CFRP筋在活性粉末混凝土中的锚固性能

针对碳纤维增强塑料CFRP(Carbon Fiber Reinforced Polymer/Plastics)作为预应力筋或拉索时的锚固问题,提出了以活性粉末混凝土RPC(Reactive Powder Concrete)作为粘结介质的粘结式锚具.静载试验详细研究了CFRP筋的表面形状、锚固长度、根数和间距以及套筒内壁倾角等参数的变化对RPC的锚固性能的影响.试验结果表明,CFRP筋的表面形状对锚固性能的影响最为显著;对于抗拉强度不大于3 000 MPa的表面压纹CFRP筋,其临界锚固长度约为20倍CFRP筋直径;双根压纹CFRP筋锚固时的合理筋间距不宜小于1倍CFRP筋直径;本文提出的平均粘结强度和临界锚固长度计算公式具有较好的适用性.

The Anchorage Behavior of CFRP Tendons in RPC

One of the obstacles for CFRP(Carbon Fiber Reinforced Polymer/Plastics) bar to be widely used as tendon and cable in civil engineering is the methodology to its anchor.The ultra high performance concrete RPC(Reactive Powder Concrete) has been put forward as the bond medium,and a series of tests have been carried out to develop a new bond-type of anchorage system for CFRP tendon and cable.Those parameters of surface shape,bond length,number and space of CFRP tendons and the slope of inner wall of outer steel tube used in the anchorage system have been studied.The test results have shown that the surface shape of CFRP tendon is significant to the anchor behavior of CFRP tendon in RPC.The grouted length of 20 diameters of CFRP tendon is enough for the indented surface CFRP tendon of tensile strength less than 3 000 MPa.The appropriate rod space is not less than the rod diameter for the anchorage system with two CFRP tendons,and the equations developed to determine the bond capacity and the critical bond length between CFRP tendon and RPC are feasible.