The reversed cyclic load tests of normal and pre-stressed concrete beams

Seven high-performance concrete (HPC) beams and two counterpart normal-strength concrete (NC) beams are tested under reversed cyclic vertical displacement to investigate the seismic behaviors of normal and pre-stressed HPC beams. The failure patterns, skeleton curves, hysteretic model, displacement restoring capacity, ductility, stiffness degradation and energy dissipation capacity of HPC beams are discussed. An M – ϕ hysteretic model for HPC beam sections is proposed in this paper. Studies indicate that the normal beams behave in a more ductile manner in comparison with the pre-stressed beams. Relatively high deformation restoring capacity could also be observed clearly in the pre-stressed HPC beams. Tests also show that the energy dissipation and deformation restoring capacity of HPC beams can be improved significantly in the last period of loading by using blast-furnace slags and polypropylene fibers. Beams with silica fumes have behavior that is not as ductile compared with that without silica fumes. In addition, higher reinforcement also leads to a decrease in the displacement ductility of HPC beams.