Effects of multi-nutrient treatment on the uniformity and strength of MICP-cemented sand
Wang Xuming , Guo Wei , Yu Fei , Yi Zhao , Sun Lin
DOI:10.11835/j.issn.1674-4764.2017.03.019
Received September 10, 2016,Revised , Accepted , Available online July 04, 2017
Volume ,2017,Pages 145-150
- Abstract
The MICP(microbial induction of calcium carbonate precipitation)cemented sand samples are prepared by injecting twice bacteria solution with different concentrations of nutrient salt treatment. S. pasteurii is used to induce calcite precipitation, and all the specimens were prepared by injecting a single concentration or multi-concentration nutrient solutions. In this study, 0.5 and 1.0 mol/L urea-calcium chloride solutions are used for the former grouting treatment, while for the latter one, 0.5 mol/L urea-calcium chloride solution is firstly injected; and subsequently, 1.0 mol/L urea-calcium chloride solution is utilized. Based on the experiment, the strength, modulus of elasticity and calcite content of MICP specimens' different sections are analyzed. From the experimental results, it can be found that multi-concentration nutrient treatment has significant influence on the unconfined compressive strength of bio-cemented sand and calcite content. The multi-concentration nutrient treatment can ensure the high strength and elastic modulus of the sample under the condition of good uniformity. Finally, the basic factors that affect the strength and uniformity of samples were discussed based on the method of multi-concentration nutrient treatment.