Assessing the effectiveness of microbial-induced calcite precipitation (MICP) on sand-silt mixtures with varying silt content, cementation solution and treatment cycles

Abstract

This study evaluated the effectiveness of microbial-induced calcite precipitation (MICP), a sustainable and eco-friendly ground improvement technique, on silty sand with varying silt content. Biotreatment was conducted using Sporosarcina pasteurii and a 0.5 M cementation solution over 7 and 14 days, with 24-hour cycles and pore volumes (PV) of 0.75 and 1. Unconfined compressive strength (UCS) and split tensile strength (STS) tests were performed to assess mechanical properties, while calcite content and microcharacterization were used to evaluate biocementation. Samples with 20% silt exhibited higher strength and CaCO3 content than those with 40% silt. As silt content increased, UCS and STS decreased significantly. Longer treatment durations and higher cementation volumes improved strength and CaCO3 content. A 14-day treatment increased UCS and STS by 35.29% and 56.94%, respectively, while increasing PV from 0.75 to 1 enhanced them by 23.67% and 26.45%. This study highlights the potential of MICP in stabilizing silty sand. © 2025 Informa UK Limited, trading as Taylor & Francis Group.