moment diagrams as load balancing logic is based on average forces in each span. RAPT still reports the Tendon Actions based on load balancing in the Prestress Actions report to give the designer an idea of the load balancing effects, but it does not use these results to calculate the prestress bending moment diagrams. Instead the secondary prestress effects are now calculated by analysing for the effect of the applied curvatures from the prestress on the indeterminate structure while the primary prestress effect uses the prestress force at the location being calculated and its eccentricity from the gross concrete centroid. This results in the most accurate possible analysis of the prestress effects and allows RAPT to fully account for the prestress force losses at dead end anchorages and in the transmission lengths of pretensioned strands.
2 Finished modification of Moment Redistribution to provide more correct redistribution and provide the most economical result for redistribution. RAPT now has two redistribution methodologies depending on the load types defined
- Basic redistribution (old method pre version 6.3) The overall design envelope is calculated and then the whole envelope is redistributed by the requested percentage. This is now only done for cases where Moment Envelopes are defined. This includes Moving Load cases.
- Complex Redistribution is now done for all other load situations. In Complex redistribution, each individual load combination is redistributed in the direction indicated by the designer and by a maximum of the amount requested but not by an amount that will result in an increase in the moment on the other face. To explain the procedure, For a redistribution from Support Hinges to Span,
- The un-redistributed Envelope is calculated. The maximum amount of redistribution is then calculated from the peak moments at the supports in each span, except at end columns where no redistribution is allowed.
- The individual load combinations are then recalculated and each combination is compared to the overall envelope. The redistribution is then applied to this combination but only to the extent that it reduces the critical Span to the maximum of the envelope of all of the combinations.
The overall effect is to compress the overall envelope, rather than shift the overall envelope. For +ve redistribution, the -ve moments are reduced towards the peak +ve moments and vice versa for -ve redistribution.
For negative redistribution, the same approach is taken but the redistribution is based on the maximum span moment. In this case, as increasing the support moments will increase the moment transfer to the columns, the redistribution is limited so that the moment transfer to the columns is not increased.
3 Fixed problem in Pattern Load de-selection in Design Data - Pattern Loads.
Changes in v6.4.5.0 - 14/08/2014
1 Fixed problem with prestress secondary moments for short onion dead end tendons in internal spans with transverse beams and drop panels.
2 Fixed load scales in Prestress Actions to use the same scale for all tendons.
Changes in v6.4.4.0 - 02/08/2014
1 Fixed problem with Secondary Prestress calculations for some members with tendons defined as spacing and with horizontal steps.
2 Fixed problem with stress development calculations in dead end tendons with force at end of tendon set to 0.
Changes in v6.4.3.0 - 26/06/2014
1 In the latest calculation method for prestress effects there is another inconsistency in the calculations where the prestress actions are determined assuming the tendons extend to the defined end location of the tendon, while the prestress forces are calculated assuming that the tendon force in the ineffective length of the anchorage is zero. This letest problem only affected the calculations of the secondary prestress moments for tendons with the short end span of internally stressed tendons where the profile type is a "cantilever" type. This inconsistency has been fixed in this latest release.
2 Fixed problem switching between license types for a network dongle with mixed RC and PT licenses types.
Changes in v6.4.2.0 - 30/05/2014
1 Fixed Runtime problem with 6.4.0.0 on XP computers.
2 Span Bar termination points - in some cases where extra span face reinforcement was required at supports, requiring more bars at the support than at midspan, RAPT was providing more development length than was necessary for the extra bars at the supports. This has been fixed.
3 Fixed crash for PT members to the Canadian code where no tension reinforcement exists at a cross-section for shear design.
4 Fixed problem with calculation of effective depth for Unbonded prestressed members for shear design.
5 Fixed problem with memory errors in creation of some moving load cases.
6 Fixed problem with location of flexural critical section at left support in some cases.
7 Added ACI requirement for reduced phi factors for pretensioned members in the transmission length of the strands, and extended transmission lengths in pretensioned strands with debonded ends.
8 In the latest calculation method for prestress effects there is an inconsistency in the calculations where the prestress actions are determined assuming the tendons extend to the defined end location of the tendon, while the prestress forces are calculated assuming that the tendon force in the ineffective length of the anchorage is zero. This only affected the calculations of the secondary prestress moments for tendons with anchorages terminating within the ineffective anchorage length of a support and if the anchorage was eccentric from the concrete centroid. This inconsistency has been fixed in this latest release.
Changes in v6.4.0.0 - 15/04/2014
This is a major new release of RAPT. We have made significant improvements to the calculations for prestressed concrete members. The effect of these changes is to more accurately model the effects near end anchorages of all types.
From a designers perspective, it is important that the designer model the frame and the prestress layout logically, especially at frame ends and where tendons terminate. For example, even if an end support is considered to be a pinned end connection, it is essential that the designer show the true concrete edge location, not just leave it at the support location (centreline if it is a column). This is never the true situation and it is impossible to justify according to most design standards in determining the termination requirements for reinforcement, but it is often how it is modelled for simplicity of input. Unfortunately, this induces significant conservatism into the design results as the determination of the development of the tendons and the end development of the reinforcement are dependent on knowledge of the location of the actual slab edge and the real extent of the reinforcing bars and prestressing tendons. If RAPT is given the wrong information, it will return results consistent with that information!
The major changes in this version of RAPT are in the following areas
Anchorage Properties
All aspects of the anchorage properties defined in the RAPT Materials Properties have now been implemented. RAPT now allows for
Post Tensioning Live End Anchorages -
- ineffective length - the tendon is assumed to not exist over this length for any calculations.
Post Tensioning Dead End Anchorages -
- ineffective length - the tendon is assumed to not exist over this length for any calculations
- transition length - the tendon force is assumed to increase from the start value developed at the and of the ineffective length to the end value where the anchorage section of the tendon transitions into the main tendon. This will normally be at the beginning of the duct of the tendon. This will affect the forces in the tendon after jacking and at long term.
- development length - the stress increase in the tendon due to strain compatibility under flexure is assumed to develop according to the development length rules in codes for pretensioned strands. For post tensioning anchorages, the development length is assumed to start at the end if the ineffective length and strain induced stress increases are assumed to occur in the transition length. The maximum stress possible at the start of the development length is the nominated percentage of the full design stress in the properties, unlike pretensioned strands where there is no increase in stress in the transmission length. At the end of the development length, the strand can achieve its full design strength without reduction for development.
The effects of these changes will be seen in the tendon forces, strand extensions and strength calculations. For example, the tendon force at the end of an onion type dead end anchorage after stressing will be 40% of the force that would be there for a full development type anchorage as the onion type dead end can only develop 40% of the force.
Pretensioned strand anchorage -
- ineffective length - the strand is assumed to not exist over this length for any calculations.
- transmission length - the strand force is assumed to vary from zero at the end of the strand to the force at stressing at the end of the transmission length. Over the ineffective length, this force is then set to 0, so there is a step in the force at the start of the transmission length. The force in the strand over this length is assumed to be unaffected by stress increases in strain compatibility calculations.
- Development length - the maximum stress that can be developed in a strand under strain compatibility effects is assumed to increase from zero at the start of the development length (at the end of the transmission length) to 100% at the end of the development length. This is the amount of stress increase allowed in the strand under flexural action. These are percentages of the available stress increase above the stress in the strand after stressing and losses.
The effects of these changes will be seen in the tendon forces, strand extensions and strength calculations. For example, the force at the end of a pretensioned strand will be zero.
The effects of these changes will be most noticeable in the anchorage zones of dead ends and pretensioned strands. The tendon capacity will be significantly reduced in these areas. previously designers have often stopped tendons short of their actual ends to allow for this capacity reduction. This is no longer necessary. Also, the transfer zones in pretensioned members will now more accurately reflect the reduction in force at the ends of the strands, thus reducing the transfer stresses which were previously over-estimated in RAPT.
Coupled Post-Tensioned Tendons
An option has been added into the Prestress General Grid to allow the designer to define each anchorage as being coupled or not. Previously, if 2 tendons stopped and started at the same location, they were assumed to be coupled. This logic no longer works once we allow for ineffective lengths at anchorages. There were also no checks on the logic of coupling of the tendons and to avoid RAPT considering the tendons to be coupled, the designer had to separate the anchorages.
At each anchorage, the designer can now nominate that the anchorage will be coupled. This is only available for internal anchorages and is not possible with onion type dead anchorages or pretensioned strands. In the new release, tendons stopping at the same location will no longer be considered to be coupled unless the connecting anchorages on both tendons are nominated as coupled. Otherwise, there will be assumed to be a gap between the tendons and any capacity required will be supplied by extra reinforcing bars. RAPT will carry out checks to make sure that the information for coupled tendons is acceptable. The following must be satisfied
- The total number of tendons each side of a coupler must be the same.
- the tendon type, strand type and anchorage size and number of strands must all be the same for the coupled tendons.
- the anchorage profile heights of the coupled anchorages must be the same.
- onion anchorages cannot be coupled.
If any of these conditions are not met, RAPT will give an error message and will not allow the run to continue until the data is consistent.
