Microbially induced stabilized rammed earth: Compressive strength-capillary water absorption Co-relationship

Area of Science:

• Construction Materials Science
• Geotechnical Engineering
• Biotechnology

Background:

• Rammed Earth (RE) is a sustainable building material stabilized with cement.
• RE's susceptibility to water absorption through pores reduces its strength and lifespan.
• Current methods lack effective pore-filling solutions for cementitious materials in RE.

Purpose of the Study:

• To investigate the efficacy of Microbially Induced Calcium Carbonate Precipitation (MICP) in improving cement-stabilized RE.
• To assess the impact of MICP on compressive strength and water absorption.
• To establish a relationship between strength and water absorption in MICP-treated RE.

Main Methods:

• Incorporation of MICP during the casting of cement-stabilized Rammed Earth specimens.
• Compressive strength testing of treated and untreated specimens.
• Capillary water absorption tests to evaluate durability.

Main Results:

• MICP treatment resulted in an average 26% increase in compressive strength.
• Significant reduction in capillary water absorption observed in MICP-induced specimens.
• A correlation between enhanced compressive strength and reduced water absorption was established.

Conclusions:

• MICP shows significant potential for enhancing the performance of cement-stabilized Rammed Earth.
• The technique effectively fills pores, inhibiting water absorption and extending material lifespan.
• Further research is warranted for widespread microbial stabilization in RE construction.