套筒水平灌浆缺陷复灌前后对套筒钢筋受拉性能的影响

Influence of Sleeve Horizontal Grouting Defects on Tensile Properties of Sleeve Reinforcement before and after Re-grouting

为检测灌浆套筒由于灌浆不密实对套筒钢筋的受力影响,设计制作了灌浆率为100%、80%、70%、60%的4组不同的套筒进行了拉伸受力试验来验证缺陷对受力的影响程度。结果表明:无缺陷灌浆套筒连接的屈服强度和抗拉强度均满足标准要求,和钢筋力学性质完全一致。对灌浆率为80%灌浆套筒连接的屈服强度能够满足标准要求,但时最大应力只相当于钢筋的屈服强度。对灌浆率为70%灌浆套筒连接未达到屈服强度就被拔出,最大强度仅为钢筋标准屈服强度的33%。对灌浆率为60%灌浆套筒钢筋加载初期就被拔出,最大强度仅为钢筋标准屈服强度的9%。采用高强无收缩灌浆料(GWL)和套筒高强灌浆料(TGL)进行复灌对比试验,采用GWL的套筒不能满足受力要求,其原因是流动性不能满足要求,采用TGL的套筒的力学性能满足规范要求,在工程检测中如发现灌浆缺陷,采用复灌方法是可以解决的,其中灌浆料的选择尤为重要。

In order to detect the influence of grouting sleeve on the stress of sleeve reinforcement due to the grouting compaction,four groups of sleeves with grouting rate of 100%,80%,70%and 60%were designed and manufactured to verify the influence of defects on the stress.The following results are got from the research.The yield strength and tensile strength of the defect-free grouting sleeve connection meet the standard requirements.They are completely consistent with the mechanical properties of the steel bar.For a grouting rate of 80%,the yield strength of the grouting sleeve connection can meet the standard requirements,but the maximum stress is only equivalent to the yield strength of the steel bar.When the grouting rate is 70%,the sleeve connection is pulled out before reaching the yield strength,and the maximum strength is only 33%of the standard yield strength of the reinforcement.When the grouting rate is 60%,the sleeve reinforcement is pulled out at the beginning of loading,and the maximum strength is only 9%of the standard yield strength of the reinforcement.Both the high strength non-shrinkage grouting material(GWL)and sleeve high-strength grouting material(TGL)were used for re-grouting comparative test.It is found that the sleeve with GWL can not meet the stress requirements,and the fluidity can not meet the requirements.The mechanical properties of the sleeve with TGL can meet the specification requirements.If grouting defects are found in the engineering inspection,the regrouting method can be used.In order to solve the problem,the selection of grouting materials is particularly important.