- It is technically possible to have Live End Anchorages either side of the coupler if a special internal stressing arrangement is used. This is not commonly available. RAPT will give a warning if this is selected for the designer to ensure that the prestressing company involved in the project can supply this coupler arrangement.
- to achieve full tendon force at a coupler, Swaged Dead Ends with a full force transfer end plate must be used. The strand must be debonded between the dead end plate and the duct to allow the full force to develop at the plate. This is the 4th anchorage type available in the RAPT anchorage list. This is not the standard coupler used in most countries, especially in building prestressing. Normally, the strand is bonded between the coupler plate and duct and a Swaged Dead End with nominal end plate type anchorage should be used in RAPT (3rd anchorage option in the anchorages list) to match the coupler details normally available. Otherwise, the designer should check with the prestressing company involved to make sure that the debonded strand length can be provided.
Prestress Moments and Shears
Previously in RAPT, all of the prestress moments and shears have been calculated from the Prestress Actions. These are based on the average prestress force in each tendon in each span. The actual force variation over a span length is normally relatively small so this has not had a large effect. However, now that RAPT is allowing for the force reductions in dead end anchorages and in transmission zones of pretensioned strands, the effect of the force variation in a strand over a span length can be very significant especially in anchorage regions.
To try to allow for the variation in the force over a span length more accurately, we have modified the calculations for the moments and shears in RAPT in the following way
- Secondary prestress effects are still based on the Prestress Actions and the average force in each span in each tendon.
- The primary prestress effect is now calculated from the actual prestress force at each design location, multiplied by the eccentricity of the tendon from the concrete centroid.
- The total prestress effect at any point is then the sum of the Primary and Secondary Prestress effects at that point.
Pretensioned Tendon Effects
Previously RAPT has treated pretensioned tendons in the same manner as any other tendon in calculating the moments and shears in the primary and secondary prestress effects. This has assumed that, if the tendon is in an indeterminate structure, then it will induce secondary reactions and secondary prestress effects. While this was technically correct as RAPT is being told that it is a prestressing tendon in an indeterminate structure, it is not physically possible to construct it in this way and to induce secondary effects from the pretensioned strands.
For a pretensioned strand to be included in an indeterminate structure, it will initially be manufactured in a stressing bed where the stressing will occur, and no secondary effects will be created. That precast member may then be included as an element in an indeterminate frame. Or it may be checked for lifting or transport lifting with lifting points at any location in the member, thus possibly creating an indeterminate member, but the prestressing has already been done and there are no secondary prestress effects induced.
We have modified the prestress calculations in RAPT in this version to assume that the pretensioned member is determinate at the time of the pre-tensioning operation and that the secondary effects are therefore zero. So
- Secondary prestress effects are zero.
- The primary prestress effect is now calculated from the actual prestress force at each design location, multiplied by the eccentricity of the tendon from the concrete centroid.
- The total prestress effect at any point is then the Primary Prestress effect at that point.
Strain Hardening of Reinforcing Steel
Previously, if a designer has selected to Limit Reinforcement Strain in Design Data Ultimate, RAPT has automatically included in the design for strain hardening of the reinforcing steel if the properties of the reinforcement defined in the RAPT Materials data file included a stress increase above yield at the peak strain point. Eurocode 2 specifically allows this and other codes indirectly may allow it.
In this version of RAPT, we have added an extra data item in Design Data for the designer to specifically request an allowance for Strain Hardening of Reinforcing steel in the flexural design of cross-sections. It is up to the designer to justify the use of Strain Hardening in a design for standards that do not specifically allow for it. This can only be selected if Steel strain is limited in the data item above this one in design Data.
Strain Hardening for prestressing steel will be included as defined in specific design standard rules independent of this data item eg AS3600 and ACI318 automatically allow for strain hardening of prestressing steel in all designs. RAPT will automatically limit the strain in these cases to the maximum defined in RAPT materials data if strain limitation is not specified as it is a logical requirement where strain hardening is allowed for in the design.
Materials Defaults
The materials defaults files for BS8110 based codes have been updated to use the Eurocode terminology for concrete strengths. While the concrete strength is still nominated in Cube Strength as the Characteristic Strength, the strength grade is now called, for example, C32/40 for 40Mpa cube strength concrete and the Characteristic Concrete Strength is set at 40MPa. RAPT will internally calculate the characteristic cylinder strength if this materials file is used with Eurocode which requires a cylinder strength for design by multiplying the Cube Strength by .8. If it is used with a Cube Strength code such as BS8110 or one of its derivatives, the cube strength will be used in all calculations.
Whenever the Design Code is changed, RAPT will automatically recalculate the concrete properties for all strength grades in the Materials data based on the new design code. At any stage, the designer can recalculate those concrete properties if they desire.
Whenever the long term concrete properties calculation method is changed, RAPT will recalculate the default shrinkage and creep factors to suit the calculation method selected. This allows the designer to use a different method than the default method for a specific design code.
Changes in v6.3.18.0 - 19/12/2013
1 Fix problem with column interaction diagrams with prestressing steel defined.
2 Fix problems with Moving UDL Loads defined in Moving Load Cases.
3 Fix step in deflection diagram in left end cantilevers in cases where the member curvature changes sign.
This is very unusual and may happen where there is a significant change in section in the cantilever with prestress included.
Changes in v6.3.17.0 - 14/10/2013
1 Fix problem with column interaction diagrams with prestressing steel defined.
2 Fix intermittent printing problem.
3 Fix InstallShield installer problem on some Windows 8 installations.
Changes in v6.3.16.0 - 23/09/2013
1 There is an error in the shear calculations for post-tensioned members in the check to determine if minimum shear reinforcement is required.
This was problem introduced in a release earlier this year. The Pv term is being included twice in the check and can result in no shear reinforcement
being required by RAPT at sections where the tendon has a significant slope, so away from the normal shear critical sections where the tendon slope
is normally very small.
2 Finally fully fix unusual M/N interaction diagram (intermittant) for some columns with circular sections.
Changes in v6.3.15.0 - 26/06/2013
1 Fixed problem with calculations requiring limitation of steel strain.
2 Fixed phi calculation for ACI318 code.
Changes in v6.3.14.0 - 13/06/2013
1 Fix problem with concrete stress strain curve in some circular column interaction diagrams.
2 Modify concrete stress strain curve properties for Cube Strength codes to better match the Eurocode model.
3 Update Codemeter Drivers to latest. It is important in network installations to ensure that the Codemeter Drivers on client and server computers are consistent.
Changes in v6.3.13.0 - 21/05/2013
1 Automatically adjust cover for reinforcing bars and prestress for fire axis distance when the item is defined or when the axis distance is modified. The user can still over-ride this value by typing in a specific cover for a particilar bar or tendon. If this copver causes the tendon to violate the axis distance limits, RAPT will give a warning but allow the design to proceed.
2 Fix unusual M/N interaction diagram intermittantly for some columns with circular sections.
3 Fix shear problem for unbonded prestress tendons.
4 Fix logic for display of pattern load deflections in some unusual cases.
5 Fixed efefctive depth logic for members with longitudinal step for codes that limit the effective depth to a minimum of .8 * D. The choice of the depth to use in this limit was unconservatively being taken as the full depth of the section even when the reinforcement was being placed below the step so that the full width was available for shear, not the reduced width of the deeper section.
Changes in v6.3.12.0 - 20/02/2013
1 Updated beam and punching shear calculations to Eurocode 2
2 Fixed problem with prestress capacity calculations when strain greater than breaking strain.
3 Fixed problem with Development length rounding error.
4 Fixed tendon profiling problem for tendon stopping exactly 50mm from the end supports.
Changes in v6.3.11.0 - 24/01/2013
1 Further improvements to shear calculations. If a shear capacity shows as 99999, there is no requirement to calculate this type of shear (either flexure shear or principal tensile shear) at this location.
Changes in v6.3.10.0 - 10/11/2012
1 Fix update notification
2 Improved Principal Tensile shear calculations for prestressed members.
Changes in v6.3.9.0 - 17/10/2012
1 Fixed shear crash problem with element above slab.
2. Fixed array memory problem for very complex moving loads.
3. Fixed P/A calculation for punching shear with tendons in the compression zone.
Changes in v6.3.8.0 - 02/10/2012
1 Further refinement of calculation of flexural reinforcement for shear (Moment offset) at contraflexure points.
2 Improvement in the display of the flexural reinforcement for shear in the Flexural Design - Ultimate graphics output. It will always show in the total area required in a span on the graphics now, but, in some cases where the contraflexure point is very close to the support, between the centre of the support and the critical section for flexure, may not actually show in the graphics diagram at the point required.
Changes in v6.3.7.0 - 10/09/2012
1 Improved calculations for termination of bars and reinforcement layout.
2 Fixed calculation of tension force available at contraflexure point for shear calculations when the point is in the development length of a bar. RAPT was previously using the force available at the next calculation point away from the contraflexure point. For normal situations this did not affect the results but in the development length, especially with small bars and short development lengths, this could often mean a much lower available force was calculated as the amount of bar development was underestimated.
