Research On Shear Behavior Of Reinforced Concrete Beams With Recycled Coarse Aggregate

In recent years, some research on recycled aggregate concrete has been carried on in many countries. Some of recycled aggregate concrete has been applied to the actual projects, which is important to save resource and protect environment.Nowadays, the research on recycled aggregate concrete is emphasized on material performance, but the research on structure element performance is not further. Based on the experiment of 12 reinforced recycled aggregate concrete beams with stirrups and natural aggregate concrete beams with stirrups, the failure modes, the diagonal cracking load and shear bearing capacity of recycled concrete beams are investigated. The effects of stirrup reinforcement ratio, shear span-to-depth ratio and concrete strength on shear behavior of reinforced recycled concrete beams are studied, too. The main conclusions are as following:1. The modes of recycled concrete beams in the experiment are shear compressive failure, and the stirrup reinforcement ratio, shear span-to-depth ratio and concrete strength have an effect on the shear behavior of recycled concrete beams.2. Under the same loadings, the mid-span deflection the width of diagonal crack and the stirrup strain of recycled aggregate concrete beams are larger than that of natural aggregate concrete beams.3. Under the same loadings, the stirrup strain and the mid-span deflection of recycled aggregate concrete beams decrease with the increasing of stirrup reinforcement ratio and concrete strength. The stirrup strain and the mid-span deflection of recycled aggregate concrete beams increase with the increasing of shear span-to-depth ratio.4. The diagonal cracking load of recycled aggregate concrete beams is lower than that of natural aggregate concrete beams. Under the same loadings, the width of diagonal crack of recycled aggregate concrete beams decreases with the increasing of stirrup reinforcement ratio and concrete strength, and increases with shear span-to-depth ratio.5. Under the same loadings, the shear capacity of recycled concrete beams is lower than natural concrete beams. The shear capacity increased with stirrup reinforcement ratio and concrete strength. The shear capacity decreases with shear span-to-depth ratio reducing.6. According to the experimental results, the expressions of the diagonal cracking load and the shear bearing capacity of recycled concrete beams with stirrups are proposed.