MgO膨胀剂在地下室结构自防水工程的应用研究

Research on application of MgO expander in structural self-waterproofing underground concrete engineering

为提高地下室混凝土结构防水效果和延长使用年限,提出采用结构自防水的建议。依托湖北黄冈某地下工程,采用MgO膨胀剂配制混凝土并以水泥基渗透结晶防水涂料作为外防水层的结构自防水做法。结果表明:混凝土内部应变为正值,处于微膨胀状态,MgO膨胀剂可以有效控制混凝土的开裂风险,达到良好的抗裂效果;水泥基渗透结晶型防水涂料能与混凝土中的Ca2+络合物发生反应生成难溶的沉淀产物,堵塞体系中的裂缝和孔隙,提高混凝土的防水抗渗性能;采用该结构自防水做法还可缩短工期。

In order to improve the waterproofing effect and prolong the service life of the basement structure,the self-waterproofing of the structure is proposed.In this paper,based on an underground project in Huanggang,Hubei Province,MgO expansion agent was used to prepare waterproof concrete and cement-based permeable crystalline waterproof coating was used as the outer waterproof layer.The results show that the internal strain of concrete set is positive and in the state of slight expansion.MgO expansion agent can effectively control the cracking risk of concrete and achieve good anti-cracking effect.Cement-based permeable crystalline waterproof coating can react with Ca2+complex in concrete to produce insoluble precipitates,plug cracks and pores in the system,and improve the waterproof and impermeability of concrete.The self-waterproofing method of the structure can shorten the construction period.