盐渍土地区水泥基浆液最优配比及早期耐腐蚀性研究

Experimental study on optimal proportion and early corrosion resistance of cement-based slurry in saline soil region

针对西北盐渍土地区建筑地基注浆加固工程,选用水泥基注浆材料,对所选材料之间固化反应机理的可行性进行了分析。采用正交试验研究了不同配比下浆液的各项物理力学性能,对选出的最优配比浆液的浆液稳定性、粘度时变性和凝胶时间进行了试验,并且对最优配比浆液结石体和纯水泥浆液结石体进行了腐蚀溶液浸泡和SEM微观对比试验。结果表明:水灰比1.0,其他掺量占水泥的质量百分比分别为粉煤灰40%、Ca(OH)28%、无水硫酸钠7%和膨润土3%,浆液性能最优;最优配比浆液的密度1.658g/cm^3、3h析水率3%、结石率97%、初配漏斗粘度37s、7d(28d)抗压强度为7.20MPa(12.23MPa),均满足水泥基稳定浆液的要求;最优浆液的最佳注浆时间为90min;最优浆液结石体比纯水泥浆液结石体更密实,早期耐腐蚀性能更优。

For the project of grouting reinforcement in saline soil of northwest areas, the cement-based grouting materials are chosed and the feasibility of curing reaction mechanism among the selected materials is analyzed. The various physical and mechanical properties of different proportion of slurry are studied by orthogonal test. Among the optimal ratio of grout, the slurry stability, viscosity and gelation time are also tested. And the comparison test between the optimal ratio of slurry concretion and the pure cement slurry concretion is carried out through corrosion solution soaking and SEM microscopic. The results show that the water cement ratio is 1.0, and the percentages of other materials are that： the fly ash is 40% , the Ca （OH）2 is 8% , the anhydrous sodium sulfate is 7% and the bentonite content is 3%. The density of the slurry is 1. 658 g/cm3, the syneresis rate of the slurry is 3% , the concretion rate of the slurry is 97% , the viscosity timeliness of the slurry is 37s, the 7d （28d） compressive strength of the slurry is 7.20MPa （12.23MPa）. All indexes can meet the requirements of the cement stable slurry. The optimal grouting time of the slurry is 90min. The optimal grouting concretion is more dense than the pure cement slurry concretion, and the early corrosion resistance of the optimal grouting concretion is much better.