干湿循环作用下聚丙烯纤维对酶诱导碳酸盐沉淀固化砂土的耐久性研究  

Durability study of polypropylene fibers on enzyme-induced carbonate precipitation cured sandy soil under dry-wet cycling

作　　者：张建伟[1,2] 吕子壮 李想 郑俊杰 盛桂琳 李青飞[1] ZHANG Jianwei;LYU Zizhuang;LI Xiang;ZHENG Junjie;SHENG Guilin;LI Qingfei(School of Civil Engineering and Architecture,Henan University,Kaifeng 475004,China;Henan Province Research Center for Intelligent Protection and Restoration of Historical Buildings,Kaifeng 475004,China;Shanghai Huanqiu Contracting&Engineering Corp,Shanghai 200030,China;School of Civil and Architectural Engineering,Wuhan University,Wuhan 430072,China)

机构地区：[1]河南大学建筑工程学院,开封475004 [2]河南省历史建筑智能保护与修复工程研究中心,开封475004 [3]上海寰球工程有限公司,上海200030 [4]武汉大学土木建筑工程学院,武汉430072

出　　处：《复合材料学报》2025年第2期1000-1009,共10页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金项目(42177454);河南省科技研发计划联合基金项目(225200810005);河南省自然科学基金项目(232300420073)。

摘　　要：为了研究砂土在干湿循环作用下的耐久性,进行纤维加筋法改良酶诱导碳酸盐沉淀(EICP)的研究。将废弃口罩粉碎后作为纤维加筋,研究了不同纤维掺量和不同循环次数下砂土的无侧限抗压强度、质量损失率、浸泡吸水率、碳酸钙含量的变化,并结合扫描电子显微镜从微观层面分析聚丙烯纤维联合EICP固化砂土的机制。研究结果表明:随着干湿循环次数的增加,改良砂土的无侧限抗压强度逐渐减小,并且在纤维掺量为0.2wt%时试样强度损失率最小,纤维过少无法形成“桥梁作用”,过多容易出现团聚体;并且纤维加筋能显著提高EICP固化砂土的碳酸钙生成率,还可以起到固定碳酸钙晶体的作用;质量损失率随干湿循环次数先减小后增大,纤维掺量为0.2wt%时最小;聚丙烯纤维加入后,可以生成更多碳酸钙填充空隙,减少干湿循环中水流的侵蚀作用。To study the durability of sand under the action of dry and wet cycling,the fiber reinforcement method to improve enzyme induced carbonate precipitation(EICP)was studied.Utilizing the waste mask as fiber reinforcement after crushing,the unconfined compressive strength,mass loss rate,soaking water absorption rate,and calcium carbonate content of sand under different fibers content and different dry-wet cycles were studied.Additionally,the method of EICP combined with polypropylene fiber solidification of sand soil was integrated with scanning electronic microscopy under the microscope.The results demonstrate that the improved sand soil's unconfined compressive strength gradually decreases as the number of dry-wet cycles increases.At the minimum sample strength loss rate at the fibers content of 0.2wt% set,too few fibers are unable to form the"bridge effect"and too many fibers are too prone to clustering.Additionally,the fibers reinforcement can significantly increase the production of calcium carbonate in EICP-solidified sand soil and can also play a role in fixing calcium carbide crystals.The number of dry-wet cycles causes the quality loss rate to first decline before increasing and the rate is lowest when the fibers content is 0.2wt%.Following the addition of polypropylene fibers,more calcium carbide is generated to fill in gaps and lessen the erosion effect of water flow in the dry-wet circulation.

关 键 词：EICP 聚丙烯纤维 大豆脲酶 干湿循环 微观分析 

分 类 号：TU443[建筑科学—岩土工程] TB332[建筑科学—土工工程]