Sandy Soil Improvement through Microbially Induced Calcite Precipitation (MICP) by Immersion

Area of Science:

• Geotechnical Engineering
• Microbiology
• Materials Science

Background:

• Microbially Induced Calcite Precipitation (MICP) is a promising technique for soil improvement.
• Traditional injection methods for MICP can lead to uneven distribution of cementation agents.
• Improving the uniformity of calcite precipitation is crucial for effective soil stabilization.

Purpose of the Study:

• To develop and evaluate an immersion method for treating soil samples using MICP.
• To compare the uniformity of calcium carbonate (CaCO3) distribution achieved by the immersion method versus traditional methods.
• To investigate the effect of different soil sample holders and fiber reinforcements on MICP treatment.

Main Methods:

• A batch reactor was designed to immerse soil samples in cementation media.
• Various soil sample holders were utilized, including full contact flexible, rigid full contact, and cored brick molds.
• Synthetic and natural fibers were incorporated to reinforce the MICP-treated soil samples.
• The distribution of precipitated CaCO3 within the treated samples was quantitatively assessed.

Main Results:

• The immersion method allowed for free diffusion of cementation media into soil samples.
• Uniform distribution of precipitated CaCO3 was observed throughout the soil samples treated by the immersion method.
• Different mold types and fiber reinforcements were tested, with CaCO3 distribution being the primary focus.

Conclusions:

• The developed immersion method effectively improves the uniformity of microbially induced calcite precipitation in soil samples.
• This technique offers a viable alternative to injection methods for enhanced soil stabilization.
• Uniform CaCO3 distribution achieved through immersion leads to more consistent and reliable soil treatment outcomes.