Estudio del comportamiento en servicio de puentes pretensados de hormigón y estructura mixta

Behaviour of concrete and composite prestressed bridges under serviceability limit states

Different types of both concrete and composite girder prestressed bridges under service loads are analized. The analysis is performed by a ste-by-step computer simulation which very accurately takes into account th complex process of stress redistributions between concrete and steel elements. We can conclude that the stress level at the most tensioned concrete fibre is not an adequate parameter for the prestressing dimensioning. This is due to its great sensitivity to the precision level of the analysis, the sequence and timing of the erection process, the time-dependent and mechanical properties of the concrete and other variables of difficult evaluation. An accurate control of crack opening as well as the post-cracking behaviour of the cross sections is the only guarantyy to ensure good durability of prestressed structures.