高抗渗注浆材料研究

Study on High Anti-permeability Grouting Material

为提高围岩的抗渗性能,采用普通水泥浆液掺加无碱外加剂制备高抗渗注浆材料。试验结果表明,在水灰比0.65~1.0范围内,调整浆液配合比,浆液流动度可达到230 mm^270 mm,初凝时间小于2 h,具有良好的施工性能;注浆材料结石体早期强度发展快,后期强度高且无倒缩现象。注浆材料具有微膨胀特性,内部孔径细化,具有良好的抗渗性能,抗渗等级大于P8,满足工程抗渗需求。

Cement-based grouting material is used to reinforce surrounding rocks of the subsea tunnel from Xiamen to Xiang＇an. In order to improve the anti-permeability of the grouting material, alkali-free admixtures were mixed into the cement grouting material and the performance of materials was studied. Water cement ratio （w/c）, the mixing amount of setting accelerator and water reducing agent were adjusted in the experiments, and the results showed that the initial setting time of the grout is less than 2 h while the grout flow ability ranges from 230 mm to 270 mm which indicating good workability. The grouting materials are characteristic of high early strength, stable long-term strength and micro dilatancy performance. The permeability grades of grouting materials （ with the w/c of 0.65, 0. 8 and 1.0, respectively） are higher than PS, which superiors to the contrast sample with no admixture. The improvement of anti-permeability is due to the thinning of pore size of grout stone.