Restraint Effects in Reinforced and Prestressed Concrete Structures

Restraint effects on cross sectional and structural level were analysed for reinforced and prestressed concrete structures. Material nonlinearity including crack initiation and tension-stiffening approaches were implemented in the numerical solution. In the range of service load state the results show that a linear solution for restraint effects leads to higher section forces and required in consequence more reinforcement. A nonlinear material modelling, which allows crack formation and therefore redistribution of the section forces identified a distinctive reduction of the restraint forces in contrast. As a consequence, a linear solution method should not be used for the analysis of structures which are subject to significant restraint effects. Integral or semi-integral bridges are mentioned here as an example. These considerations are in fact imperative for designing cost- effective structures.