Changes in v6.3.6.0 - 25/08/2012
1 Fix Australia.rmc materials default file, missing reinforcement default data.
2 Fix calculations of development lerequirements greater than 100% in some cases.
3 Fix default concrete strength setting in new files.
Changes in v6.3.5.0 - 08/08/2012
1 Fixed bug in calculation of minimum reinforcement for crack control when the tension reinforcement type is mesh. The maximum spacing limit was not being determined correctly in this case, overestimating the number of bars required.
2 Improved crack width calculations for AS3600-2009 for PT members to allow variation only in bar diameter in controlling crack width. Bar spacing is automatically set to 300mm and only bar diameter can control the design.
3 Added option for Eurocode 2 crack control provisions to give the designer control over the crack width. Options are default (.3mm for RC sections and .2mm for PT sections) or user selectable .2, .3 or .4mm crack width.
4 Added data checking for incomplete user materials data definition.
5 Added limitations to straight lengths in tendon profiles at the ends of cantilevers. This has never been allowed but was not blocked by the data checking.
6 Modified data checking for prestress cover and axis distance so that all spans are checked automatically. Previously, if an error was found in one span, no checking was done on spans to the right of that span until the offending profiles in that span were fixed.
7 Modified the axis distance limitation for prestressed tendons to nominated axis distance + 15mm (previously 10mm) in accordance with Eurocode 2 and a soon to be released amendment to AS3600.
Changes in v6.3.4.0 - 26/06/2012
1 Fixed bug with depth of top reinforcement in reinforcement layout.
2 Fixed bug with tension force available for shear for designs to AS3600 pre 2009 and where the section is non ductile.
Changes in v6.3.4.0 - 22/06/2012
1 Modified Concrete strength data so that it automatically sets an equivalent concrete strength when the Default Materials set is changed.
2 Modified default time of loading for Columns to 28 days.
3 Modified Creep maturity factor for AS3600 to the new equation in the coming AS3600 amendment.
4 Made further improvements to the calculations for D offset requirements of codes to fix some problems and improve the logic in some areas.
5 Added calculation for the flexural reinforcement requirements for shear at the points of contraflexure for support moment contraflexure points. Previously this was only calculated for span moment calculation points.
6 Include the flexural reinforcement requirements for shear at the points of contraflexure in the graphics for Flexure - Ultimate - Reinforcement. If this occurs at a calculation point 9unlikely), the requirements are compared to the flexural design values and the controlling values reported.
If the contraflexure points occur away from calculations points, extra points are included in the graphics with values for Total reinforcement and Shear reinforcement only.
In a normal span there could be up to 4 contraflexure points.
7 Included flexural reinforcement requirements for shear at the points of contraflexure for support moments into the Reinforcement detailing to determine the final reinforcement layout.
8 Modified the logic for determination of minimum reinforcement requirements for crack control to give the designer more control. The calculations will now use the Minimum Bar Size for that design zone at the maximum spacing nominated in the Reinforcement Details screen. The designer can manipulate these items to control the minimum area of reinforcement as the only requirement is a spacing limitation for crack control.
Also fixed some inconsistencioes in these calculations to ensure that the reinforcement added conforms to maximum spacing rules for crack control.
9 Added Canadian Standard A23-3 (not including special earthquake design rules. These will be added later this year).
Changes in v6.3.3.0 - 09/02/2012
1 Fixed problems with changing reinforcing types and carbon fibre.
2 Fixed problem in deflection calculations introduced in 6.3.2.0. Deflections were being severely overestimated in some cases.
Changes in v6.3.2.0 - 20/12/2011
1 When the Bar Type in Reinforcement-General input is modified, any user defined bars that are of the same type are modified to the new type and the closest equivalent bar size to the original is selected. The data in the User Defined reinforcement screen was not being modified to reflect this, though the changed data was used for design. This has been fixed.
2 In Slenderness calculations for columns, the modifications to clause 10.3.1(a) in AS3600-2009 were missed in the 6.3.1.0 release. This has been rectified.
3 In the Slenderness calculations for columns, creep is very dependant on the time of loading. RAPT has always defaulted this to 10 days, the same as for floor slabs. This is not logical for columns. This did not have a large effect for design to AS3600-2001, but the changes to the maturity Coefficient in AS3600-2009 have resulted in a large increase in the creep co-efficient for early loading. The default has been changed to 28 days. The designer should adjust tjhis to an appropriate value for the column being designed.
4 Calculations for tension zone in column interaction diagrams modified to remove the "kink" that sometimes occurs in the interaction diagram in the direct tension area.
5 Fixed intermittant crash in flat slabs with steps and drop panels.
6 Fixed inconsistency in deflection calculations for lightly stressed members when shrinkage value are adjusted. This was related to the section properties used to determine the cracked condition of a section. Inconsistent velues were being used for the permanent load combination for short term and long term concrete properties.
7 Modified Moment Redistribution to redistribute each individual pattern live load combination in the direction nominated. This results in the support moment only being reduced for positive redistribution until the positive moment reaches the maximum level. Then positive moments are also redistributed if more redistribution than is required to achieve this is requested.
This logic only works when the envelope of effects is from automatic patterning of the live load case. Redistribution for alternate live load cases, moving load cases and envelopes still redistributes the entire envelope.
Changes in v6.3.1.0 - 2/10/2011
1 Added AS3600-2009 code changes. This includes major changes related to
- concrete properties (maximum concrete strength is increased to 100Mpa and a new compression block defined with special ductility requirements for high strength concretes, concrete modulus has been reduced significantly and mean concrete strength defined and creep and shrinkage rules have been modified),
- flexure and shear design relating to the changes to the bending Moment D offset rule - all design codes
- development lengths
- crack control
- ductility rules
- capacity reduction factors
- plus many other changes
2 New concrete stress/strain curve based on Eurocode 2 curve used for all design codes to better model the lower ductility of high strength concrete.
3 New implementation of the Offset of the bending moment diagram rule for all design codes to better match the logic required for both RC and PT design. The simply Moment Offset required in most codes does not apply to PT members and we have used the Required Tension Force logic of Eurocode 2 for all design codes.
4 Addition of Designer Comments to the output report.
5 Full compatibility with Windows 7 interface changes
Changes in v6.2.2.2 - 2/11/2010
1 Added Maximum Shear Force to shear text output at each design location.
2 Added .5 * Vuc line to shear output graphics to show the standard code limit for beams.
3 Added an option into Design Data Ultimate to allow the designer to change the critical shear design location from the Code Default to the Face of the Support. When this is selected, Shear Enhancement (2v/a) is not included. To include Shear Enhancement at Supports, select that option in Design data Ultimate. It will automatically include the shift of the critical shear design location to the face of the support.
4 The option to set concrete shear capacity, Vuc, to a reduced value in Design Data - Earthquake had never been implemented. It has now been implemented after discussions with the AS3600 code committee as to how it should work.
5 When beam shear is checked at the critical section at d from the column face (Shear Enhancement 2a/v not requested), RAPT previously has not checked maximum shear at the face of the support. This has been general industry practice except for BS8110 based design codes. On discussion with concrete design acedemics, we have now added a check for the maximum shear at the face of the support, even if the shear critical section is nominated at d from the face of the support. Checks on Vuc are still only made up to the nominated critical section.
Changes in v6.2.2.1 - 07/10/2010
1 Fixed problems with vertical steps in top surface of slabs with Fielders metal Decking.
2 Fixed problem with calculation of reinforcement layout (illegal operation).
3 Added functionality to Codemeter Dongles to allow sharing of RC and RC + PT licenses on one dongle.
4 ACI Clause 10.10.1, limit of 40 added to L/R limit for ACI code slenderness calculations.
5 When Alternate LL cases are combined with a Patterned main LL case in a flat slab (two way action), the moment envelopes for the middle strip are ignoring the Alternate LL cases. This has been fixed.
Changes in v6.2.2.0 - 26/7/2010
1 Fix problem with section rotation for quadrants of circles.
2 Fix problem with Extend Radius when converting to trapeziums.
3 Fix problem with varying Prestress force values in tendons of the same type in prestressed columns.
4 Fixed crash in Reinforcement Layout development calculations fort ACI318 code.
Changes in v6.2.2.0 - 8/7/2010
1 Fixed Loads Input screen refresh when load definition changes
2 Fixed problem with development lengths for Mesh reinforcement to AS3600
3 Fixed problem with determination of top reinforcement in some cases with top reinforcement only at midspan.
4 Improved Reinforcement Layout for bottom reinforcement with reinforcement only required at span ens and not at the maximum moment area. Previously RAPT only considered extra bars at ends in cases where the extra reinforcement was only required outside the points of contraflexure, so only for ductility reinforcement at supports. RAPT now looks for any increase in reinforcement outside the middle third of the span to determine if extra end bars should be considered.
Changes in v6.2.1.9 - 18/5/2010
1 Added input data warning to check on minimum cover related to bar size. If the cover supplied is less than the bar diameter, RAPT will warn the user but allow the calculations to proceed based on the defined cover.
2 Related to 1 above, when calculating required bar size and the preferred bar size does not work, RAPT will adjust the cover for larger bars if the larger bar reduces the cover to less than the bar diameter.
