Breakthrough in Building Materials: Microbially Induced Carbonate Precipitation

Researchers from Taiyuan University of Technology have discovered a method to modify high-sulfur coal gangue using microbially induced carbonate precipitation (MICP), resulting in improved physical and mechanical properties. By using industrial solid wastes as binders and MICP-modified high-sulfur coal gangue as aggregates, the team was able to develop solid precast blocks that exhibited increased durability and reduced reinforcement corrosion risk. The study's findings have significant implications for the building and construction industry, offering a potential solution for the efficient use of waste materials.

Key Takeaways:

• High-sulfur coal gangue, commonly used in concrete production, has high-water absorption, low strength, and is vulnerable to volume expansion, reducing durability and increasing reinforcement corrosion risk.
• MICP-modified high-sulfur coal gangue exhibits improved apparent density, water absorption, crushing index, and total sulfur content, making it a viable alternative for building materials.
• The concentrations of bacterial solution, urea, and Ca2+ played a crucial role in optimizing the properties of MICP-modified high-sulfur coal gangue.
• Solid precast blocks incorporating MICP-modified high-sulfur coal gangue as aggregates demonstrated improved flexural and compressive strengths, attributed to lower water absorption and crushing index, and densified matrix by biogenic CaCO3 production.
• The use of MICP-modified high-sulfur coal gangue in building materials could lead to significant reductions in waste disposal costs and environmental impacts.
• The study's findings offer a promising solution for the efficient use of waste materials in the building and construction industry.

Statistics:

• Apparent density of MICP-modified high-sulfur coal gangue increased by an average of 9.05%.
• Corresponding water absorption, crushing index, and total sulfur content decreased by 40.07%, 23.88%, and 46.69%, respectively.
• The 28-day flexural and compressive strengths of MICP-modified high-sulfur coal gangue blocks were 4.8 MPa and 42.1 MPa, respectively.

Sources:

• Application of Microbially Induced Carbonate Precipitation In Modifying the High-sulfur Coal Gangue and Preparing the Solid Waste-based Precast Block. Construction and Building Materials, 2025;495.
• [Study authors: Zhu Li, Guanhua Jia, Jiangbo Wu, Chunyu Yu, Wei Liu, and Jin Liang]
• [Source publication: Construction and Building Materials - www.journals.elsevier.com/construction-and-building-materials/]
• [Source publisher: Elsevier Sci Ltd, 125 London Wall, London, England]