Behaviors of semi-precast beam made of recycled aggregate concrete

SUMMARY This paper presents behaviors of semi‐precast beams made of recycled aggregate concrete (RAC) including flexural and shear performance. Specially, cracking patterns, deflections and bearing capacities of U‐typed and C‐typed beams are intensively examined, analyzed and discussed. In the study of flexural behavior, a main parameter is reinforcement ratio, whereas the shear span‐to‐depth ratio and types of precast section are parameters in the investigation of shear behavior. First, the flexural tests show that the bearing capacity and stiffness of RAC beams are increased with the increase of reinforcement ratio, whereas the ductility is decreased with the reinforcement ratio; the plane section assumption that applies to semi‐precast beam with RAC is possible. Second, the shear tests show that the shear capacity of RAC semi‐precast beam increases with the decrease of the shear span‐to‐depth ratio. The types of semi‐precast section have no significant influence on performances of semi‐precast beam. However, the testing phenomenon of the interface between the precast and cast‐in situ parts is presented in this study and needs further study. Finally, both flexural and shear test results reveal that the formulas in the current Chinese technical code for RAC are feasible for design. Copyright © 2013 John Wiley & Sons, Ltd.