侧向约束下后浇再生混凝土与旧混凝土交界面抗剪强度研究

Study on Shear Strength of Interface between Post-cast Recycled Concrete and Old Concrete under Lateral Constraint

为研究钢套管再生混凝土柱中的后浇再生混凝土与旧混凝土交界面的工作性能,本试验共制作10个推出型试件测试后浇再生混凝土与旧混凝土交界面的抗剪强度。为模拟钢套管对后浇再生混凝土的约束作用,对其中6个试件采用螺栓连结的钢板施加侧向约束。研究变量包括再生骨料的取代率及侧向压力大小。试验结果表明,侧向约束压力可以有效提高新旧混凝土交界面的抗剪强度和变形能力,使交界面的黏结力得到充分发挥。在水灰比相同的条件下,交界面抗剪强度随再生骨料取代率的增大而提高。

In order to study the cooperative performance of interface between old concrete and post-cast recycled concrete in steel-jacket retrofitted column with recycled aggregate concrete,the shear transfer capacity of the cold-joint interface of 10 push-off specimens were tested.In order to simulate the restraint effect of steel casing on post-pouring recycled concrete,lateral restraint was applied to bolted steel plates for 6 specimens.The major test variables included the recycled coarse aggregate(RCA)replacement ratio and the lateral pressure.The results indicate the presence of the lateral pressure can improve the shearing strength as well as deformation capability greatly and the bonding action of the interface can be fully exerted under lateral restraint.According to the test results,some conclusion can be drawn:under the same water-cement ratio,the shearing strength of the interface increases with the increase of the replacement rate of recycled aggregates.