Optimal Selection of Loading Age for Concrete Slab of Composite Beam Bridge in Ningxia Area

Zhenye Yu 

School of Civil Engineering, Chongqing Jiaotong University, Chongqing, 400074, China 

Abstract: In order to study the effect of shrinkage and creep of concrete deck on the structure of bridges in Ningxia area, the finite element model of Curved Steel-Concrete Composite continuous beams is established by using Midas/civil. The deformation, internal force and stress caused by shrinkage and creep effect under different loading ages were analyzed, and the optimum loading age was discussed. The results show that with the increase of loading age, the shrinkage and creep deflection, bending moment and beam stress decrease gradually, and the decreasing trend becomes gentle with the increase of age, and the influence of shrinkage and creep on deflection, bending moment and beam stress is not obvious from 100 days of age; the influence of loading age of concrete bridge deck on the bending moment of steel beam is small. For steel-concrete com-posite girder bridges in Ningxia, under the condition of limited construction period, the maintenance time of concrete deck can be reduced to about 3 months. 

Keywords: Ningxia area; Composite beam; Shrinkage and creep; Loading age