波纹管成孔钢筋约束浆锚搭接连接力学性能

Mechanical Properties of Deformed Rebars Lapped in Spiral Stirrups Confined Grout-Filled Corrugated Pipes

为验证预埋波纹管成孔钢筋约束浆锚搭接连接的可靠性,设计制作了60组、共180个接头试件并进行了单向拉伸试验,试件参数包括纵筋直径、混凝土强度、螺旋箍筋直径和螺距。结果表明:所有试件的抗拉强度与钢筋屈服强度标准值的比值均大于1.5,与钢筋抗拉强度标准值的比值大于1.1。对于直径10 mm和12 mm的接头试件,螺旋箍筋构造对接头抗拉强度的影响不明显。对于直径14 mm的试件,螺旋箍筋体积配箍率越大,箍筋螺距越小,混凝土损伤越小。在配箍率相差不大的情况下建议选择较小的箍筋直径和螺距。当螺旋箍筋配置为d4@50,纵筋公称直径≤14 mm时,搭接长度可取钢筋基本锚固长度。

60 sets of 180 specimens were designed and manufactured to verify the reliability of the splice in which the rebars lapped in spiral stirrups confined grout-gilled corrugated pipes.The specimen parameters include longitudinal reinforcement diameter,concrete strength,and spiral rebar diameter and screw pitch.The monotonic tension loading test results indicated that the ultimate tensile strength of specimens all exceeded the 150 percent of the specified yielding strength and 110 percent of specified tensile strength of the lapped rebars.For the splice specimens with lapped rebar diameters of 10 mm and 12 mm,the effect of the spiral stirrups on the tensile strength of the splice specimens was not obvious.For the specimens with a rebar diameter of 14 mm,larger volume ratio and smaller screw pitch of the spiral stirrups could result in less damage of the concrete block under tension load.For a similar reinforcement ratio,it was recommended to use a smaller rebar diameter and screw pitch.When the spiral configuration was d4@50 and the nominal diameter of the longitudinal reinforcement was not more than 14 mm,the lap length could be taken as the basic anchorage length of rebar.