EXCESSIVE MULTI-DECADE DEFLECTIONS OF PRESTRESSED CON- CRETE BRIDGES: HOW TO AVOID THEM AND HOW TO EXPLOIT THEIR MONITORING TO IMPROVE CREEP PREDICTION MODEL Abstract Stimulated by the excessive deflections and collapse of the KB Bridge of world-rercord

Stimulated by the excessive deflections and collapse of the KB Bridge of world-rercord span, the deflection histories of 56 similar bridges, most of them excessive, have been collected by RILEM TC-MDC. They amount to a wake-up call: The standard creep recommendations of engineering societies have been misleading, and thus their revision is imperative. They also confirm a simple feature: The multi-decade trend of bridge deflection, and by implication also the concrete creep law, is a logarithmic curve in time, which has no final bound, in contrast to the existing standard recommendations. Despite the lack of success in obtaining full information on the highly deflected bridges, it is possible to benefit by statistical analysis from the bridge deflection data for improvements of the concrete creep model. The proceedings paper briefly outlines how to do that, and the full paper presents some more detail and the figures. fib Symposium PRAGUE 2011 Session 3-4: Modelling and Design