灌浆料对钢筋套筒灌浆连接性能影响

Effect of grout on connection performance of grout sleeve splicing for rebars

设计了4组不同水胶比和3组不同有机纤维掺量的套筒灌浆料,并考察了其对钢筋套筒连接接头拉伸性能的影响。结果表明,偏置单向拉伸试件破坏时断于钢筋所需的临界钢筋锚固长度大于对中单向拉伸试件,分别为7d和6d;膨胀剂的掺入显著降低了套筒灌浆料的自收缩,提高了钢筋套筒连接接头的拉伸强度;套筒灌浆料的劈拉强度与对中单向拉伸接头抗拉强度存在明显相关性,通过拟合建立了二者的换算公式,且计算值与实测值吻合较好。

Four groups of sleeve grouting materials with different water-binder ratios and three groups of different organic fiber content were designed,and their influence on the tensile properties of steel sleeve connecting joints was investigated.The results showed that the critical anchorage length of reinforcement required for a biased uniaxial tensile specimen(7d),when the fracture occurred at the steel bar,was longer than that required for the centering unidirectional tensile specimen(6d).The use of expansion agent significantly reduced the autogenous shrinkage of grouts,and thus improved the tensile strength of the connecting joint.Besides,a good relationship can be established between the split tensile strength of grouts and the tensile strength of the centering unidirectional tensile joint.The conversion formula of the two is established by fitting,and the calculated value is in good agreement with the measured value.