流态多源固废固化黄土固化剂配比优化及强度形成机理  

Optimization of Curing-agent Mix Ratio and Mechanism of Strength of Fluidized Multisource Solid-waste Solidified Loesses

作　　者：肖杰[1,2] 刘静 向家骏 刘朝晖 刘财壮[1] 荣亚鹏 刘志勇 常锦[5] 张红日 何建刚 XIAO Jie;LIU Jing;XIANG Jia-jun;LIU Zhao-hui;LIU Cai-zhuang;RONG Ya-peng;LIU Zhi-yong;CHANG Jin;ZHANG Hong-ri;HE Jian-gang(School of Transportation,Changsha University of Science and Technology,Changsha 410114,Hunan,China;Key Laboratory of Highway Construction&Maintenance Technology in Loess Region,Shanxi Transportation Research Institute,Taiyuan 030006,Shanxi,China;China Highway Engineering Consultants Corporation,Beijing 100089,China;Shanghai Key Laboratory of Rail Infrastructure Durability and System Safety,Tongji University,Shanghai 201804,China;School of Civil Engineering,Changsha University,Changsha 410022,Hunan,China;Guangxi Transportation Science and Technology Group Co.Ltd.,Nanning 530007,Guangxi,China;Hunan Renjian Baogu High-tech Development Co.Ltd.,Changsha 410201,Hunan,China)

机构地区：[1]长沙理工大学交通学院,湖南长沙410114 [2]山西省交通科技研发有限公司,黄土地区公路建设与养护技术交通行业重点实验室,山西太原030006 [3]中国公路工程咨询集团有限公司,北京100089 [4]同济大学上海市轨道交通结构耐久与系统安全重点实验室,上海201804 [5]长沙学院土木工程学院,湖南长沙410022 [6]广西交科集团有限公司,广西南宁530007 [7]湖南人健宝固高新科技发展有限公司,湖南长沙410201

出　　处：《中国公路学报》2025年第3期250-263,共14页China Journal of Highway and Transport

基　　金：黄土地区公路建设与养护技术交通行业重点实验室开放基金项目(KLTLR-Y23-1);湖南省交通科技项目(202108);道路结构与材料交通运输行业重点实验室(交通运输部公路科学研究所)2019年度开放资金项目;湖南省自然科学基金项目(2024JJ7618)。

摘　　要：为研究流态工业固废固化黄土在路基工程中应用的可行性,基于响应面法(RSM),以粒化高炉矿渣粉(GBFS)、循环流化床脱硫粉煤灰(CFBFA)、烟气脱硫石膏(FGD)为影响因素,试件7、28 d无侧限抗压强度(UCS)为响应值建立响应面模型,开展了固化剂中掺10%水泥(OPC)时,各固废材料交互作用对流态固化黄土强度的影响研究;优化了固化剂配合比,并结合XRD、FTIR、TG-DTG和SEM微观试验分析了其强度形成的水化作用机理。结果表明:随GBFS掺量增加,CFBFA掺量减小,7、28 d UCS明显增大,GBFS与CFBFA交互作用对UCS的影响显著;随FGD掺量增加,7 d UCS先增后减,而28 d UCS减小,FGD与GBFS交互作用对UCS的影响从7~28 d由显著变为不显著,而与CFBFA交互作用的影响则相反;基于RSM确定的最佳配比,并考虑强度要求及原材料成本,提出当灰土比为0.15、水固比为0.51,固化剂中掺10%OPC时,GBFS、CFBFA和FGD建议的掺量范围分别为43%~50%、25%~32%和8%~15%;在反应初期,OPC水解产生的OH-与FGD溶解出的Ca^(2+)、SO_(4)^(2-)可激发GBFS与CFBFA表面的火山灰活性,生成钙矾石(AFt)与水化硅(铝)酸钙(C—S—(A)—H)连结黄土颗粒并填充颗粒间孔隙,使试件7 d UCS增大;在反应中后阶段,GBFS、CFBFA持续溶解出Ca^(2+)、[SiO_(4)]^(4-)和[AlO_(4)]^(5-)发生火山灰反应,生成更多C—S—H填充结构孔隙和裂缝,试件28 d UCS进一步增大。实际工程应用中,通过调整固化剂原材料配比或灰土比等制备出的流态固化黄土完全能满足一般台背、涵背回填和一般公路路基对强度的要求。A response surface model based on response surface methodology(RSM)was established to investigate the feasibility of using fluidized industrial-solid-waste solidified loess in roadbed engineering.Granulated blast furnace slag powder(GBFS),circulating fluidized bed desulphurization fly ash(CFBFA),and flue gas desulphurization gypsum(FGD)were used as the influencing factors,and the 7 and 28 d unconfined compressive strengths(UCS)of specimens were used as the response values.This study examined the influence of various solid waste materials on the strength of fluidized solidified loess when 10%ordinary Portland cement(OPC)was incorporated into the curing agent.The mixing ratio of the curing agent was optimized,and the hydration mechanism of the strength formation was analyzed using X-ray diffraction,Fourier-transform infrared spectroscopy,thermogravimetric analysis-derivative thermogravimetry,and scanning electron microscopy.The results show that with an increase in the amount of GBFS and a decrease in the amount of CFBFA,the UCS at 7 and 28 d increases significantly,and the interaction between GBFS and CFBFA significantly influences the UCS.With an increase in the FGD dosage,the 7 d UCS first increases and then decreases,whereas the 28 d UCS decreases.The effect of the interaction between FGD and GBFS on the UCS changes from significant to nonsignificant as the curing age increases from 7 to 28 d,whereas the interaction with CFBFA has the opposite effect.On the basis of the optimal ratio determined using RSM,the strength requirements and raw material costs were considered.At a binder-soil ratio of 0.15 and a water-solid ratio of 0.51,the recommended dosages of GBFS,CFBFA,and FGD are 43%-50%,25%-32%,and 8%-15%,respectively.At the beginning of the reaction,OH-released via OPC hydrolysis and Ca^(2+)and SO_(4)^(2-)dissolved from FGD can stimulate volcanic ash activities on the surfaces of GBFS and CFBFA.This promotes the formation of ettringite(AFt)and calcium silicate(aluminum)acid(C—S—(A)—H),which binds loess p

关 键 词：路基工程 流态固化土 粒化高炉矿渣粉 循环流化床脱硫粉煤灰 烟气脱硫石膏 黄土 

分 类 号：U416.1[交通运输工程—道路与铁道工程]