3 In cases where a section has ultimate capacity, but the tension reinforcement is in the compression zone, there is no effective depth according to normal design rules. In this case, RAPT adds minimum reinforcement at the tension face. This area of reinforcement is now based on the cracking moment of the section without PT, so as an RC member.
4 In Column Design for circular columns, added a switch to allow the designer to locate the position of the top bars in the column.
5 In Column Design, added a toolbar icon to acces Design Points directly, rather than through the Control Tree Structure.
6 Modified the opening of the Loads Input Screen so that the Panel Loads option is always the default load screen when the Load Cases screen is first created.
7 In Column Design, the designer can now define any column rotation between 0 and 360 degrees (the column is rotated clockwise) for the rotation of the column about which the calculations are carried out. The pale green line on the output graphics shows the axis about which bending occurs. This rotation defines the angle of the neutral axis, not the direction of the moment resultant. In general, it does not give a Biaxial column interaction diagram as a result.
8 Design routines for the inclusion of Metal Decking as a structural reinforcing material have been added. For Australian materials specifications, the Metal Decking must be Fielders decking. All Fielders Decking types have been added to the Australia Materials file. Designers should check with Fielders in each State to make sure that a specific sheet type and thickness is available in that StaTe.
9 Bug fixed in time dependent shrinkage calculations for Eurocode 2.
10 Fixed bug in load combinations when a load case is changed to earthquake or Wind from another type. Factors is non-earthquake and wind cases for the earthquake and wind loads are now set to 0.
Changes in V6.2.1.8 - 14/9/09
1 Fixed problem with crack control calculations to BS8110. One check was still being done even if crack control checking was not requested. Some crack control reinforcement was being reported as Ultimate Strength Reinforcement as well.
2 Fixed reporting of servicability reinforcement to BS8110.
3 In Input Dialog, added option for the definition of Initial Superimposed Dead Loads and Extra Superimposed Dead Loads.
4 In Input Dialog, added option for the definition of the fixity of the bases of the columns below, Pinned/Fixed.
5 Automatic Update available announcement now produces a temporary popup tooltip at the bottom right corner of the screen. The check for availability of an upgrade is done 1 minute after the RAPT session commences.
6 Modified Data Check for the length of the load pattern for Moving Load cases where the load extent has been limited at one end only to allow load patterns to extend past the end of the frame at the unlimited end. Actual moving load calculation results were not affected.
Changes in V6.2.1.7 - 28/8/09
1 Fixed calculation of effective with for shear for circular elements.
2 Added user controlled data variable for Capacity Reduction Factor for Compression for column design. Previously this was hard coded into RAPT, but some column details require different values relative to the Capacity Reduction factor for Tension.
3 Fixed problem with Superimposed Dead Loads in the New Frame Dialog not creating a corresponding load case in the input.
4 Modified shear Bv calculations in complex section shapes to ignore the flange width.
5 Fixed shear Bv calculations for External beams.
6 Automatic Update available announcement is now a world symbol at the bottom right of the status bar. We will try to make this more obvious in the furure with a temporary popup tooltip.
Changes in V6.2.1.6 - 06/08/09
1 Fixed crash in shear design to ACI code when no extra reinforcement required.
2 Modified Loads Data Checking to stop Other Load Cases to be defined as Moving Loads. Only LL and Alternate Live Load cases can be run as Moving Loads.
3 Fixed output of tendon profile values to printer for multiple profiles.
4 Fixed problem with effective depth in shear calculations where reinfocement set down for void elements.
5 Fixed problem with Moment Redistribution being blocked for frame without column supports defined. Note, RAPT will only allow moment redistribution for a Braced Frame!
6 Added an input error in 2way beam designs to prohibit cases where the column strip width is less than the beam width.
Changes in V6.2.1.5 - 27/02/09
1 Fixed Windows resource overload with auto repeat function.
2 Fixed output of tendon profile values to printer.
3 Fixed anchorage size problem on tendon profile output to printer.
4 Fixed text output of moving load input.
5 Fixed listing of number of bars in column output when a combination of bundled and single bars is used in a circular column.
Changes in V6.2.1.4 - 27/02/09
1 Fixed problem with pattern loads to BS8110 if no loads are defined in the Self Weight Load Case.
2 Fixed problems with determination of bar development where 2 bars meet at midpsan.
3 Fixed problems with pretensioned wire in design.
4 Fixed problems where RAPT results give no reinforceemnt at the tension face while the shear design has a moment at that face.
5 Added option to create a DXF file for the prestress profiles. Right Click in the Input Prestress Graphics view to select the option to create a DXF file. A doalog will be presented allowing the definition of the format required.
6 Added design option for carbon Fibre strips as reinforcement. This option allows the designer to define the load condition at which the strips are attached. Carbon Fibre is added as User defined Reinforcement. properties can be defined in the materials data.
7 Added output option for calculations at the Permanent Service Load condition.
8 In material data, added automatic recalculation of Concrete Modulus when the concrete density is modified.
9 Fix problem with minimum reinforcement for one way slabs to TR43.
10 Fix problem with selection of Alternate LL cases in some cases.
11 Fixed problem with end termination of bars to BS8110 and variants of this code.
12. If a calculated bar requires development, RAPT will define the exact % of development required and report this in the output. Normally in detailing, a designer would then provide this as either 50% or 100% developemnt using either a standard bend, special bend or a lap splice.
When this reinforcement is inserted into the design as User defined reinforcement, RAPT will still nominate the calculated % of development unless it is less than 10%. If less than 10%, RAPT will round it up to 10%. If less than 10% development is specified for a bar, RAPT assumes that there is no development at that end of that bar in the calculations.
13 Fix problem with updating of reinforcement cover when user defined bar locations modified.
Changes in V6.2.1.3 - 01/08/08
1 Fixed problem with backup file naming when multiple sessions of RAPT are run on the same computer.
2 Fixed problems with detailing of reinforcement from some complicated reinforcement arrangements. Detailing of reinforcement has been improved in some areas, especially where compression reinforcement is needed, resulting in shorter bars being defined in some cases by RAPT.
3 Improved routines for determining plastic hinge locations, especially in zones where there is a change in section.
4 Added logic for repositioning of point loads and point moments on cantilevers when the cantilever length changes. Now,
- If the point load is at the free end of the cantilever, it will remain at the free end no matter what changes are made to the cantilever length.
- If the cantilever length increases, the distance to the point load from the free edge will be maintained.
- If the cantilever length reduces, the length to the point load from the support end will be maintained until the load reaches the end of the cantilever at which time it will remain at the end of the cantilever as the cantilever is shortened further.
- For loads with a length, if the cantilever length reduces to a point where the point load length is longer than the cantilever, the length will be reduced to zero and the load placed at the end of the cantilever.
5 An option to check for RAPT Updates has been added. This can be controlled by the user from the View->User Preferences Dialog. An extra Tab page has been added giving the user the option to nominate for
- Automatic Check - This will be done whenever a new RAPT session is launched.
- Manual check by clicking on the button.
In either case, RAPT will then offer a button to allow for an update to be downloaded if the version on our website is newer than the current version being used.
6 Fixed problem with multiple Area Loads in moving load cases.
7 Fixed problem with loads that start or end within .5mm of a support and not exactly at the support.
8 Fixed problems with effective depth for drop caps in punching shear.
9 Added check on building type for patterning of live loads for permanent load combination for deflections. When storage building is selected, this is automatically turned on now.
10 Added data check to ensure that all load cases are included in at least one load combination.
11 Added data check to ensure that each load case has a non-zero moment value at at least one location.
12 Modified warnings for ductility for cantilevers and setting of maximum compression reinforcement at ends of cantilevers.
13 Fix problem with punching shear calculations for external panels at the drop face.
14 Add ACI 318 - 2005 changes.
15 Add warnings for serviceability limits for two way average prestress design based on ACI code or TR43 version 1 and version 2, whichever is applicable.
16 Fix treatment of cover for user defined reinforcing bars with staggered ends.
Changes in V6.2.1.2 - 25/4/08
1 Fix development length calculations for Indian Code
2 Fix covers to bars in output reinforcement layout at changes in concrete section. Rounding of bar ends no longer done at these locations.
3 Fix user defined reinforcement definition for concrete faces with steps.
4 Fix Pattern Load resetting when spans deleted/added and the total number of spans changed to or from 1.
5 Fix incorrect reporting of the prestress moment at the right end of the span in the Secondary Forces Report.
6 Fix treatment of cover for user defined Mesh reinforcement.
Changes in V6.2.1.1 - 8/3/08
1 Fix display of user defined reinforcement in output reinforcement layout graphics.
2 Fix bug in calculation of shrinkage and temperature reinforcement where user defined reinforcement is created from program calculated reinforcement.
This reinforcement was being ignored in the calculation of the shrinkage and temperature reinforcement in some cases.
3 Fix shading of some complicated column shapes in interaction diagram output.
Changes in V6.2.1.0 - 13/2/08
1 Fixed bug with depths to user defined reinforcement where there is a step in the concrete surface that the cover is being measured from. Remember, in defining user defined reinforcing bars, the controlling depths to the reinforcement are the covers at the extreme ends of the bars.
