钢纤维再生混凝土的直剪力学性能

Mechanical Properties of Steel Fiber Reinforced Recycled Aggregate Concrete under Direct Shear

为研究直剪作用下钢纤维再生混凝土(SFRAC)的破坏机理,以试件尺寸、再生骨料取代率、钢纤维体积分数V为变化参数,设计了138个试件,并对其进行了直剪试验,得到了试件的直剪荷载-位移全过程曲线,分析了不同变化参数对SFRAC峰值剪力、抗压强度等直剪力学性能的影响规律,给出了不同试件尺寸下SFRAC峰值剪力的换算系数,提出了SFRAC抗剪强度公式.结果表明:随着试件尺寸的增大,SFRAC峰值剪力逐渐增大;随着再生骨料取代率的增加,V=0%的试件峰值剪力先增大后减小,V=1.0%的试件峰值剪力减小;钢纤维对再生混凝土抗剪能力提高幅度较大,对抗压强度提高幅度较小;提出的抗剪强度公式计算值与试验值吻合良好.

In order to study the mechanical properties of steel fiber reinforced recycled aggregate concrete(SFRAC)under direct shear,138 specimens were designed and tested with the change parameters of specimen size,substitution rate of recycled aggregate and steel fiber volume fraction(V).The whole process curves of direct shear load-displacement of specimen were obtained,and the influence rules of different variation parameters on peak shear force and compressive strength of steel SFRAC were analyzed.The conversion coefficient of SFRAC peak shear forces under different specimen sizes was obtained,and the shear strength formula of SFRAC was proposed.The results show that the peak shear force of SFRAC increases with the increase of specimen size.With the increase of V,the peak shear force of specimens with V=0%first increases and then decreases,and the peak shear forces of specimens with V=1.0%decreases.Steel fiber can improve the shear capacity of recycled concrete greatly,but it can only improve the compressive strength slightly.The calculated values of the proposed shear strength formula are in good agreement with the experimental values.