Bond between prestressed steel and concrete—computer analysis using ADINA

Abstract

A comprehensive test series was carried out to study the load carrying behaviour of pretensioned hollow-core slabs, which are not in accordance with the German building codes because of their geometry and the lack of conventional reinforcement. It was found that a number of problems concerning the end anchorage zones of the slab cannot be simply solved by experimental means with reasonable expense. Therefore a finite element analysis using the ADINA program was carried out. The intent of this contribution is to show that the modular structure of the ADINA program is extremely suitable for modification by the user for the analysis of structures whose load carrying behaviour cannot be reproduced adequately by the original version of the program. A contact element with a nonlinear bond-slip-relation is presented and added to the program, maintaining completely its modular structure. Special attention is paid to the derivation of the bond stiffness, which is of special influence on the numerical results. The validity of the computer analysis is judged by comparing test measurements of bending tests and analytical results. Although this study is restricted to a 2D representation of the real three-dimensional reinforced concrete structure with a varying cross-section (and is intended to be a preliminary study), the results are excellent and can be used to draw conclusions for the design problem.