Review of Enzyme-Induced Calcite Precipitation as a Ground-Improvement Technique

Heriansyah Putra,Hideaki Yasuhara,Sutoyo Sutoyo,Erizal Erizal,Muhammad Fauzan

doi:10.3390/infrastructures5080066

Heriansyah Putra, Hideaki Yasuhara + Show 3 more

Open Access

https://doi.org/10.3390/infrastructures5080066

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Journal: Infrastructures	Publication Date: Aug 5, 2020
Citations: 34	License type: CC BY 4.0

Affiliation: Bogor Agricultural University

Abstract

Calcite-induced precipitation methods (CIPMs) have recently become potential techniques in geotechnical engineering for improving the shear strength of sandy soil. One of the most promising methods among them is enzyme-induced calcite precipitation (EICP). In this technique, a mixed solution composed of reagents and the urease enzyme, which produces calcite, is utilized as the grouting material. The precipitated calcite in granular soil provides ties among the grains of soil and limits their mobility, thus promoting an improvement in strength and stiffness and also a reduction in the hydraulic conductivity of sandy soil. This paper discusses the potential increase in the strength and stiffness of the soil, the additional materials for grouting, the effect of these materials on the treatment process, and the engineering properties of the soil. The possible sources of the urease enzyme and the applicability of the EICP method to other soil types are also discussed in this paper. The environmental and economic impacts of the application of EICP are also presented. The envisioned plans for application, potential advantages, and limitations of EICP for soil stabilization are discussed. Finally, the primary challenges and opportunities for development in future research are briefly addressed.

Highlights

Numerous feasible methods have recently been developed for various purposes related to ground improvement, such as soil densification, the utilization of synthetic materials [1,2,3], grouting or the deep-mixing method [4,5], and stone columns [4,6]
These results showed that the application of the calcite precipitation method to organic soil is less effective compared to its application to sandy soil
This paper has presented a review of a recently proposed potential technique in geotechnical engineering for improving the engineering properties of sandy soil using enzyme-induced calcite precipitation (EICP)

Summary

Introduction

Numerous feasible methods have recently been developed for various purposes related to ground improvement, such as soil densification, the utilization of synthetic materials [1,2,3], grouting or the deep-mixing method [4,5], and stone columns [4,6]. A variety of materials can be applied for chemical grouting, including cement, lime, or other gel-like materials, depending upon the purpose of the stabilization [6,7,8,9] In this technique, the compound solution is injected into the soil. One of the advancing potential methods uses a type of bio-grout and is called the calcite-induced precipitation method (CIPM) [10,12,13,14,15,16,17,18,19,20,21] It has been studied extensively as a possible ground-improvement method. It can enhance the strength and stiffness of the soil [12,19,21,22] and reduce the permeability [13,14,15,16,23]

Concept of Calcite Precipitation Method

Environmental Impact

10. Effect of Soil Type

Findings

11. Conclusions