Imran Md Al, Nakashima Kazunori, Evelpidou Niki, Kawasaki Satoru
Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan.
Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan.
Materials (Basel). 2022 Mar 24;15(7):2389. doi: 10.3390/ma15072389.
Soil improvement via MICP (microbially induced carbonate precipitation) technologies has recently received widespread attention in the geoenvironmental and geotechnical fields. The durability of MICP-treated samples remains a critical concern in this novel method. In this work, fiber (jute)-reinforced MICP-treated samples were investigated to evaluate their durability under exposure to distilled water (DW) and artificial seawater (ASW), so as to advance the understanding of long-term performance mimicking real field conditions, along with improvement of the MICP-treated samples for use in coastal erosion protection. Primarily, the results showed that the addition of fiber (jute) improved the durability of the MICP-treated samples by more than 50%. Results also showed that the wet-dry (WD) cyclic process resulted in adverse effects on the mechanical and physical characteristics of fiber-reinforced MICP-treated samples in both DW and ASW. The breakdown of calcium carbonates and bonding effects in between the sand particles was discovered to be involved in the deterioration of MICP samples caused by WD cycles, and this occurs in two stages. The findings of this study would be extremely beneficial to extend the insight and understanding of improvement and durability responses for significant and effective MICP treatments and/or re-treatments.
通过微生物诱导碳酸盐沉淀（MICP）技术进行土壤改良最近在地质环境和岩土工程领域受到了广泛关注。在这种新方法中，经MICP处理的样品的耐久性仍然是一个关键问题。在这项工作中，对纤维（黄麻）增强的经MICP处理的样品进行了研究，以评估它们在暴露于蒸馏水（DW）和人工海水（ASW）时的耐久性，从而增进对模拟实际现场条件下长期性能的理解，并改进用于海岸侵蚀防护的经MICP处理的样品。主要结果表明，添加纤维（黄麻）使经MICP处理的样品的耐久性提高了50%以上。结果还表明，干湿（WD）循环过程对纤维增强的经MICP处理的样品在DW和ASW中的力学和物理特性产生了不利影响。发现碳酸钙的分解以及砂粒之间的粘结作用与WD循环导致的MICP样品劣化有关，且这一过程分两个阶段发生。本研究的结果对于深入了解和理解有效且显著的MICP处理和/或再处理的改良及耐久性响应将极为有益。
