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Check of prestressing reinforcement is available in version 2011 if the prestressing tendon is defined in a rib of the slab (on the 1D member). This is the third type of modelling. Then Check of prestressing from the branch Concrete Advanced > 1D members > Check of prestressed concrete > Check of prestressing reinforcement can be used.
Check of prestressing reinforcement
When we use the model with the real tendon in the slab directly then the service for 1D element cannot be used. There is possibility to display results in the Results > Beams > Tendon stresses.
These values are code independent. It means without proper calculation with coefficients (e.g. rsup, rinf etc)
The structure is 2D. It means time dependent looses are not covered in the calculation. That is why we receive zero losses (LCS) and higher maximal stresses (MaxStress)
Tendon stresses
The following checks should be performed according to "EN 1992-1-1 Eurocode 2, Design of Concrete Structures – Part 1: General rules and rules for buildings, European Committee for Standardization, December 2004.". These are the required checks:
SCIA Engineer provides only values named as “after anchoring” in the service Tendon streses. Stress in the prestressing tendon prior to and after anchoring is evaluated for combination ULS_short. The detailed results are shown in the following table. The maximal value of concrete stress after anchoring is according to 5.10.2.1.
→ OK
→ NOT OK
The results of the stress after anchoring are bit higher in the table below so probably the decrease of the initial stresses for prestressing tendons should be adapted to lower value than original 1450 MPa.
Stress in the prestressing tendon due to cracks or deformation is evaluated for combination SLS_Char_long. The detailed results are shown in the following table. The maximal value of concrete stress from characteristic combination is according to 7.2(5).
The maximal value is higher than allowed but due to the fact that the losses from creep and shrinkage are not covered in this calculation the maximal value will be probably lower than the allowed stress of 1395 MPa.
Detailed calculation of the losses for each tendon is possible when you use action button Tendon losses when you select some tendon from the property window.
Action button tendon losses
Tendon losses
This check is not possible for 2D members in SCIA Engineer 2011 at all. User can evaluate only concrete stresses in menu Results > 2D members > Member 2D stresses.
Member 2D - Stresses
For each combination the results are displayed and user can check the values with limited values from the code "EN 1992-1-1 Eurocode 2, Design of Concrete Structures – Part 1: General rules and rules for buildings, European Committee for Standardization, December 2004.". The check is performed in three steps. These are the required checks:
Values from the next chapters are evaluated for the model with column heads with real defined tendon.
The calculation of the stresses do not cover the user defined or designed reinforcement. The obtained results can be higher than those calculated with reinforcement.
Concrete stress after anchoring is evaluated for combination ULS_short (After anchoring). The detailed results are shown in the following table. The maximal value of concrete stress after anchoring is according to 5.10.2.2(5).
The time dependent analysis is available only for 1D (plane XZ) element but not for 2D member. It means the current strength of concrete after anchoring has to be calculated manually. We supposed the anchoring of the post-tensioned tendons in 3 days.
The maximal value of concrete strength after anchoring is then
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Concrete stress in the characteristic combination is evaluated for combination SLS_Char_long. The detailed results are shown in the following table. For this combination we check the stress in
Strength of concrete in the working life of 50 years has to be calculated manually. We supposed the working life of 50 years (18250 days).
The maximal values of concrete strength are the following
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You can see that all compressive stress in concrete is lower than the limit value 
When you look at the tensile concrete stress there are higher values (max 5.8 MPa) These stresses will be probably transferred by the reinforcement because the calculation of the stresses does not cover the user defined or designed reinforcement.
Concrete stress in quasi permanent combination is evaluated for combination SLS_QP_long. The detailed results are shown in the following table. The maximal value of concrete compressive stress is according to 7.2(3).
The maximal values of concrete strength are the following
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You can see that all compressive stress in concrete is lower than the limit value 
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There is no special service for Capacity check. The capacity of the slab in ULS can be verified by calculation of the Additional reinforcement in service Design ULS. If Additional reinforcement is equal to zero then the capacity of the slab is OK and no additional reinforcement is required.
Check of cracks in 2D members is not available in SCIA Engineer 2011 but only design of required area of non-prestressed reinforcement is done with respect to the effects of prestressing. This procedure should meet the requirements of the code defined limited cracks widths.
Design of the non-prestressed reinforcement for serviceability limit state is done together with the design for the ultimate limit state in one service Concrete Advanced > 2D members >Design ULS+SLS.
New service of Member check for 2D has been implemented in version SCIA Engineer 2011 and will not be commented more in this tutorial
New service crack width
