工业固废-水泥固化腐殖土的力学响应和微观机制  

Mechanical response and micro-mechanism of humus soil solidified by industrial solid waste-cement

作　　者：金佳旭[1] 秦志发 刘磊[2,3,4] 万勇[2,3,4] 王静[2,3,4] 左胜浩 JIN Jiaxu;QIN Zhifa;LIU Lei;WAN Yong;WANG Jing;ZUO Shenghao(School of Civil Engineering,Liaoning Technical University,Fuxin 123000,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China;IRSM-CAS/HK Poly.Univ.Joint Laboratory on Solid Waste Science,Wuhan 430071,China;Hubei Province Key Laboratory of Contaminated Sludge and Soil Science and Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China;Yellow River Laboratory,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]辽宁工程技术大学土木工程学院,辽宁阜新123000 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [3]中国科学院武汉岩土力学研究所-香港理工大学固体废弃物科学联合实验室,湖北武汉430071 [4]中国科学院武汉岩土力学研究所污染泥土科学与工程湖北省重点实验室,湖北武汉430071 [5]黄河实验室(郑州大学),河南郑州450001

出　　处：《岩土工程学报》2024年第11期2410-2419,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(U20A20320,51979267);湖北省杰出青年基金项目(2021CFA096);中国科学院青年创新促进会项目(2021327)。

摘　　要：为了推动腐殖土在岩土工程领域的资源化利用,采用工业固废(包括生物质飞灰、电石渣和磷石膏)协同水泥对腐殖土进行固化处理。以中国广东省某陈旧型简易垃圾填埋场开采的腐殖土为研究对象,通过常规三轴试验、干湿和冻融循环试验、扫描电镜(SEM)、X射线衍射(XRD)、傅立叶红外光谱(FTIR)和压汞(MIP)测试探究了工业固废-水泥固化腐殖土的三维力学特性、耐久性能及微观机制。试验结果表明:随着P_(o-b)(即工业固废替代水泥的比率)的增加,试样偏应力与轴向应变的关系逐渐由应变软化向应变硬化过渡。三元工业固废的适当掺入(P_(o-b)为25%~50%)有利于减缓干湿循环作用下工业固废-水泥固化腐殖土试样的劣化速率,而纯水泥固化腐殖土试样表现出相对优异的极限偏应力和抗冻性。微观结构分析表明大量钙矾石晶体和C―(A)―S―H凝胶等产物增强了腐殖土颗粒之间的黏结,同时填充了微观孔隙。研究结果可为垃圾填埋场开采的腐殖土修复及再利用提供理论依据。To advance the resource utilization of humus soil within the realm of geotechnical engineering,the industrial solid waste materials(including biomass fly ash,carbide slag and phosphogypsum)cooperated with cement are used to solidify the humus soil.The humus soil mined from an obsolete simple landfill in Guangdong Province,China is solidified by the industrial solid waste-cement.Then the mechanical properties,durability and the underlying microscopic mechanisms are investigated by using the conventional triaxial tests,wet-dry and freeze-thaw cycling tests,scanning electron microscopy(SEM),X-ray diffraction(XRD),fourier-transform infrared spectroscopy(FTIR)and mercury intrusion porosimetry(MIP)tests.The results show that with the increase of P_(o-b)(i.e.,the replacement ratio of cement by industrial solid waste),the relationship between deviatoric stress and axial strain of the samples gradually transits from strain softening to strain hardening.The appropriate incorporation of the ternary industrial solid waste materials(ranging from 25%to 50%for P_(o-b))is beneficial in slowing down the deterioration rate of the industrial solid waste-cement solidified humus soil samples under the action of wetting-drying cycles.Furthermore,the cement-solidified humus soil samples exhibit excellent ultimate deviatoric stress and frost resistance.The microstructural analyses show that a large number of reaction products such as ettringite crystal and C―(A)―S―H gel enhance the bonding between humus soil particles and also fill in the microscopic pores.The research results provide a theoretical foundation for the restoration and reuse of humus soil mined from landfill sites.

关 键 词：腐殖土 固化/稳定化 生物质飞灰 三轴试验 微观机制 

分 类 号：TU43[建筑科学—岩土工程]