高应力反复拉压作用下堆焊成型套筒灌浆连接性能试验研究

Experimental study on performance of grouted sleeve connection with surfacing forming under high stress repeated tension-compression load

为研究钢筋套筒灌浆连接在高应力反复拉压作用下的受力性能及工作机理,采用堆焊成型套筒及开槽钢筋设计制作了4个接头试件,对其进行高应力反复拉压试验和单向拉伸对比试验。结果表明:接头试件在20次高应力反复拉压后残余变形约为0.1 mm,接头具有较为稳定可靠的使用性能;高应力反复拉压作用对接头的破坏形态和承载力基本无影响,对接头的变形性能有一定影响,钢筋屈服前刚度降低约40%,拉断时伸长率约增加26%;套筒端部区段钢筋的应变分布曲线在拉、压阶段明显不同。经20次循环后,套筒端部区段钢筋在最大拉载时的应变值趋于一致;高应力反复拉压作用对套筒的轴向应变和环向应变基本无影响,钢筋屈服前套筒的约束效果不明显。

In order to study the mechanical properties and working mechanism of grouted sleeve connection under the high stress repeated tension-compression action,four splice specimens were designed and manufactured by using sleeves with surfacing welding and slotted rebars.The high stress cyclic loading test and uniaxial tensile test were carried out.The results show that the residual deformation of specimens is about 0.1 mm after 20 cycles.The splice has a relatively stable and reliable performance.The high stress repeated tension-compression has no effect on the failure mode and bearing capacity of the splice,but has a certain influence on the deformation performance of the splice.The stiffness of the splice before rebar yielding is reduced by about 40%,and the elongation at failure is increased by about 26%.The strain distribution curve of the steel rebar in the sleeve end section is obviously different under tension and compression.After 20 cycles,the strain values of the rebars in the sleeve end section tend to be the same under the maximum tension load.The high stress repeated tension-compression has no effect on the axial strain and circumferential strain of the sleeve.The restraint effect of the sleeve before the rebar yielding is not obvious.