2 Fixed bug in moving load analysis where the load spacing is very small.
Changes in V6.2.0.9 - 23/11/07
1 Add extra toolbar icon in Bending Moment/Shear reports to allow each individual Moment/Shear diagram to be drawn at it's own scale rather than at the scale of the controlling diagrams. For slabs with column/middle strip results, both strips are drawn to the same scale for the diagrams in view.
2 Modified reinforcement Depth to reinforcement cover. This applies to
- design zones, where the cover is measured to the surface of the preferred bar size from the relevant input face, and
- user defined reinforcement, where the cover is measured to the surface of the defined bar from the relevant input face.
For beams, the cover is to the main bar, not the ties.
RAPT will give a warning if the calculated bar size is not equal to the preferred bar size in the final results.
If the calculated bar size is greater than the preferred bar size, RAPT will automatically adjust the reinforcement area required in calculating the final Reinforcement Layout to allow for an increased area of reinforcement based on maintaining the same cover to the larger bar, thus reducing the effective depth. The area of reinforcement is adjusted by the ratio of the effective depths.
3 When the reinforcement cover is modified in the General Screen, any bar with the same cover will now be changed to the new cover. Previously only the covers for design zones were modified.
4 Fixed bug which resulted in and endless loop in the calculations and a resulting Windows Out of Memory error. The problem was caused by a comparison of numbers and the old float rounding error in computers in the calculation of some complex section shapes.
5 Modified the reprofiling of tendons when the tendon size is changed. Now
- if the tendon is profiled to cover to a surface RAPT will reprofile to maintain cover at that face for the new tendon size
- if the tendon is going to violate cover at a surface, RAPT will reprofile to maintain cover at that face for the new tendon size
- otherwise will leave the centroid of the strand at the same height, adjusting the underside of duct height to maintain this centroid height.
6 Fixed problem with point loads with a length defined where the frame length is modified and the defined location of the point load is still on the frame but the end of the point load is off the frame. The following now occurs
- If the point load defined location is passed the end of the frame, the point load is deleted as previously
- Otherwise, the load length is shortened so that the full length of the load remains on the frame. The full point load is then applied over a shorter length.
Changes in V6.2.0.8 - 23/10/07
1 Fixed shear error calculation for members with circular voids.
2 Fixed calculations for case where a point load with a length is applied completely within the Right End of a frame.
3 Added warning if Left End or Right End dimension is large, questioning whether it should be called a cantilever. The warning is given if the distance to the edge past the column face is greater than .1 of the back span.
4 Modified the calculation method for moving loads to give a better envelope of the effects for cases where there are relatively large gaps between the loads on relatively short spans. The default number of spaces per span has been increased to 20.
5 Fixed the calculation for fixed load patterns in moving load cases when the Live Load case is defined as a moving load case.
6 Added an option in moving load cases to limit the length of the frame over which the moving load pattern is to be applied. The designer can define limits at the left and right ends of the member.
7 Modified bar size selection method if the preferred bar size does not suit the required spacing. RAPT will now select
- for beams - the nearest bar size larger than the preferred bar size that suits the spacings. If no larger bar sizes suit, then the nearest bar size smaller than the preferred bar size that suits the spacings.
- for slabs - the nearest bar size smaller than the preferred bar size that suits the spacings. If no smaller bar sizes suit, then the nearest bar size larger than the preferred bar size that suits the spacings.
8 Fixed strip width calculations and tendon profiling in middle strips for members where a right cantilever is added.
9 Fixed problems with adjustment of the ends of loads etc where the LE/RE dimension has been set to a negative value and then a cantilever is defined, an end span added or the LE/RE dimension is changed to a positive value.
Changes in V6.2.0.7 - 30/8/07
1 For old column files, fixed input to convert the concrete data to the new format. This was already happening for old frame files in the last release but had been missed for column files.
2 Modified reinforcing bar number calculations for the situation where the preferred bar size and the code maximum bar size are both the smallest bar size available. Previously RAPT was still applying the maximum bar spacing limit from AS3600 and Eurocode 2 for these 2 cases when the bar size condition was the only one necessary. This often resulted in a warning about the bar size selected.
3 In Point Load input dialog (not moving loads) fixed data check to allow a load length of 0.
4 In Point Loads (not moving loads), fixed deleting of loads with a length > 0. Previously the loads were deleting from the data grid but were remembered internally and still applied to the load case for analysis.
5 Problem (crash when bars selected) with line reinforcement in Column Design fixed.
6 In the latest version if a mixture of point loads is defined with and without load lengths, there are some cases where loads are ignored. If a load with a length is defined before a load with no length the load with no length may be ignored. This has been fixed in this release.
Changes in V6.2.0.6 - 31/7/07
1 Added Moving Loads as an option for loading. The load case used must have a Load Type of either Live Load or Alternate Live Load. It cannot be the case selected as the Live Load Case For deflections as it produces an envelope of moments. Moving Load is then a 4th option for the Load Definition. Once this is selected, the tab options available in the lower loads window will then allow the definition of a moving load pattern combined with a fixed load pattern. The moving load pattern is positioned at the left end of the frame and will be moved automatically along the member to produce the worst possible moment controlled and shear controlled envelopes using the requirements defined in the "Details" tab to control the movement.
2 The concrete properties have been modified to allow the definition of different Concrete Modulii for service and ultimate strength conditions. This was handled internally previously by RAPT in cases where it was necessary. The option for the definition of a peak strain point has been removed. The peak strain point is now calculated internally as the point at which a parabola, whose properties are determined by the relative Concrete Modulus, reaches zero slope. For existing runs, RAPT will automatically update the materials file with the new data.
If, during installation, a user decides not to update the materials defaults files from the installation program, the files will have to be manually updated by opening the relevant materials file and using the Recalculate Icon in the toolbar for the Concrete Properties to update the concrete data. Warnings will be given if a run is created with incorrect data.
For existing runs, RAPT will automatically update the concrete data when the file is reopened.
3 Added final Hong Kong CP2004 code amendments.
4 Updated the Help file and the manual PDF file to include the changes to the data above.
5 Fixed shear problem associated with partial loading for shear. If the shear results produced a shear design requirement with a moment on a member face where there was no ultimate design moment, No reinforcement was supplied at the tension face for this case so shear normally failed. RAPT will now design for the ultimate design moment for the shear case at that tension face to ensure reinforcement is supplied and make the shear results more logical.
6 Added Windows Vista support. For Windows Vista, the older versions of RAPT will not run. Both new drivers and the latest version of RAPT are required.
Changes in V6.2.0.5
1. Added check for the curvature of the main parabolic curve for double parabola type curves in the end span of a tendon where there is no reverse curve requested. Previously no check was done in this case.
2. Fixed delete of reinforcing bars in Column Design Input. Previously, when 2 reinforcing types were selected in the data window at the top right of the screen, selecting one of the reinforcing types and pressing the delete key resulted in both reinforcing types being deleted.
3. Added Column Grid References to output tables of column actions.
4. Fixed crash in latest version when steps screen accessed.
5 Modified critical section locations for shear calculations when the code critical section at each end of a span will overlap (deep beams). RAPT will now calculate shear between the critical flexural sections in this case.
6. Fixed problem with Auto Backup (and changed name to Backup rather than autosave as the backup goes into a different file with a name filename.~rpf and does not over-write the main data file).
7. RAPT now has an option for adding reinforcement for minimum reinforcement according to TR43 rules for slabs. These rules will be based on TR43 Version 1 for all codes except Eurocode 2 for which they will be based on TR43 Version 2. These rules would normally be used for Eurocode 2 (UK) and BS8110 and codes derived from BS8110. They are not set as the default setting for these codes as TR43 is not actually part of any code nor is it directly referred to by any design code.
A designer may set the Code Defaults option for this to TR43 if desired or may change it to TR43 from Default in Design Data for a particular run.
8. Modified default reinforcement layout calculations so that
- default bar size for beams is the preferred bar size
- default bar size for slabs is the smaller of the preferred bar size and the calculated maximum bar size
- if the solution above does not work RAPT will then select
- for beams the largest bar size that works within the spacing limits
- for slabs the smallest bar size that works within the spacing limits
9. Added checks for basic shrinkage strain values for different codes and calculation methods. Some calculation methods calculate the basic shrinkage by a formula so RAPT does not have a predefined value in the Materials data for those.
10. Added Hong Kong CP2004 code amendments.
Changes in V6.2.0.4 - 15/3/2007
1. Fixed problem with transfer beams at first internal column with cantilever at the column, cantilevers without back spans and modified slab thickness in cantilevers. These problems were introduced in V6.2.0.4.
2. Fixed problem with report generation for strands stopping along the length of the tendon causing a crash.
3. Added a check on the defined shrinkage for the concrete for all codes except Eurocode 2.
For Eurocode 2, the shrinkage is calculated internally by RAPT using the code formulae. Therefore the shrinkage in the European Materials in RAPT is set to 0. If this materials set is used with any other design code in RAPT, the designer needs to define a shrinkage strain or change the prestress losses basis in design Data->Crack Control to Eurocode 2 so that the Eurocode 2 formulae are used for all shrinkage and creep calculations. Any defined value of concrete shrinkage is ignored when Eurocode 2 calculation methods are requested.
