钢筋与钢纤维再生混凝土黏结滑移性能试验研究

Experimental study on bond-slip performance between steel and steel fiber recycled concrete

为研究钢筋与钢纤维再生混凝土的黏结滑移性能,共设计25组75块拉拔试件,研究了再生骨料取代率(0、30%、50%、70%、100%)和钢纤维体积掺量(0、0.4%、0.8%、1.2%、1.6%)对再生混凝土黏结滑移性能、抗压强度和劈拉强度的影响。结果表明:随着再生骨料取代率的增加,黏结强度、抗压强度和劈拉强度均呈下降趋势,但对滑移性能无明显影响。未掺钢纤维时,再生混凝土拉拔试件的破坏形态主要为劈裂破坏;钢纤维增掺入后,则主要呈现劈裂拔出破坏和拔出破坏。钢纤维的掺入改善了再生混凝土的抗压强度、劈拉强度以及钢筋与再生混凝土间的黏结滑移性能,再生骨料取代率为30%,钢纤维掺量为1.6%时的抗压强度和劈拉强度较基准混凝土分别提高了23.22%、12.72%;钢纤维掺量为1.2%时,其黏结强度最大,加载端滑移值随着钢纤维掺量的增加而增加。

In order to study the bond-slip properties of steel and steel fiber recycled concrete,25 sets of 75 specimens were designed,the effects of replacement ratio of recycled aggregate(0,30%,50%,70%,100%)and volume fraction of steel fiber(0,0.4%,0.8%,1.2%,1.6%)on bond-slip properties,compressive strength and splitting tensile strength were studied.The research shows that the bond strength decreases with the increase of replacement ratio of recycled aggregate,but it has no obvious effect on slip property,and the compressive strength and splitting tensile strength decrease as a whole.when the steel fiber content is 0,the damage form of the test piece is mainly the splitting failure,when the steel fiber content is not 0,the splitting-pulling out failure and the splitting failure mainly occur;the incorporation of steel fiber improves the bond-slip properties between steel and recycled concrete,when the steel fiber content is 1.2%,the bond strength is the highest.The compressive strength and splitting tensile strength of concrete with recycled aggregate replacement rate of 30%and steel fiber content of 1.6%are 23.22%and 12.72%higher than those of ordinary concrete,respectively.In the range of 0~1.6%,with the higher the steel fiber content,the slip value of load side is greater.