Time-dependent calculation method for the long-term deformation of recycled aggregate concrete beams
Bai Guoliang1 Qin Chaogang1 Zhang Yu2 Liu Chao1,3 Han Yuyan1
1. School of Civil Engineering, Xi′an University of Architecture and Technology, Xi′an 710055, China
2. Design Institute of Xi′an University of Architecture and Technology, Xi′an 710055, China
3. School of Science, Xi′an University of Architecture and Technology, Xi′an 710055, China
Abstract：Under the long duration load, the recycled aggregate concrete beams may suffer substantial additional deformation due to the shrinkage and creep effect of recycled aggregate concrete. Based on the long duration load experiments of recycled aggregate concrete beams with different replacement ratios of recycled aggregate, the time-dependent calculation method for the long duration deformation was studied. According to the virtual work principle, the computational formula for long-term deformation, in which the effective elastic modulus method with age of concrete considered was employed and the creep factor of recycled concrete was introduced into the calculation of additional curvature of beam section, was given. Based on the calculation formula of creep and shrinkage for ordinary concrete, the creep and shrinkage adjustment coefficients of recycled concrete with the effect of adhering cement mortar considered were provided. By substituting the calculation results into three typical creep and shrinkage models of ordinary concrete, the creep and shrinkage model for recycled concrete was derived. It was found that based on the proposed formula, the calculated mid-span deformation, the additional deformations at mid-span and loading point agreed well with the experimental results.
