Tensile behaviors of reinforced-UHPC members subject to uniaxial loading: experiment and numerical simulation

The exceptional tensile properties have become the primary concern in the application of ultrahigh- performance concrete (UHPC). To investigate the tensile and cracking behaviors of steel reinforced UHPC (R-UHPC), eight R-UHPC members with various steel reinforcing ratios and fiber volumes were tested under uniaxial tension. The tests revealed that higher fiber volume, or larger rebar diameter, would lead to closely-spaced cracking and fine cracks. Additionally, higher reinforcing ratio would increase the cracking load and ultimate tensile capacity, and enhance the stiffness of R-UHPC after cracking, thus improving its plastic capacity. Based on the tests, a novel numerical model was proposed, which integrated a concrete damage plasticity model for UHPC materials and cohesive element for UHPC-rebar interface. Subsequently, a comparison was made among the numerical simulations and tests, demonstrating good performance of the proposed numerical model.