A novel approach to induce cementation of loose soils

In order to create cementation of loose soils, cement or lime is usually used. In this paper, we used bacteria to produce cementation of loose soils. We introduced the bacteria, Bacillus, and CaCl ₂ into loose sand and soft silt, CaCO ₃ in the voids of soil particles will be formed, resulting in cementation of soil particles. In this study, loose sand and soft silt typically encountered in Korea were bio-treated with 3 types of bacteria concentration. The cementation (or calcite precipitation) in the soil particles induced by the high concentration bacteria treatment (which has never been attempted before) was investigated at 7 days after curing. Based on the results of Scanning Electron Microscope (SEM) tests, EDX analyses, 3D mapping analyses, high concentration bacteria treatment for loose sand was observed to produce noticeable amount of CaCO ₃, implying a significant cementation of soil particles. In addition, a significant increase in the compressive strength of loose sand has been identified feasible by bio-treatment without any cementing agent.