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Code[CEB-FIP 1990]: At present, only the CEB-FIP 1990 code is supported. If any other code is required, please contact the support team, and it can be added to the OpenBrIM Library.
Temperature [F]: Temperature during curing
Humidity [%]: Relative humidity during curing
Time Dependent Elastic Modulus[Include/Ignore]: The time-dependent modulus of elasticity is a parameter used to account for the change in elastic modulus over time due to creep and shrinkage for concrete. When the time-dependent modulus of elasticity is included, the modulus of elasticity values entered under basic tab are overridden based on the computed values. According to CEB-FIP 1990, the following parameters are used to compute the time-dependent modulus of elasticity:
Concrete compressive strength at 28 days (fcm)
Cement hardening type
Relative humidity and temperature during curing
Age of concrete at time of loading (t)
These parameters are used to calculate the elastic modulus at different times during the life of the concrete member. In OpenBrIM, all calculations are based on the secant modulus of elasticity. However, CEB-FIP computes the tangent modulus. Once the tangent modulus is obtained using the CEB-FIP procedure, OpenBrIM divides the E value by 1.05 before utilizing it in finite element analysis (FEA). To ensure that this effect is included in the analysis, both the material and stage settings should be selected to include it.
Concrete Creep Effect[Include/Ignore]: Concrete creep is a time-dependent deformation of concrete under sustained load. The CEB-FIP model considers several parameters to determine the creep coefficient, which is used to calculate the time-dependent deformation of the concrete. These parameters include the concrete compressive strength at 28 days (fcm), maximum aggregate size (Dmax), cement type and percentage of cement content, relative humidity and temperature during curing, age of concrete at time of loading (t), and applied stress level (σ). OpenBrIM monitors stress changes at each stage and calculates creep accordingly by utilizing these parameters. To ensure that this effect is included in the analysis, both the material and stage settings should be selected to include it.
Concrete Shrinkage Effect[Include/Ignore]: Concrete shrinkage refers to the reduction in the volume or size of concrete over time due to the loss of moisture. When concrete is first poured, it contains a lot of water which evaporates gradually over time causing the concrete to shrink. This can result in cracks or deformations in the concrete which can affect its structural integrity. The parameters used in CEB-FIP for concrete shrinkage are the age at loading, the age at unloading, the duration of loading, the humidity of the environment, and the type and composition of the concrete mix. Additionally, CEB-FIP also considers the influence of creep on shrinkage. To ensure that this effect is included in the analysis, both the material and stage settings should be selected to include it.
Steel Relaxation Effect[Include/Ignore]: To account for relaxation effects in tendons, time-dependent material property definitions are assigned to the relevant materials. To ensure that this effect is included in the analysis, both the material and stage settings should be selected to include it.
PT Losses from Structure[Include/Ignore]: Elastic shortening losses refer to the reduction in the length of a prestressed concrete member caused by the initial stress generated during the pre-tensioning process or other external loads that could alter the length of the member. To account for this effect in the analysis, it is essential to select both the material and stage settings that include it.
AASHTO N-3N
Material: Choose the deck material to override for short-term and long-term properties
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