钢纤维对高强钢筋RPC无腹筋梁的剪切性能影响研究

STUDY ON THE EFFECT OF STEEL FIBER ON SHEAR PERFORMANCE OF HIGH-STRENGTH REINFORCED RPC BEAMS WITHOUT STIRRUPS

为研究无腹筋高强钢筋活性粉末混凝土简支梁的剪切性能,基于集中荷载下4根RPC梁受剪破坏试验的结果,以钢纤维体积率为主要研究参数,分析钢纤维体积率对梁的斜裂缝发展形态、荷载-挠度曲线、剪切韧性及斜裂缝宽度的影响。结果表明:钢纤维能够减小斜裂缝间距,增加剪压区高度,改善梁的剪切延性;钢纤维对梁受荷初期的剪切韧性影响较小,而对初始屈服点后梁的剪切韧性影响较大;钢纤维体积率越大,斜裂缝宽度越小,峰值荷载越大,且其对峰值荷载的影响较对跨中挠度的影响显著。

To study the shear performance of high-strength reinforced reactive powder concrete simply supported beams without stirrups, based on the test results of four RPC beams＇ shear failure experiment under concentrated load, the influence of steel fiber volume ratio on diagonal crack development pattern, load-deflection curves, shear toughness of beams and diagonal crack width is analyzed. Results show that steel fiber can reduce the diagonal crack spacing, increase the shear-compression zone height, and improve the shear ductility of the beam. Steel fiber has less effect on shear toughness of beams at the initial stage of loading, but it has great effect on shear toughness of beams after the initial yield point. The greater the steel fiber volume ratio is, the smaller the diagonal crack width and the greater the peak load are. Its influence on peak load is more obvious than the effect on mid-span deflection.