B8 | Prestressed Concrete Girder | Update Information
- Fixed error in stress determination for prestressing steel (in rare cases extrem value when transition uncracked to cracked)
- Fixed error in stress determination for concrete in state II (in rare cases no result, caused by incorrect effective creep modulus)
- NA Austria: vertical and horizontal minimum distances Reinforcing steel with correct K1 and K2
NA Germany, Proof of Joint Load Capacity B>: DAfStb book Number 630 requires that the shear forces due to time-dependent stress redistribution have to be taken into account for prestressed components. In the program, the proposed approximation was realized. At the ends of the beam up to a depth of 50 cm the joint reinforcement is increased with a surcharge of 2 cm2 / m.
- The current Austrian national annex ÖNorm B 1992-1-1: 2018 was implemented
- Loads can now also be assigned to alternative groups.
Input prestressing steel:
The pre-set prestressing steel "SpSt1570 / 1770" is now correctly marked.
Input Table for pre stressing steel layers:
When deleting a layer information according isolation could be lost.
The number of prestressing steels shown in the case of continuous and isolated tensioning steels of the same distance was not reproduced correctly.
In the case of a single load directly above the support, their share was absent from the listed support loads in the output document.
Verification for anchorage of tendons (prestressed steel):
- a "user defined" transmission length was not taken into account correctly
- For symmetrical girders, the areas at the beginning- and end of the girder were not equal
- For girders with Pi cross-section, the absorbable force in the prestressing steel was set too low
- A reduced partial safety factor of the concrete was not considered
Fixed an issue where after errors in the calculation in the input tables points instead of commas occurred and values were rounded impermissibly.
user-defined entry of the shrinkage dimension:
The input for Eurocode was only possible with negative signs, which led to incorrect results. That was corrected.
Fixed bug in the output tree.
Load combinator DIN4227T1:
In determining the permanent loads, the variable loads were not mitigated with the constant coefficient
Output for DIN4227T1:
No creep and shrinkage were reported.
Output for a section:
- Table bending capacity: columns MEd and MRd were reversed
Verification of lateral buckling for the errection state:
- Height of the attechment points added
Correction calculation part:
NA Germany, increased minimum cover for bond for prestressing steel:
- according to DAfStb H. 600 in the general case increased by 0.5 * dp
- for strands to 3.0 * dp (previously 2.5 * dp), otherwise 3.5 * dp (previously 3.0 * dp)
the previous lower values apply
- at clear distances of the prestressing steels of s> = 2.5 * dp or
- at a lower stress of prestressing steel in the stress bed Sigp (0) <= 1000 N / mm2
NA Germany, Guidelines:
- If the minimum concrete cover for bond is decisive, the allowence will not be reduced below 1.0 cm even with special quality control (DAfStb H.600 p.151)
NA Germany, relaxation index Litz with very low relaxation:
- Value changed to 2.0 for Ri / Rm = 0.8 and t = 10h (previously 2.1)
NA Germany, Durability Dialog:
- new option for clear spacing of the prestressing steels s> = 2.5 * dp
NA Germany, default value for prestressing steel stress in the stress bed:
- The default value has been reduced to 1000 N / mm2 in order to avoid an increased concrete cover for bond in accordance with DAfStb H.600 p.150 compared to NA.
The advicer has been revised and improved in some points.
Recommendations were added in case of non-compliance with the verification of lateral buckling.
- Completely new program output German / English / Polish
- Documentation in English and Polish completely revised
- Fixed bug with user-defined actions in dialog Basic data
- Fixed bug when saving the internal forces inputs for the "single cross-section" type
- Fixed bug according the assignment of prestressing steel "parallel UE" or "parallel LE" after reading
Correction calculation part
- The default value for the number of sections in the Basic grid was increased to 20, in order to improve the accuracy of results in deformation calculations
- The cause of the crash with more than 150 sections in the overall grid was eliminated
- An error in the assignment of the user defined sections was fixed, possibly. results were not found
The utilization for crack width design in the case of reinforced concrete was related to the permissible crack widths for prestressed concrete.
Creep modulus calculation for time sections with elevated temperature is corrected.
In case of holes the automatically generated sections are corrected according to the type of the hole.
In the case of the minimum reinforcement for the crack width limitation on the bottom side, a higher mean reinforcement distance is obtained by taking into account the prestressing steel layers, resulting in a higher hcef and ao. a slightly higher req. As . At the same time, the chargeable prestressed reinforcement is also higher in some cases, so that the effects on the utilization (req.As/exist.As) are relatively low.
