焊接栓钉型钢混凝土梁抗扭性能试验研究

Experimental investigation on anti-torsion performance of welded stud steel reinforced concrete beams

为研究焊接栓钉型钢混凝土(SRC)梁的抗扭性能,设计了一套加载装置,完成9个试件的纯扭加载试验(其中焊接栓钉SRC试件7个,非焊接栓钉SRC和普通钢筋混凝土对比试件各1个),考虑了栓钉位置、长度、直径和间距4个变化参数。通过试验,观察试件的受力破坏过程及形态,获取裂缝分布情况、扭矩-扭率曲线、开裂扭矩和极限扭矩等数据,分析各变化参数对其受力性能的影响规律。结果表明:纯扭作用下,SRC梁试件表面出现螺旋状裂缝而破坏,焊接栓钉试件较普通SRC试件,其螺旋裂缝细而密、承载力更高、延性更好;栓钉焊接在型钢腹板较焊接在翼缘更有利于提高抗扭性能;栓钉长度和直径对其受扭性能有一定影响,适当增大长度和直径能提高其抗扭承载力;最后提出改进叠加法的计算公式,计算值与试验值吻合良好。

In order to reveal the anti-torsion performance of welded stud steel remtorcecl concrete I,~Kt~） oeams, a set of test device was designed, and nine specimens （including seven welded stud SRC specimens, one traditional SRC specimen and one reinforced concrete （RC） specimen） were prepared for the experimental study. In this work, the results of an experimental study of anti-torsion behavior of SRC beams under pure torsion are presented. Four parameters： the welded stud＇s location, spacing, stud＇s diameters and lengths were considered in the test. The effects of these parameters on the cracks, failure modes, torque-torsion ratio curves, ultimate torsion bearing capacity were discussed. The results demonstrate that all of specimens fail after the appearance of spiral cracks, and welded stud SRC specimens have more fine and dense cracks, higher anti-torsion bearing capacity and better ductility than the normal SRC specimen. Studs welded in web have better anti-torsion performance than in flange, and within a certain range, increasing the stud＇s length and diameter can improve the anti-torsion performance of specimens. In the end, the calculation method of improved superposition was proposed, and the calculation values agree well with the test results.