预应力超高性能混凝土梁的受弯性能研究

Research on Flexural Behaviors of Prestressed Ultra High Performance Concrete Beams

对超高性能混凝土（UHPC）的单轴受压应力-应变全曲线和UHPC梁的受弯性能进行了试验研究以及理论分析。研究结果表明：UHPC具有良好的受压变形性能，就试验中使用的UHPC而言，其峰值点应变可达3500×10^-6极限应变可达4500×10^-6；UHPC梁具有良好的延性和极限变形能力，其极限变形可达到梁跨径的1／42～1／34；用提出的计算方法得到的预应力UHPC梁的破坏模式、开裂弯矩、极限弯矩以及钢绞线极限应力与试验结果吻合较好，说明这种计算方法具有较高的精度。

The experimental research and theoretical analysis about uniaxial compressive stress and strain curves of ultra high performance concrete （UHPC） and flexural behavior of prestressed UHPC beams were conducted. It shows that the UHPC used in test has good deformation capacity. The strain at peak stress of UHPC is about 3 500× 10^-6 and ultimate strain is 4 500× 10^-6. The prestressed UHPC beams have good ductility and deformation capacity, and the ultimate deformation can be 1/42 to 1/34 of span. The predicted values of the failure modes, the crack and ultimate moment as well as ultimate are in good agreement with the test results. It stress of steel strands calculated by the proposed method verifies that the method has high precision.