钢纤维再生混凝土劈拉强度试验研究

通过钢纤维再生混凝土立方体试件的劈拉强度试验,研究了钢纤维体积分数(0.0%～2.0%)、3种钢纤维类型(MF,SF,BF)、再生粗骨料处理方式以及试件尺寸变化对再生混凝土劈拉性能的影响.结果表明:钢纤维的加入显著提高了再生混凝土的劈拉强度,当纤维体积分数超过1.5%后,钢纤维再生混凝土的劈拉强度接近甚至超过天然钢纤维混凝土;钢纤维类型对再生骨料钢纤维混凝土影响显著,钢纤维对再生混凝土和天然混凝土的增强效果比较接近,其中BF钢纤维增强效果最好;尺寸效应对钢纤维再生混凝土的影响比天然钢纤维混凝土显著;再生骨料处理方法对钢纤维再生混凝土的劈拉强度也有一定的影响;现行钢纤维混凝土劈拉强度计算公式仍适用于钢纤维再生混凝土.

Experimental Research of the Splitting Tensile Strength of Steel Fiber Reinforced Recycled Concrete

The splitting tensile strength experiments of steel fiber reinforced recycled concrete specimens were employed for researching the influences of four various factors on the splitting tensile performance of recycled concrete,such as the volume fraction of steel fiber varying from 0.0% to 2.0%,three types of steel fiber with MF,SF and BF respectively,the different pretreatment methods of recycled coarse aggregate and various specimen sizes.The results showed that steel fiber could significantly improve splitting tensile strength of recycled concrete;when its volume fraction was more than 1.5%,the splitting tensile strength of steel fiber reinforced recycled concrete was close to or even more than that of natural steel fiber concrete;the splitting tensile strength of recycled aggregate concrete was affected by various types of steel fibers significantly and the result was similar to that of natural concrete,especially for the BF;the dimensional effect of steel fiber reinforced recycled concrete was more significant than that of natural steel fiber reinforced concrete.Besides,the splitting tensile strength of steel fiber reinforced recycled concrete also was affected by pretreatment methods of regenerated aggregate for steel fiber reinforced recycled concrete on splitting tensile strength.The current formula for calculating splitting tensile strength was still available for steel fiber reinforced recycled concrete.