早期振动对钢筋套筒灌浆连接受力性能影响的试验研究

Experimental research on the influence of early vibration on mechanical behavior of grout sleeve splicing for rebars

钢筋套筒灌浆连接作为装配式混凝土建筑中竖向钢筋的主要连接方式得到广泛应用,但灌浆料凝固期内,振动环境对钢筋套筒灌浆连接性能影响的研究很少。为研究早期振动对钢筋套筒灌浆连接性能的影响,对其进行了试验研究。试验制作了15组试件,对3组钢筋直径20mm、振幅0.3mm、频率2Hz的连接试件进行单向拉伸试验、高应力反复拉压试验和大变形反复拉压试验,对其他12组试件进行单向拉伸试验。试验结果均为接头外钢筋拉断破坏,接头连接性能满足规范要求。试验表明不同振幅时,连接试件的荷载-变形曲线大致相同,连接试件的极限变形随振幅增大略有增加;振动频率的变化对连接试件的受力性能影响很小;相同应力条件下,大直径钢筋的连接试件变形大于小直径钢筋。试验的振动加载方式引起了连接钢筋在套筒内偏置,但在此偏心的不利影响下,套筒灌浆连接试件性能仍满足规范要求。

As the main connection mode of vertical reinforcement in fabricated concrete buildings,grout sleeve splicing for rebars has been widely used.However,there is little research on the influence of vibration environment on the grout sleeve splicing during the solidification period of grouting material.In order to study the effect of early vibration on the properties of grout sleeve splicing for rebars,an experimental study was carried out.Fifteen groups of specimens were made,and unidirectional tensile test,high stress and large deformation repeated tension-compression test were carried out on three groups of connecting specimens with 20mm diameter of rebars,0.3mm amplitude and 2Hz frequency,the other twelve groups of specimens were tested by unidirectional tensile tests.The test results show that the specimens are broken outside the joint and the connection performance meet the requirements of the specification.The test results show that the load-deformation curves of the specimens are roughly the same at different amplitudes,and the limit deformation of the joints increases slightly with the increase of amplitude.The change of frequency has little effect on the mechanical properties of the specimens.Under the same stress condition,the deformation of large-diameter steel connecting specimens is larger than that of small-diameter steel connecting specimens.The vibration loading mode in the test causes the steel bar to be biased in the sleeve,but the performance of grout sleee splicing connecting specimen still meets the requirements of the specification under the adverse influence of the eccentricity.