型钢混凝土不同界面的黏结性能及锚固设计

Anchorage Design Method and Interfaces Bond Behavior of Steel Encased Concrete Member

为了研究不同界面型钢混凝土的自然黏结性能,设计4个试件进行静力单调推出试验,试件分别考虑了型钢外翼缘、内翼缘、腹板以及全截面与混凝土黏结时的4种不同情况,通过试验观察了各试件的受力破坏过程和形态,获取了荷载-滑移曲线、极限黏结强度等参数,分析了型钢不同界面与混凝土的黏结强度;此外,为了深层次研究型钢混凝土构件的黏结锚固性能,设计了3个焊接栓钉的型钢混凝土试件进行静力单调推出试验,试件分别考虑了栓钉仅焊接在型钢外翼缘、腹板、以及外翼缘和腹板均焊接3种不同情况,获取了焊接栓钉后型钢混凝土试件的黏结滑移性能,分析了不同位置处焊接栓钉对型钢混凝土黏结性能的影响,最后分别推导并建立了型钢混凝土构件仅考虑自然黏结以及焊接栓钉时的最小锚固长度计算公式.研究结果表明,不同界面型钢混凝土的自然黏结强度不相等,腹板处黏结强度最小,外翼缘次之,内翼缘最大,三者的比例关系为1∶1.39∶1.59;栓钉焊接位置对黏结性能有影响,腹板处焊接栓钉比在翼缘处焊接栓钉试件的延性更好.

In order to research the natural bond performance between steel and concrete with different interfaces in steel encased concrete structure,four specimens were designed to launch a test under the monotone push-out loading. Four conditions were considered in this test,including steel outer flange,inside flange,web and whole side bonding with the concrete. Failure process and modes of these specimens were obtained. Load-slip curves and ultimate bond strength were obtained and the different interfaces bond strength between steel and concrete were analyzed.Besides,three specimens with studs in steel were fabricated to deeply research the bond anchorage performance of steel encased concrete member. Three specimens with studs welded in steel,including studs welded in steel outer flange,steel web and outer flange uniting with web,were respectively considered. The bond and slip behaviors of steel encased concrete specimens with studs were obtained and studs locations influence on the bond behavior of steel encased concrete was analyzed. Finally,the minimum anchorage length calculation formulas were established under the conditions of natural bond,steel with studs,respectively. The results show that different interfaces bond strengths of steel encased concrete members are not equal. The bond strength in steel web is the minimum,while the bond strength in inside flange is the maximum. Studs welded locations influence on bond strength a bit,the contrast results show that specimens ductility with studs in web is much better than that in flange.