Dynamic tensile test of mass concrete with Shapai Dam cores

Static and dynamic tensile tests of dam concrete cores were carried out to investigate the dynamic properties as well as the tensile stress-strain relationship under either monotonic or cyclic load. The test specimens were prepared from the cylindrical cores drilled from Shapai Arch Dam, which was built with three-graded roller compacted concrete and survived the strong shaking of Wenchuan Earthquake. Direct tensile tests were performed on an MTS servo controlled testing machine and the system displacement was used as the control command for all tests. The test results indicate a significant increase in strength compared with static ones, from 2 to 47 % under strain rate roughly from 10(-4) to 10(-2)/s, and more fracture energy is consumed by the concrete under dynamic or cyclic loading than static monotonic loading. Furthermore the static preload on the specimens shows little influence on their dynamic tensile strengths. Based on the experimental data, a simple analytical model was proposed for entire stress-strain relationship under both monotonic and cyclic tensile loading, the calculated stress-strain path gives a satisfactory approximation which can be used in dynamic numerical analysis of concrete dams.