It is possible again to enter a user-defined area without shear design.
The default value for the number of sections in the basic grid is increased from 10 to 20 sections.
The table shear reinforcement is corrected for the case of in-situ concrete reinforcement (columns "Joint asw" and "Eta vRdi").
Input cross section for in-situ concrete:
- Selection box for joint formation has beencompleted.
- The surface depth of the finished part formwork could not be edited in former version
user defined input compressive strength medium value :
- is now correctly considered in the computing part
- t0= 1d for creep period Storage also in the case of in-situ concrete accepted
Calculation - load combinatian in case of dependend vaiable actions:
- The decesive action has only been updated in case of an unfavorable change
Calculation - creep coefficient for in-situ concrete reinforcement:
- is now determined with t0E (creep start for in situ concrete) instead of t0 (release anchor).
Calculation - Minimum Reinfocement for bending :
- The minimum reinforcement was too great for the cantilever arms and the tension zone on top side
Calculation - NA Austria and stress verification prestressing steel:
- Determination of the ksi1 value for the prestressing steel tension has been corrected.
Output - Graphic for concrete compression stresses changed:
- instead for the permanent combination (only informative), the stress curve for t = t0, the release of the anchoring of the prestressing steel (necessary verification) is shown
Output - table for shear capacity verification along the girder:
- Sections x < section for design: for the strut angle and shear reinforcement of the values from the section for design are adopted.
Output -table of the prestressing steel layers:
- Number of isolated bars is now correct.
Output - table for verification of anchorage of the prestressing steel:
- the outfit was improved by adjusted column widths.
Change to a more recent version of the same country:
- user defined values of the item will not be replaced by standard values
Current versions for the National Annexes NA to BS EN 1992-1-1, PN EN 1992-1-1/NA, DIN EN 1992-1-1/NA and ÖNORM B 1992-1-1 implemented.
Depending on the National Annex consequence classes can be taken into account.
Deflection check according to EN 1990 A1.4.3 (1) for each combination of SLS possible.
- Optional user-defined actions possible.
- Optional user-defined concrete compressive strength at the time of prestressing force transfer.
- Consideration of a heat treatment, a gradual prestressing force transfer and increased allowable compressive stresses during re-prestressing possible.
- Detailed output for anchor design and deflection check.
- Extended output for accidental situation and earthquakes (graphics, design in table and at the section).
- Stress limit for nonlinear creep for "failed checks" and "critical sections" only as information.
- Deflection calculation: Adjustments in determining the curvature of shrinkage and the curvature of bending and for the used creep values.
- The use of the effective creep number has little influence on concrete and steel stresses in the state of long term effects.
Optional the rebar diameter can be set differently from the customary diameter list by the user.
Girder with in situ concrete: The design and report of sectoins for the horizontal shear connections are changed to the critical sections. The horizontal shear connection is a specific design criteria now including full documentation (overview, table, shear design graphics/output).
Load combination decompression: XD1 is calcualted with quasi-permanent instead of frequent combination now.
Problem with loading of old items and DIN 4227 as standard is solved.
Problem with Eastern European typesetting fixed and localization completed.
DIN EN 1992-1-1/NA implemented, replaces previous existing optional DIN ENV 1992-1-1 (EC2)
display problem of the triangular load fixed
English translation of the output improved
Determination of the minimum reinforcement for limitation of crack width:
In the case of the tendon type "wire" the prestressing steel area was not considered.
resisting tensile force:
The results for a three-membered strand were too much on the safe side.
Output in proportional pitch improved.
Decompression check was not performed
Criterion for non- linear creep:
So far, general sigc <0.45 * fck
Now for t = Solve anchoring sigc> 0.45 * fck (t)
Regard to stress exceeded:
For t = Solve anchoring when sigc> 0.6 * fck (t)
Actions in the dialog for reinforcement:
caused an incorrect representation of the result graphs. Cause has been turned off.
Crack width limitation
sometimes. was no evidence led connected with the incorrect message "no reinforcement in the tension zone. Cause has been turned off.
transverse tensile reinforcement:
Laying length was sometimes erroneous, corrected.
Crack width limitation:
In case of the cross section has only tension strains, sometimes the strain state determined incorrectly, which resulted in too large crack width.
For new positions, the standard of the last saved position is the default.