Experimental study on flexural behavior of new type of prestressed reactive powder concrete sound barrier for high-speed rail

摘要

In this paper, four-point bending tests of six prestressed reactive powder concrete (RPC) sound barrier unit panels were performed, the flexural behavior, deflection, and failure modes of both in situ and prefabricated panels were studied. The results show that the major failure modes for in situ panels were bending failure. Prestressing the panels can effectively increase the cracking loads and improve the stiffness of the in situ panels, but it cannot improve the ultimate flexural capacities. The ductility of the in situ panels decreased with the increase of prestressing degree. The stiffness of the prefabricated panels was improved by prestressing. Increasing the thickness of back and front plates, the ductility of the panels decreased accordingly, and the ductility of the prefabricated panels decreased more obviously than that of in situ panels. Based on the test results, considering tensile strength of RPC and prestressing stress, a modified formula for flexural capacity of in situ panels was established. In the meantime, considering the "bridge" effect of steel fiber, the formulae to calculate the crack width and deflection at service limit state were also developed for future design.