For all other codes, the basic shrinkage strain (test value) must be defined. RAPT will give a warning if the value is less than 300 micro-strain and an error if it is less than 50 micro-strain. Reasonable values for this would normally be in the range of 600 to 1500 micro-strain depending on the materials used in making the concrete and the mix design. Values less than 450 are hard to achieve even with the latest admixtures and the best aggregates and mix design.
4. Fixed Design comment for transfer stress limit. The limit value was reporting incorrectly in the design comment. The correct value was used in the calculations.
5 When checking ductility RAPT will check the value of effective depth first. If it is relatively small (less than .3D) RAPT attempts to put in tension reinforcement to achieve a ductile section by increasing the effective depth. Sometimes this has resulted in large areas of tension reinforcement to save a small area of compression reinforcement. RAPT now limits this area of reinforcement to the area that would be required for ultimate strength at that face ignoring the tendons that are causing the low effective depth. If a greater area would be needed, RAPT will revert to a standard double reinforcing design at that cross-section.
6 In the Flexural design - Ultimate - Graphics output view, we have added points on the graph showing the sections RAPT considers to be the Critical Plastic Hinge locations and the final depth of neutral axis ratio at these points.
7 When the total number of spans, including cantilevers is 1, pattern load is now turned off automatically.
Changes in V6.2.0.4 - 17/1/2007
1. Fixed problems with the automatic deleting ~backup files when a run is closed or directories change. The user will now be asked if they want to reload a backup file rather than it being loaded automatically if it exists in all cases, instead of only when there are multiple backup files available as previously was the case. The option is also available to delete the backup file.
2. Added more pattern loading options. Pattern Loading will always be turned on by default. In the General Screen, the user can turn off Pattern Loading with a Y/N option. This will turn off all pattern loading options described below. As well as patterning live load for ultimate strength and crack control design, RAPT will now create odd spans loaded and even spans loaded pattern deflection cases. A "Pattern Live Load " data screen has been added under Design data to allow the designer to select which pattern load options to use in a design. In it the designer can choose the following
- Pattern Live Load factor #.##
- Pattern Live Loads for Ultimate Limit State Design Y/N
- Pattern Live Loads for Crack Control Design Y/N
- Pattern Live Loads for Deflection Design Y/N
- Pattern Live Loads for Permanent Deflection Load Case Y/N
For normal buildings where the live load pattern is completely random, patterning of the live loads should be required for the short-term load effects on deflection but not for the permanent load effects. This is the default setting in RAPT. For cases where there is a known pattern of live load on alternate spans as may happen in some storage situations, libraries etc, patterning of permanent live load may be logical. It is up to the designer to decide on this requirement.
3. Fixed problem with copy/pasting of self weight loads for panel load cases.
4. Fixed problem with determination of flexural critical section location where transverse beams are present in slabs for BS8110 and derivative codes. The transverse beam was being ignored if it extended past the column face.
5. Modified routines allowing for the effect of sloping soffits on low point tendon profiling to only allow for slopes in the area of the low point in a span. It should be noted that where a sloping or stepped soffit occurs in a span, RAPT will not always be able to profile exactly to the minimum cover specified. In some cases the designer may have to override RAPT's calculated low points to increase or reduce the cover supplied. If an increase in cover is required, RAPT will give a warning when output calculations are asked for or when the designer requests a data check.
6. Added partial patterning of live loads for ultimate shear strength analysis. The live load shear at a section will vary depending on how much of the live loads is actually applied at one time. The maximum shear at a point could be caused by only part of a UDL being applied or by one of a group of point loads being applied depending on the position of the loads applied and the cross-section in question. This check is required by AS3600 which requires a default criterion setting the minimum live load shear to 25% of the maximum live load shear in that span (zero is not allowed at the maximum positive moment point) and is logically required in all design codes to satisfy the true conditions that occur with loadings in buildings and bridges. RAPT now automatically analyses for partial application of live loads for ultimate shear. Point loads are assumed to be applied individually and UDL's are applied for various lengths of each span in order to calculate an envelope of live load shears for combination with the other load cases. The nominal AS3600 figure of 25% is not used in RAPT. This is done automatically for all Live Load and Alternate Live Load cases in RAPT.
7. Fixed problems with multistrand prestressing tendons in Column design module.
Changes in V6.2.0.3 - 24/10/2006
1 Fixed problem in Beam Shear Calculations for Hong Kong Code
2 Fixed problem in Punching Shear Calculations for BS8110, CP65, Hong Kong Code, SABS0100 clause 3.7.7.5 limiting punching shear capacity to 2 * vc.
3 Modified all materials data files to improve data for .6" strand tendons and dead end properties.
4 Added AutoBackup option. This can be turned on in View - User Preferences - User Options. Tick the box and set a time interval. A copy of the file will be created using filename.~###. When RAPT is closed or the file is closed normally, the backup file will be deleted automatically so that the only backup files on your computer when RAPT is not running should be the one that exists if there is an illegal operation and RAPT closes down prematurely. When RAPT is restarted, the user will immediately be prompted with a dialog asking if RAPT should open the backup file if one exists.
5 Fixed problem with adjusting drop panel lengths when span length changes
6 Fixed problem with Formatting of Beam Shear Info Dialog in cases where maximum Shear value never shows on the shear graphics.
7 Fixed problem with resetting of prestress drape lengths when LE and RE lengths are modified using Alt Repeat.
8 Fixed problem with the calculation of the Exposed perimeter for Theoretical Thickness calculations in cases where voids are placed in the edge of the concrete.
9 Fixed operation of horizontal steps for
"Step Sides of a Layer" - Step In/Out option fixed.
"Step Corners of Layers" - Sides option removed and Step In/Out option fixed.
10 Grid reference logic revised for cases where the user has not modified the grid references and spans at the left end are deleted. In this situation where the grid references and Column numbers are equal and start at 1, the modified values will always reset to start at 1 when left end spans are deleted.
11 Fixed incorrect resetting of Column/Middle strip in reinforcement data on undo. previously, the middle strip data could be showing while the header said column strip after an undo.
Changes in V6.2.0.2 - 30/9/2006
1 Modified Tension Stiffening calculations by Modified Concrete Tensile Modulus method to reflect the changes suggested in Technical Note 372 and Technical Report TR59. Instead of a constant amount of tension stiffening, the amount of stiffening provided is now related to the concrete strength and the tensile strain in the extreme tension face of the member. This results in reduced deflections at the onset of cracking.
2 Modified the prestress tendon profile graphics to only show tendon profiles that have a number of tendons or a tendon spacing defined. Previously the profile shape showed on the graphics even if there were no tendons defined for that profile.
3 Modified BS8110 crack width calculations to add extra reinforcement for crack control if the requested level of crack control cannot be provided with the reinforcement required for ultimate strength. Previously in this case RAPT reported a negative maximum reinforcement spacing. This will still not guarantee that a reinforcing bar number/size solution can be found for this design.
Once the next AS3600 release is finalised later this year, the same approach to crack control calculations will be offered for AS3600 and Eurocode 2 where the designer will be able to nominate a crack width limit and RAPT will nominate maximum bar size and spacing requirements for that crack width.
4 Fixed problem with rounding of the end location of reinforcing bars.
5 Fixed problems with copy/paste of elements.
6 Add Indian Concrete Codes IS 456 and IS 1343 as code design options and Indian materials data.
Changes in V6.2.0.1 - 16/8/2006
1 Fixed problems with saving mesh data for columns
2 Added edit view field on task bar. When editing data in RAPT the data being edited and the current cursor position in the data is shown at the bottom left of the task bar. This is useful when the data string being edited is longer than the current data cell size as the full data string is shown on the task bar while only an abbreviated length of the data string is shown in the data cell until the edit operation is completed.
3 Added distances to left and right column from the current cursor position in the task bar for main graphics view. When a point is selected with the cursor in the graphics view, the location from the left end of the frame is shown in the edit cell in the toolbar. At the same time, the distances to the support lines to the left and right of the selected point are now shown at the left end of the task bar.
4 Modified the prestress calculations to allow the designer to define a zero prestressing force. This allows the checking of a design where the tendons have not been stressed for some reason. If the tendons have not been grouted, the unbonded prestress option should also be selected.
5 Modified the loading type information in the materials data to include assembly (crowd) loads, heavy vehicle parking, wind and snow loads. Default Combination factors can now be defined for these load types.
6 Default load combinations have been modified to include the effects of the changes in 5 above as well as the latest versions of ACI318 and Eurocode 2. As no other codes currently define the serviceability load combinations we have created default cases based on the logic in Eurocode 2 (this is the proposed method in the new AS3600 also). Default combinations have also now been included for snow loads.
7 Added routines to round off the length of program calculated reinforcing bars. Bar extents are rounded to the next nearest 50mm or 2" and allow for bars meeting at a point with the rounding done towards the bar type which has the smaller total area of bar.
8 Fixed program crash when cell repeat function is used where there is a Data list in the cell in the next row. This happened in drop panels as well as some other screens.
9 Fixed apparent program crash when defining some element shapes. RAPT was going into an infinite loop if the element shape exactly matched the dimensions of an existing shape such as a down turned beam.
