超高性能混凝土板加固足尺钢筋混凝土梁抗剪性能

Shear Behavior of Full-scale Reinforced Concrete Beams Strengthened with Ultra-high Performance Concrete Plates

为进一步研究超高性能混凝土(ultra-high-performance concrete,UHPC)预制板加固钢筋混凝土(reinforced concrete,RC)梁的抗剪性能,开展了3根足尺RC梁的试验研究,包含1根对比梁和2根UHPC预制板加固梁,关注UHPC板及其内嵌CFRP板条对RC梁抗剪性能的影响。试验结果表明:试验梁均发生受剪破坏,但加固梁的承载力、刚度和延性均明显提高,其中,因内嵌CFRP板条提高了UHPC板的抗裂性能,极限荷载及对应位移分别提高了30.8%和28.5%;螺杆力学锚固发挥了侧向约束作用和销栓作用,在一定程度上提高了UHPC板的贡献。同时,通过建立非线性有限元模型对试验梁进行了数值分析,模拟结果与试验结果吻合度高,表明模型所选的本构关系及相关参数合理,可用于预测UHPC板加固RC梁的全过程受力行为。

In order to further study the shear behavior of reinforced concrete(RC)beams strengthened with ultra-high-performance concrete(UHPC)plates,an experimental study was carried out on three full scale RC beams,including a control one and two ones strengthened using UHPC plates with or without CFRP strips.The effects of UHPC plates and CFRP strips were focused.The test results show that the shear failure occurs in all the test beams,but the bearing capacity,stiffness and ductility of the reinforced beams are significantly improved.Among them,the cracking resistance of UHPC plates is improved by embedded CFRP strips,and the ultimate load and corresponding displacement are increased by 30.8%and 28.5%,respectively.The screw mechanical anchorage plays the role of lateral restraint and pin,which improves the contribution of UHPC plate to a certain extent.At the same time,a nonlinear finite element model is established to analyze the test beam.The simulation results are in good agreement with the test results,indicating that the constitutive relationship and related parameters selected in the model are reasonable and can be used to predict the whole process stress behavior of RC beams reinforced by UHPC plates.