新老混凝土结合面抗剪性能试验研究

Experimental Study of Shear Performance of New-to-old Concrete Interface

新老混凝土结合面是加固结构中最脆弱的部位,新老混凝土能否正常工作主要取决于结合面的抗剪强度。通过模型试验对结合面抗剪性能进行了研究。模型采用Z型试件,分为凿毛不植筋和既凿毛又植筋两种。对比试验结果表明,植筋能大大改善结合面的抗剪性,且大幅度提升新结构的承载力,是一种有效的加固处理方法。数值仿真结果与试验结果比较表明,结合面加固处理的模拟能在一定程度上反映实际情况中结合面的力学性能。

New-to-old concrete interface is the most vulnerable part of reinforcement structure.The carrying capacity of new-to-old concrete mainly depends on the shear strength of new-to-old concrete interface.Shear performance of joint interface was studied through the model experiment.The tested model is Z type specimens,which are divided into two groups：scabbling without embedded reinforcing bar and scabbling with embedded reinforcing bar.Comparison of experimental results shows that embedded reinforcing bar can greatly improve shear resistance of joint interface and greatly enhance the carrying capacity of new structure.So it is an effective method of reinforcement.The comparison between numerical simulation and experimental results indicate that the simulation for joint interface reinforcement can reflect at certain extent the practical mechanical properties of new-toold concrete interface.