Desiccation cracking remediation through enzyme induced calcite precipitation in fine-grained soils under wetting drying cycles  

作　　者：Kaniz Roksana Shaini Aluthgun Hewage Melissa Montalbo Lomboy Chaosheng Tang Wei Xue Cheng Zhu 

机构地区：[1]Department of Civil and Environmental Engineering,Rowan University,Glassboro,NJ 08028,USA [2]Experiential Engineering Education(ExEEd),Rowan University,Glassboro,NJ 08028,USA [3]School of Earth Sciences and Engineering,Nanjing University,Nanjing 210046,China [4]Department of Mechanical Engineering,Rowan University,Glassboro,NJ 08028,USA

出　　处：《Biogeotechnics》2023年第4期13-27,共15页生物岩土技术（英文）

基　　金：supported by a subaward from Rutgers University,Center for Advanced Infrastructure&Transportation,under Grant no.69A3551847102 from the U.S.Department of Transportation,Office of the Assistant Secretary for Research and Technology(OST-R).

摘　　要：The effects of desiccation cracking in clay soils on geotechnical constructions are substantial.This study investigates the viability of utilizing Enzyme-induced calcite precipitation(EICP),a bio inspired approach,as a potential solution for addressing desiccation cracking in fine-grain soils.For the EICP technique,crude soybean extract is employed for the purpose of urea hydrolysis.Multiple fluid samples,including a control sample,a cementation solution containing 1 M urea,0.675 M CaCl_(2),and 4 g/L milk,along with various concentrations of enzyme solutions(3-80 g/L),were tested for the study.To evaluate the surface cracking patterns,the method involved constant monitoring and photo recording using a high-resolution camera aided by image processing software.The results showed that fine-grain soils improved from increased calcite precipitation and decreased desiccation cracking intensity when the EICP method was used.Cementation and enzyme solution with low concentrations(3 g/L and 10 g/L)had similar effects on crack remediation,suggesting a modest influence.In contrast to the sample treated with water,the crack network remained unaltered in this case.CaCO3 precipitation within the void area kept the crack network in place even as the void thickness decreased at increasing enzyme concentrations(30 g/L,50 g/L,and 80 g/L).Wetting and drying cycles were found to decrease the crack ratio,crack width,and crack length in the EICP-treated sample,particularly under higher concentrations of urease enzyme.Lower enzyme concentrations of 3 g/L and 10 g/L have minimal impact on crack remediation but effectively inhibit new crack formation.Furthermore,higher enzyme concentrations result in calcium carbonate precipitates,forming a soil crust and increasing surface roughness.The study aims to enhance understanding of the EICP methodology and to provide novel perspectives on potential uses for soil enhancement.

关 键 词：Desiccation crack Wetting-drying cycle Bio cementation Plant-based EICP 

分 类 号：TG1[金属学及工艺—金属学]