Work

Experimental investigation on the construction waste recycled sand reinforced by soybean urease-induced calcium carbonate precipitation

Year: 2025

Type: article

Abstract: Recycled sand from construction waste presents a promising substitute for natural sand. However, such sand typically exhibits low strength, high crushing index, and poor grading, which collectively compromise its performance in subgrade applications subjected to cyclic shear stresses caused by wave, seismic, and traffic loads. This study investigates the application of Soybean Urease-Induced Calcium Carbonate Precipitation (SICP) method to enhance the engineering properties of recycled sands. Firstly, several factors influencing the precipitation process are examined, including soybean powder concentration, cementation solution concentration and the ratio between urea and calcium chloride. Subsequently, unconfined compressive tests are conducted on sands reinforced under various conditions. Results indicate that the sample strength increases significantly with higher cementation solution concentration and grouting frequency; however, excessively high concentrations lead to a decline in sample strength, likely due to the reduced calcium carbonate precipitation efficiency under supersaturated conditions. Scanning electron microscopy reveals that the reinforcing effect can be attributed to calcium carbonate crystals formed between particles, which function as binding agents for the recycled sands.

Source: Frontiers in Earth Science

DOI: 10.3389/feart.2025.1687298

Authors: Junyi Huang, Dazhi Wu, Zhe Wang, Nan Lu, Shu Liu, Pan Zhou

Institutions: Zhejiang Sci-Tech University, Lishui University, University of Nottingham Ningbo China

Language: English

Topic: Microbial Applications in Construction Materials

Subfield: Environmental Engineering

Field: Environmental Science

Domain: Physical Sciences

SDGs: Responsible consumption and production, Industry, innovation and infrastructure

Open Access status: gold

Estimated APC paid: $3,801