(1 长沙市建筑设计院有限责任公司, 长沙 410007; 2 湖南科技大学土木工程学院, 湘潭 411201;3 江西省标正技术工程有限公司, 南昌 330077)

摘要: 目前混凝土结构裂缝化学注浆主要是针对平滑等宽的收缩类裂缝,注浆孔往往沿裂缝开展深度方向等距布置,这对于不等宽的受力裂缝常导致在表面溢浆的同时,内部未能有效封堵的质量问题,严重影响注浆效果. 为此,对钢筋混凝土梁进行了反向加载试验,研究了受弯裂缝宽度沿截面高度的变化规律,提出了钢筋对受弯裂缝开展的有效约束范围为 5. 9d(d 为钢筋直径),建立了考虑钢筋约束作用的受弯裂缝宽度模型;结合环氧浆液扩散半径理论公式,提出了混凝土受弯裂缝的最佳钻孔深度为距表面 0. 60H(H 为裂缝沿截面开展的总高度),该注浆孔位置可实现受弯裂缝表面溢浆的同时,内部亦能有效封堵的预期效果.

关键词: 混凝土; 钢筋约束作用; 注浆; 受弯裂缝; 钻孔; 平滑等宽

中图分类号:TU375 文献标志码:A 文章编号:1002-848X(2023)10-0128-06

DOI:10. 19701 / j. jzjg. LS220036

Research on grouting repair technology for concrete flexural cracks based on rebar restraint

WANG Meng1, LÜ Weirong2, YIN Guolin2, LU Beirong2, ZHONG Xiaojin3, WU Jidong2

(1 Changsha Architectural Design Institute Co. , Ltd. , Changsha 410007, China; 2 Department of Civil Engineering,Hunan University of Science and Technology, Xiangtan 411201, China; 3 Jiangxi Standard Technology EngineeringCo. , Ltd. , Nanchang 330077, China)

Abstract: At present, chemical grouting of cracks in concrete structures is mainly aimed at shrinkage cracks of smooth andequal width, and grouting holes are often arranged equidistant along the depth direction of cracks, which often leads to thesurface grouting overflow while the internal quality problem is not effectively blocked for cracks of unequal width, whichseriously affects the effect of grouting. Therefore, the reverse loading test of reinforced concrete beam was carried out, andthe law of bending crack width changing along the section height was studied. The effective constraint range of steel bar onbending crack was proposed to be 5. 9d (d is the diameter of steel bar), and the bending crack width model considering theconstraint effect of steel bar was established. Combined with the theoretical formula of diffusion radius of epoxy grout, it isproposed that the optimal drilling depth of concrete bending crack is 0. 60H from the surface (H is the total height of thecrack along the section). The grouting hole position can realize the expected effect of grouting overflow on the surface ofbending crack and effective plugging inside.

Keywords:concrete; rebar restraint; grouting; flexural crack; drilling; smooth and equal width

∗国家自然科学基金面上项目(51578235),湖南省研究生科研创新项目(CX20210993).

第一作者:王猛,硕士,高级工程师,一级注册结构工程师,主要从事工程结构设计,Email:31747603@ qq. com.

[引用本文] 王猛,吕伟荣,尹国林,等. 基于钢筋约束作用的混凝土受弯裂缝注浆修复技术研究[ J]. 建筑结构,2023,53(10):128-133. WANG Meng,LÜ Weirong,YIN Guolin,et al. arch on grouting repair technology for concreteflexural cracks based on rebar restraint[J]. Building Structure,2023,53(10):128-133.