冻融循环下MICP固化风积砂的性能劣化试验研究  

Experimental study on performance deterioration of MICP-cured aeolian sand under freeze-thaw cycles

作　　者：刘小军[1,2] 朱芮 王东亚 孙跃 LIU Xiaojun;ZHU Rui;WANG Dongya;SUN Yue(School of Civil Engineering,Xi’an University of Architecture and Technology,Xi’an Shaanxi 710055,China;Key Laboratory of Geotechnical and Underground Space Engineering of Shaanxi Province,Xi’an Shaanxi 710055,China)

机构地区：[1]西安建筑科技大学土木工程学院,陕西西安710055 [2]陕西省岩土与地下空间工程重点实验室,陕西西安710055

出　　处：《中国安全生产科学技术》2025年第4期71-78,共8页Journal of Safety Science and Technology

基　　金：陕西省自然科学基础研究计划项目(2020JM-483)。

摘　　要：为了探究微生物诱导碳酸钙沉淀技术(microbial induced calcium carbonate precipitation,MICP)固化风积砂在冻融循环影响下的劣化机理,在微生物加筋联合糖钙固化风积砂的基础上对加固试样进行冻融循环试验,通过分析质量损失、无侧限抗压强度、压汞试验及微观试验,分析冻融循环对微生物固化风积砂的劣化机理。研究结果表明:加固试样在冻融循环过程中,表面剥蚀情况加剧,出现蜂窝、麻面等劣化情况;质量损失率在10次循环后开始收敛;试样强度随着循环次数增加先减小后收敛,到20次时降至最低;试样孔隙随着循环次数增加逐渐增大,整体性能下降;在低次数冻融循环中,主要影响胶结较差的砂颗粒间的碳酸钙晶体,高次数循环后试样表面变光滑,碳酸钙晶体流失,导致颗粒联结减弱,试样强度和整体性能下降。研究结果可为MICP加筋联合糖钙固化风积砂更好地应用到实际工程中提供指导。To investigate the deterioration mechanism of microbial induced calcium carbonate precipitation(MICP)cured aeolian sand under freeze-thaw cycles,the freeze-thaw cycle tests were conducted on the reinforced specimens based on the microbial reinforcement combined with sugar calcium cured aeolian sand.By analyzing the mass loss,unconfined compressive strength,mercury intrusion test and microscopic test,the deterioration mechanism of freeze-thaw cycle on the MICP-cured aeolian sand was analyzed.The results show that during freeze-thaw cycles,the surface erosion of cured specimens intensifies,exhibiting the deterioration features such as honeycombs and pitted surfaces.The mass loss rate begins to converge after 10 cycles.The specimen strength initially decreases with the increasing cycles and then converges,reaching its minimum at 20 cycles.The pore size gradually increases with the increasing cycles,and the overall performance decreases.At the lower number of freeze-thaw cycles,the primary damage occurs in poorly cemented calcium carbonate crystals between sand particles.After the cycles with higher number,the specimen surface becomes smoother with the loss of calcium carbonate crystals,weakening the interparticle bonding and further reducing the specimen strength and overall performance.The research results can provide guidance for the practical application of MICP-reinforced sucrose-calcium cured aeolian sand in engineering projects.

关 键 词：冻融循环 MICP 力学试验 劣化机理 

分 类 号：X947[环境科学与工程—安全科学]