10 Fixed all other reported interface bugs.
11 Fixed problems with shear design to Eurocode 2. Note the shear design method in RAPT for Eurocode 2 is from an old version of the code. We are currently revising this and hope to have the new version in the next RAPT update. The changes are significant and the effects wide ranging with concrete shear capacity now being ignored once the applied shear is greater than the concrete capacity in the new version of the code.
12 Fixed some inconsistencies in reinforcement detailing. Also fixed error (over-estimate) in the calculation of the development length of bars in the detailing section (not in design calculations) in some concrete configurations.
13 Modified logic in prestress input to automatically update the tendon profiles to maintain the same cover when tendon size or prestress type is modified.
14 Added extra calculation points in negative moment regions to better define the steep moment gradient in this area and improve bar termination calculations.
15 Modified method of determining low point profile heights for skewed parabolic profiles to better estimate the effect of the skew in the internal iterations to determine the required mid parabola length centreline profile heights to achieve nominated covers.
16 Modified resetting of reverse curve radii when tendon types and sizes change to revert back to the default radius if the previous radius was equal to the previous minimum radius and the new minimum radius is less than the default radius. Previously, the radius only changed when the new minimum radius was larger than the current radius.
17 Added lateral Distribution Factors to output report for 2way frames.
Changes in V6.1.2.8 - 17/5/2006
1 Fixed problems with Column Grid References. Previously, when adding or deleting spans the grip references were sometimes incorrectly renamed when trying to fit to a pattern. This could then cause items whose locations were referenced from that column to move if multiple columns ended up with the same grid Reference name.
2 Add Hong Code CP2004 as a new design code option. This is being released as a Beta version for this code while 3rd party checks are carried out.
3 Added an option for complex effective flange width for beams. The complex version uses the Eurocode 2/Hong Kong CP2004 logic of different effective flange widths in the negative and positive moment areas by default.
4 Added CEP-FIP 1970 and CEB-FIP-1978 creep and shrinkage calculation methods as options.
5 Fix problem with calculation of development lengths for bottom reinforcing bars. The development lengths will now be shorter.
6 Added extra functionality for creating complex column shapes. The main options allows the designer to
a) define any shape or group of shapes eg a circle, and then make a cut through the shape to leave only the part of the shape on one side of the cut.
b) convert circular shapes to multiple trapeziums
c) delete void shapes but leave associated reinforcement (individual bars only) in the remaining shapes (allows circular reinforcement patterns to be defined in any shaped column).
7. Add data checks for live load reduction factors to stop the definition of illogical values.
Changes in V6.1.2.7 - 20/01/06
1 Fix problem with warning about illegally dimensioned layers
Changes in V6.1.2.6 - 22/12/05
1 Fix problem with Info dialog .
2 Added context sensitive (?) help to dialogs.
3 Added option to view concrete shape, plan or elevation, on loads graphics.
4 Fixed problem with generation of section shapes where column/middle strip line crosses drop panel sides.
Changes in V6.1.2.6 - 16/12/05
1 Added Column Grid Reference in the columns data screen. RAPT allows the designer to define the grid reference number of any support points to allow the designer to match the grid numbers in RAPT to those on the drawings for the member/panel being designed. This is a text field and the length of the text string is limited to 256 characters. RAPT will only use the first 3 characters in the graphics and text output. The Column Grid Reference will default to the column/support number e.g. 1, 2, 3, 4, 5 for a 4 span frame.
2 Moved Column Shortening from the General Data screen to the Column Data screen with an option to set it individually for each column.
3 Added Special Copy/Paste options to Loads, Reinforcement and Elements to allow the designer to copy and paste multiple complete rows (sets) of data automatically. This avoids the problems encountered with hidden columns and the data verification and data resetting problems that often occur when the data is copied using the standard Windows Copy/Paste functions in the General Toolbar. The new Copy/Paste functions are in the Special toolbar for each window. The General Toolbar options are still available for Windows Copy/Paste functionality.
4 Modified the Cursor shape in the Frame views to show the viewing direction for sections etc.
5 The help screens and manual have been brought up to date for the changes made to the Frame design options over the last 12 months.
6 Fixed problems with conversion of DOS files.
7 Fixed problem with installation for BS8110 design code.
Changes in V6.1.2.5 - 21/11/2005
1 Fixed calculation problem in column Slenderness calculations introduced in version 6.1.2.1
2 When editing a data cell and a red errorcell appears, Esc now undoes the edit and returns the previous value in the data cell.
3 Fixed inconsistency in the graphics for service stresses around the point of contraflexure.
Changes in V6.1.2.4
1 Fixed intermittent problem with continuous graphics regeneration in some background screens giving the appearance of an endless calculation loop.
2 Fixed problems with calculation of surface levels and section properties for some complicated shapes involving voids.
3 Fixed problems with adding horizontal steps and rebates in two way beam systems.
4 Added Zoom to column interaction diagram output.
5 Added option to plot point on curve of interaction diagram based on a user defined Axial Force.
6 Added extra options for the display of design points on interaction diagrams. Labels have been added and the points shown can be grouped according to matching labels.
Changes in V6.1.2.3 - 5/10/2005
1 ACI 318 Capacity Reduction factor for Shear is incorrect in the design code file for ACI. The load combination factors had been changed to agree with the latest version of ACI318 but the capacity reduction factor had not been modified to suit. This does not affect the default files for other design codes based on ACI as these have not been modified to the new ACI318 values.
2 Calculation problems with the combination of elements and layers in the last version which caused endless calculation loops and some incorrect surface levels have been fixed.
3 Added Toolbar option in Frame graphics to draw plan and elevation views at consistent vertical/horizontal scale. The default is still to plot to fit the available space.
Changes in V6.1.2.2
1 The default treatment of Design Service Levels in the general Screen of Frame input has been modified. If will now default to "Extreme Surface" for new runs. This will remain as the default setting for normal slab and beam systems.
If an element is added, RAPT will automatically change the Design Service Level to Program Default in anticipation that an added element might require a different level be selected. The designer can then change it back if desired. After the first element is added, RAPT will accept the setting selected by the user and will not modify it further if more elements are added.
2 In previous versions of RAPT, adding multiple void elements to a concrete face to change the extreme fibre depth caused unrecoverable calculation problems. This has been fixed in this version.
Changes in V6.1.2.1 - 12/8/2005
1 Modified service stress calculations for the uncracked section checks. The transformed section properties are now used instead of the gross section properties. This will reduce the stresses and make the relationship between the cracked and uncracked stresses more consistent as the cracked stresses have always been based on the transformed section.
2 In Steps Input, the dialogs for adding steps have been completely redesigned with a graphical layout to show the options more clearly. The manual has not been updated for this yet.
3 Multiple copies of RAPT can be run on a computer now. On network dongles, each copy of RAPT running will be logged in as a separate login.
4 Bug in pattern loading for runs with left cantilevers has been fixed.
5 Bug in the combination of user defined moment envelopes has been fixed.
6 Problem with rigid steps in the punching shear zone for BS8110 and CP65 runs has been fixed.
7 Incorrect punching perimeter for external panels fixed.
8 Greatly improved the redraw speed for prestress profiles.
9 Improved the Triangular element shape functionality in Column Design.
10 Added Toolbar option in Frame graphics to draw plan and elevation views at consistent vertical/horizontal scale. The default is still to plot to fit the available space.
11 Added an extra column of data in the Prestress Drape Locations View to define the number of continuous strands in each tendon in each span. The number of strands present at each anchorage is also now nominated beside the anchorages on the graphics.
12 Plus many small changes and improvements to prestress tendon reprofiling, tendon profile calculations and other functionality.
13 Cross-section design is nearly completed and will be coming soon.
Changes in V6.1.1.9 - 27/6/2005
1 The methodology used for selecting cells for editing has been changed to more closely resemble the Excel logic. A single left mouse click will select the data cell in Overtype mode. A double left mouse click will select the data cell in Edit mode if the click is within the length of the text in the cell, otherwise it will be in overtype mode. For more information see Section 4.4.2 Cell Editing and Navigation of the manual/help.
2 An option to nominate a starting page number for the creation of the report for each RAPT run has been added. The default is 1, which will work the same as previously. For more information see section 7.3.1.3 Creating A Report of the manual/help.
3 In horizontal steps, the dialog for the rebate option has been completely redesigned with a graphical layout to show the options more clearly. The manual has not been updated for this yet. In the next release all step dialogs will be changed to the same graphical format and the manual will be modified to reflect the changes.
4 Where a second vertical scale is required on the graphics, the right hand scale has previously not been rounded to logical numbers. This is now fixed so the right scale is more easily readable.
5 Several instances where modifying concrete shapes or prestress tendon data have caused illogical reprofiling of tendons have been fixed, especially where sloping straight lengths are used at the ends of a span. Generation of the tendon profile and prestress actions has also been improved in some cases.
6 Fixed problem with full vertical step with negative taper length (taper before step).
7 Fixed problems with updating of graphics in some cases.
8 Improved the reinforcement detailing logic in some cases.
9 Modified output tree functionality so that only the folder and sub-folders containing selected nodes are opened when traversing with Ctrl+PageUp/PageDown.
