预制与后浇混凝土粘结后的动态劈拉性能

Dynamic Splitting Tensile Performance of Post Pouring Concrete Adhered on Precast Concrete

摘要:

为研究预制与后浇混凝土粘结后混凝土试件的动态劈拉性能，采用74变截面分离式霍普金森压杆（SHPB）装置，在不同应变率下，对粘结面粗糙度类型不同的试件进行了动态劈拉试验.结果表明：预制与后浇混凝土的动态劈拉强度和动态增大系数均表现出较强的应变率效应；预制与后浇混凝土的动态劈拉应力应变曲线可分为弹性阶段、屈服阶段和破坏阶段；混凝土试块出现了径向劈裂、径向与粘结面均劈裂这2种主要破坏形态；试件粘结面粗糙度越大，其动态劈拉应力应变曲线中屈服台阶越明显，其动态劈拉强度也越大，表现出明显的延性特征.

Abstract:

In order to investigate the dynamic splitting tensile performance of post pouring concrete adhered on precast concrete, a 74 variable cross section split Hopkinson pressure bar（SHPB） apparatus was used to conduct dynamic splitting tensile test with various strain rates for post pouring concrete adhered on precast concretes with different interfacial roughness. The results show that there is a significant effect of strain rate on dynamic splitting tensile strength and dynamic increase factor of post pouring concrete adhered on precast concrete. Dynamic splitting tensile stress strain curves of post pouring concrete adhered on precast concrete can be divided into elastic stage， yield stage and failure stage. Specimen failure patterns include radial and bonding surface splitting, block radial splitting. With the increase of the interfacial roughness, the yield step in specimen dynamic splitting tensile stress strain curve is more obvious, which reflects the significant ductility features, and the dynamic splitting tensile strength of post pouring concrete adhered on precast concrete is improved.