钙源和外加剂对微生物诱导碳酸钙沉积（MICP）的加固效果均有影响。为探索不同浓度外加剂（AlCl3?6H2O）和不同钙源联合作用对MICP固化效果的影响，开展砂柱试验和水溶液试验，在胶结液中加入不同浓度AlCl3?6H2O进行灌注试验，测试加固后砂柱的无侧限抗压强度和碳酸钙含量等。分析了钙源分别为氯化钙和醋酸钙的MICP加固效果，以及不同浓度AlCl3?6H2O对两种钙源下MICP加固效果的改进情况，并通过SEM分析了铝离子对碳酸钙成分及形态的影响。研究结果表明：醋酸钙为钙源的固化效果更佳；加入铝离子后，氯化钙为钙源的强度优化效果更明显；其中，6mmol/L的AlCl3?6H2O浓度为本研究条件下的最佳优化浓度，有利于减少灌注次数、节省原材料以及降低经济成本；铝离子有助于碳酸钙晶体的形成，增强砂颗粒的吸附性，实现固化强度的提升。氯化铝浓度对不同钙源下MICP固化效果有显著影响，对实际应用有重要意义。

Both calcium source and admixture have an effect on the reinforcement effect of microbial induced calcium carbonate precipitation (MICP). In order to explore the effects of different concentrations of admixtures (AlCl3?6H2O) and calcium sources on the curing effect of MICP, the sand column test and aqueous solution test were carried out, and different concentrations of AlCl3?6H2O were added to the cementing solution for perfusion test, and the unconfined compressive strength and calcium carbonate content after reinforcement were tested. The MICP reinforcement effect of calcium chloride and calcium acetate were analyzed, and the improvement of MICP reinforcement effect under different concentrations of AlCl3?6H2O under the two calcium sources was analyzed. The effect of aluminum ions on the composition and morphology of calcium carbonate was analyzed by SEM. The results showed that calcium acetate as the calcium source had a better curing effect. After adding aluminum ions, the strength optimization effect of calcium chloride as a calcium source is more obvious. Among them, the concentration of AlCl3?6H2O at 6mmol/L was the optimal concentration under the conditions of this study, which was conducive to reducing the number of perfusions, saving raw materials and reducing economic costs. Aluminum ions contribute to the formation of calcium carbonate crystals, enhance the adsorption of sand particles, and improve the curing strength. The concentration of aluminum chloride has a significant effect on the curing effect of MICP under different calcium sources, which is of great significance for practical application.

TU441.5；TU447

国家自然科学基金项目（51578214）