混凝土裂缝修补结构力学相容性研究

Experimental study on mechanical compatibility of concrete crack repair system

基于混凝土裂缝修补结构是否具有较好的力学相容性是修补效果好坏的关键。选取水泥净浆、纯聚合物、聚合物水泥净浆3种修补材料,通过一系列力学试验对混凝土裂缝修补结构的力学相容性进行探讨与研究。对比斜剪、劈拉、抗折以及组合梁抗折强度试验这4种试验方法,采用组合梁抗折强度试验方法能较为可靠有效地反映混凝土裂缝修补结构的力学相容性,用组合梁抗折强度比及其破坏形态来评价修补材料与基体的力学相容性也较为合适。研究结果表明:当保持这3种修补材料的3 d抗压强度在同一水平时,纯聚合物的其他力学性能包含"抗折强度、抗折黏结强度、抗拉强度、压折比"等的综合性能最优,并且用纯聚合物作为修补材料的混凝土裂缝修补结构的力学相容性也最好。

The key failure mechanism of concrete crack repair system is the poor compatibility between repair material and substrate concrete.With three different types of repair materials,i.e.,the cement paste,straight polymer and polymer cement paste,the mechanical compatibility of concrete crack repair structure was studied by a series of mechanical tests.By comparing the results of the shear tests,splitting tensile tests,flexural strength tests and composite beam flexural strength tests,it was found that the composite beam flexural strength test is more reliable and effective for evaluating the mechanical compatibility of concrete crack repair structures.It is also suitable to evaluate the mechanical compatibility by combining beam flexural strength ratio and fracture characteristics.The results indicate that when maintaining the 3-day compressive strength of these three different repairing materials at the same level,the other mechanical properties of the pure polymer including“flexural strength,flexural bond strength,tensile strength,and crimp ratio”show their optimum values,and the mechanical compatibility of cracked concrete structure repaired by polymer was also the best.