灌浆缺陷对钢筋套筒动态连接性能的影响

Influence of Grouting Defects on Dynamic Connection Performance of Steel Sleeve

为了研究灌浆缺陷对钢筋套筒动态连接性能的影响,对22个带缺陷的钢筋套筒试件进行拉伸试验,分析缺陷类型、缺陷尺寸、加载速率对钢筋套筒试件连接性能的影响规律。结果表明:钢筋套筒的连接承载力与缺陷尺寸呈负相关,其中中部缺陷影响最大,端部缺陷次之,厚度缺陷最小;试件的粘结强度与钢筋的锚固长度l呈负相关,锚固长度每减小0.5 d,粘结强度平均增大0.9 MPa。试件的粘结强度与加载速率呈正相关,高速率试件粘结强度平均增大8%;随着钢筋与灌浆料滑移量的增大,两者之间的粘结力先增后减,呈现有规律的变化。最后归纳总结出考虑缺陷类型和加载速率的钢筋套筒粘结强度公式以及试验相关的钢筋与灌浆料的粘结强度-滑移曲线。

In order to study the influence of grouting defects on the dynamic connection performance of steel sleeve,tensile tests were conducted on 22 steel sleeve specimens with defects,and the influence of defect types,defect sizes,and loading rates on the connection performance of steel sleeve specimens were analyzed.The results show that there is a negative correlation between the connection bearing capacity of the steel sleeve and the defect size,with the central defect having the greatest impact,the end defect taking the second place,and the thickness defect being the smallest;the bond strength of the specimen is negatively correlated with the anchor length of the reinforcement,which increases by an average of 0.9 MPa for each 0.5 d decrease in the anchor length.The bond strength of the specimen is positively correlated with the loading rate,and the bond strength of the high-speed specimen increases by an average of 8%;with the increase of slip between the reinforcement and the grouting material increases,the cohesive force between the two increases first and then decreases,showing a regular change.Finally,the bond strength formula of steel sleeve considering defect type and loading rate and the bond strength-slip curve of steel bar and grouting material related to the test are summarized.