10 Adding line reinforcement for column design has been improved where the end of the line meets a sloping surface.
11 Slenderness calculations for BS8110 have been fixed.
12 Plus many small changes and improvements to functionality and output formatting.
13 We have noticed that using the Windows XP Style for Display Properties->Appearance->Windows and Buttons results in a background colour for menus which is White. This can be modified by selecting the Display Properties->Appearance->Windows->Advanced Button; under Item: select "Menu" and then select another pale colour which suits the remainder of your colour scheme other than white. This will then allow you to see the selected items in the Tree Menu in both Input and Output which use the menu background colour for shading.
Changes in V6.1.1.8 - 15/2/2005
1 Fix problems with calculations for punching shear for BS8110 where transverse punching shear data defined.
2 Add Copy/Paste Icons to toolbar for prestress tendons control grid.
3 Add delete All icon to toolbar for User Defined reinforcement.
4 Add graphics interaction for selecting tendons in prestress graphics. If the user clicks within 5 pixels vertically of a tendon, RAPT will select that tendons data as the current tendon. If more than one tendon is within the 5 pixel range of the clicked point, RAPT will select the next tendon in the control grid that is within the clicking distance.
5 Add data check for transverse beams to ensure that the transverse beam depth is not equal to the slab depth either side of the transverse beam.
6 Report the actual low point profile point and value for skewed parabola profiles on the prestress tendon input graphics with the mid profile location shown also but without a value.
Changes in V6.1.1.6
1 Fix problems with creation of tendon profiles in last span.
2 Fix problem with extending distributed loads when right end cantilever added and right end length = 0.
3 Fix intermittent problems with sizing of I dialog in output (when prestress screen in input had been viewed).
4 Fix cursor line in reinforcement graphics for 2way systems.
5 Add "length between cursor points" in output graphics. If the designer has selected a cursor location and uses Ctrl + Left Click to select another point, the location of the new point and the distance from the previous point are displayed on the status bar at the left side.
6 In column reinforcement input, once a group of reinforcing bars has been selected and displayed as discussed in V6.1.1.4 - 6 below, a group of the displayed bars can be selected using standard Windows selection methods with the mouse and/or keyboard. Once selected, if all of the selected items are of the same reinforcement type, pressing the right mouse button will display a right click menu which allows the common reinforcement information in the selected items to be modified using a single dialog. All will be modified to the same set of data. The reinforcement type of the selected group cannot be changed.
Changes in V6.1.1.5
1 Fixed problem with automatic adjustment of prestress locations with change in right cantilever length.
2 Added error check to not allow the length of a cantilever to be less than the length of a transverse beam or drop panel in the cantilever. A red error cell will block the data change. The drop panel or transverse beam dimensions must be modified first.
3 Fixed a problem with modifying prestress tendon sizes when the tendon type is changed and the number of tendon sizes available for the new tendon type is less than the number of the current tendon size.
4 Improved the column design output information, especially for Range of Bar Size checks.
Changes in V6.1.1.4
1 Grossly overloaded members with extreme ductility problems now produce results in RAPT V6 so that the designer can see where the problems lie. A problem with this routine has been fixed in the latest version for severe cases of overloading.
2 RAPT allows the designer to nominate the location of the critical design section near the face of the support in the input as a fraction of the half support length. Unrealistic values input here were causing design errors. This has been trapped both in the input data checking and at the design stage.
3 A problem with the creep losses calculation for members with large steps has been fixed.
4 Tendon profile errors that occur in the output calculations now produce error messages that relate back to the input data. Previously they were treated like any other output error and were not related to the input data.
5 Column design for codes other than AS3600 had a problem with the selection of the code to design for. This has been fixed.
6 Column design reinforcement interface has been improved to allow the designer to more easily distinguish between different sets of reinforcement. If multiple bar types are selected using the mouse or toolbar icon or if two bars on top of each other are selected by selecting one bar with the mouse, a table listing the bar types selected is opened on the top right of the screen and these bars will be shown as a dark blue colour on the graphics.
The designer can select to view the bars for each type selected using a single mouse click in this table of the up/down arrow keys. The selected bar types in the table will show as a cyan (light blue) color compared to the dark blue of the other types in the table. The selected bar types can be deleted from the shape using the delete key in this table. Double clicking on one bar type in the table will open the modify reinforcement dialog for this bar type.
--NOTE-- The reinforcement dialog has a name at the top. When adding a new reinforcement it will be "Add Reinforcement.........". When modifying an existing reinforcement type it will be "Modify Reinforcement........."
Changes in V6.1.1.3 - 10/12/2004
1 Released for CD copying.
2 Default reinforcement sizes modified for middle strip of two way beam systems to select slab type reinforcement. Warning added for these cases regarding left over moment in column strip.
3 Fixed some interface problems in column program.
Changes in V6.1.1.2
1 Add copy capability from output text results. User can select individual or groups of tables of data and copy them to the clipboard and paste to other programs such as Excel, Word, Notepad in same format.
2 Fix problem with zero depth elements.
3 Fix problem with negative area of reinforcement in highly compressed PT members.
4 Fix several problems with Column program, mainly in slenderness reporting.
Changes in V6.1.1.1
1 Added data field in General Data for frame input to allow the designer to control the way RAPT calculates the Top and Bottom Reference surfaces for reinforcement design zones and prestress tendon cover.
2 Added more functionality to column design program and finished output report options for output of defined data for column design.
3 Improved warnings for reinforcement zones and user defined reinforcement.
Changes in V6.1.1.0
1 New version of column design allowing reinforcement patterns to be inserted as individual bars. Individual bars can be drag/dropped to new positions. Text output added. Improvements in other areas.
2 Improved data checking for prestressing. Checks on tendon cover now only carried out after tendon profile calculation succeeds. Fixed problems with profile generation for some complex profile shapes.
3 Fixed problems with designed mesh inserted back into input.
Changes in V6.1.0.9 - 20/11/2004
1 Added new rules for low ductility reinforcement for AS3600 Amendment 2. Modified rules for crack control for this amendment were added in earlier releases.
2 Added Column Design as a Beta release.
3 Fixed some problems with checking for steel cover.
4 Fixed intermittent problems where a run would crash after modifications to prestress and then when the same modified file is reloaded, runs perfectly.
Changes in V6.1.0.7
1. Fixed problems with warning/error message in reinforcement input.
Changes in V6.1.0.6 - 21/10/2004
1. Fixed problems with prestress input screen.
2. Fixed printing problem that occurred on some users.
Changes in V6.1.0.5
1. Added data checks for reinforcing zones - produces an Input Error if the zone is outside the concrete surfaces or an Input Warning if the zone is less than 20mm inside the closest concrete surface. These checks are done at each end of each zone and at all change in section locations. Double clicking on the warning message will take data focus to the zone that is causing the problem.
2. Added data checks for reinforcing bars - produces an Input Warning if the bar is less than 20mm inside the closest concrete surface. These checks are done at each end of each bar and at all change in section locations. If a reinforcing bar is outside the concrete surface it will be ignored for all calculations. Double clicking on the warning message will take data focus to the bar that is causing the problem.
3. Added data checks for prestress tendon profiles - produces an Input Warning if the tendon duct surface is less than the nominated default surface cover inside either concrete surface. These checks are done at all transition points and peak points in each tendon profile and at all change in section locations. If a tendon is outside the concrete surface it will be treated as unbonded at those points. Double clicking on the warning message will take data focus to the span of the tendon that is causing the problem.
4. Fixed problems with steps which are a combination of a step and a taper on the same surface.
5. Fixed problems with Undo.
6. Fixed problems with deflection and transfer load combinations allowing moment envelopes to be included in the combinations.
7. Fixed problem with flexural reinforcement warning when tension reinforcement has to be added to solve a compression problem because the reinforcement centroid is too close to the compression face.
8. Fixed problem with automatic resetting of tendon end locations when end span length adjusted.
9. Manual in PDF format available for download from website.
Changes in V6.1.0.4
1 Fix for automatic update of tendon data for change in span lengths
2 General fixes for minor interface problems
Changes in V6.1.0.3
1. Modified prestress forces calculation for creep losses. The creep losses is now calculated based on the compressive stress in the concrete at the level of the tendon under the transfer prestress condition with the permanent loading applied. This will often lead to increased prestress forces but may in some extreme cases lead to reduced prestress forces.
2. Fixed and modified the line thickness option in output to printers
3. Fixed problems with UnDo for added load cases.
4. Fixed some minor problems with concrete shape graphics.
5. Fixed problem with default jacking force for pretensioned members.
6. Fixed some output formatting problems.
Changes in V6.1.0.2 - 2/8/2004
1. Reinforced Member Crack Control: Ast.min calculation has been removed from RAPT. The AS3600 committee has voted to remove it from the code and an amendment 2 to AS3600 will be released shortly to this effect. If, for some reason, a designer needs to allow for this reinforcement in a design, this will have to be done manually by the designer.
2. Allow the definition of separate font sizes for output to screen and printer.
3. Fixed printing formatting problems.
4. Fixed Windows Exception Errors for Undo in some extreme cases.
5. Updated help screens.