Effect of concrete creep on pre-camber of continuous rigid-frame bridge

Abstract

The effect of concrete creep on the pre-camber of a long-span pre-stressed concrete continuous rigid-frame bridge constructed by cantilever casting method was investigated. The difference of creep coefficients calculated with two Chinese codes was discussed. Based on the calculations, the pre-camber of a pre-stressed concrete continuous rigid-frame box bridge was computed for construction control purpose. The results show that the short-term creep coefficient and long-term creep coefficient calculated with the CC-1985 are larger than those calculated with the CC-2004, while the medium-term creep coefficient calculated with the CC-1985 is smaller than that calculated with the CC-2004. The difference of creep deformation calculated with these two codes is small, and the influences of concrete creep on the pre-camber for most of the segments are negligible. The deflections and stresses of the box girder measured during the construction stages agree very well with the predictions.

Keywords

creep / pre-stressed concrete / continuous rigid-frame bridge / cantilever casting method / pre-camber