Prestressed Beton Girder in state II
Recalculation of a large-scale test by BASt
In this example, a large-scale test was recalculated, which was carried out as part of a research project of the BASt at the TU Dortmund University on a two-span beam DLT1 prestressed in a post-tensioned composite (Maurer, et al., 2015).
The calculation model was chosen as concrete surface area structure (C35/45 according to DIN 1045-1) with steel bars for longitudinal and stirrup reinforcement (mesh width 5 cm). The concrete behavior in the tensile zone was assumed to be softened with a residual tensile strength of 0.1 fctm.
The program automatically incorporates the tendon into the element stiffness matrices of the surface elements as part of the load case calculation.
Up to a pressing force of approximately 700 kN, the test behaves more compliantly than the comparative calculations. Above 700 kN, due to crack formation, the load-displacement curves increase approximately parallel to the test results. The results show good agreement with the test. Deviations can be explained, among other things, by the use of standard values for the concrete. In particular, the Young's modulus of the concrete and the prestress froce at the time.
