二次受力下钢筋RPC外包型钢梁的受弯性能

为探究新型材料对钢结构性能的增强效果，通过外包钢筋活性粉末混凝土（RPC）对受荷状态下的型钢梁进行加固并分析其受弯性能。通过二次受力下的抗弯试验，分析了钢筋RPC外包型钢梁的破坏过程和初始荷载、RPC强度、型钢强度对梁抗弯承载力的影响，并对试验结果进行了有限元模拟验证。结果表明：在不同参数影响下，外包钢筋RPC增强后的型钢梁与纯钢梁相比抗弯承载力提高17~2倍，破坏过程表现出良好的延性；受力过程中型钢与RPC界面未发生黏结破坏，两者能够共同工作；钢筋RPC外包型钢梁的极限承载力随初始荷载的增大而减小，随RPC强度和型钢强度增大而增大。根据试验结果，提出了二次受力下钢筋RPC外包型钢梁受弯承载力计算公式以及RPC强度折减公式，试验值、计算值和模拟值三者吻合良好。

Flexural behavior of reinforced RPC wrapped steel beams under secondary loading

In order to explore the enhancement effect of new materials on the performance of steel structures, the flexural behavior of steel beams under load is analyzed by strengthening and transforming the steel beams with Reinforced Reactive Powder Concrete (RPC). Through the bending test of the test beam under the secondary load, the failure process of the beam was analyzed. Then, the influences of initial load, RPC strength, and section steel strength on the bearing capacity of beam were studied. The test results were verified by the finite element simulation. The research shows that under the influence of different parameters, the bending capacity of the steel beam wrapped by reinforced RPC is 1.7~2 times higher than that of the pure steel beam and the specimen shows better ductility during the failure process. Meanwhile, no bond failure occurs at the interface between the section steel and the RPC, and both can work well together. The ultimate bearing capacity of the beam decreases with the increase of the initial load and increases with the increase of RPC strength and section steel strength. According to the experimental results, the calculation formula for the flexural bearing capacity of steel beam wrapped by reinforced RPC under the secondary load and the RPC strength reduction formula are proposed. The experimental value, the calculated value and the simulated value are in good agreement.