Experimental study of synergistic reinforcement of silty clay with glutinous rice paste and MICP

• Published in: PLOS ONE
• Main Authors: Hu, Qizhi, Chen, Qian
• Other Authors: Barakat, Nasser A. M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2023
• Subjects: Carbonic acid
• Online Access: http://dx.doi.org/10.1371/journal.pone.0284633; https://dx.plos.org/10.1371/journal.pone.0284633

The use of microbially induced calcium carbonate precipitation (MICP) technology can improve the mechanical properties of silty clay, and glutinous rice paste can enhance microbial activity, improve the conversion rate of CaCO 3 precipitation, and help increase soil strength. An MICP solidification test of silty clay was carried out by adding different concentrations of aged glutinous rice slurry and cementing liquid, and unconfined compressive strength tests and scanning electron microscope analysis of the solidified samples were carried out. The strength growth mechanism of the glutinous rice paste was investigated, and the results revealed that glutinous rice slurry can improve the enzymatic activity of microorganisms, that is, the microorganisms can produce more urease to decompose urea, and as the amount of urease increases, the concentration of the cementing solution increases, and the calcium carbonate generated by the MICP precipitates. When the concentration of the added cooked glutinous rice slurry was 5%, the unconfined compressive strength of the soil was the largest. In addition, the scanning electron microscope analysis revealed that cooled glutinous rice slurry can be used as a bridge to generate a large amount of ineffective carbonic acid. Calcium atoms are connected together to form effective calcium carbonate, which fills in the pores of the soil as a whole, increasing the compactness of the soil and greatly improving its macroscopic mechanical strength.