工业废渣–水泥协同固化土抗硫酸盐侵蚀性能  

Performances of industrial residue-cement solidified soils in resisting sulfate erosion

作　　者：王子帅 王东星[1,2,3] WANG Zi-shuai;WANG Dong-xing(School of Civil Engineering,Wuhan University,Wuhan 430072,China;Hubei Key Laboratory of Safety for Geotechnical and Structural Engineering,Wuhan University,Wuhan 430072,China;Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering of the Ministry of Education,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学土木建筑工程学院,湖北武汉430072 [2]武汉大学岩土与结构工程安全湖北省重点实验室,湖北武汉430072 [3]武汉大学水工岩石力学教育部重点实验室,湖北武汉430072

出　　处：《岩土工程学报》2022年第11期2035-2042,共8页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(52079098,51879202)。

摘　　要：利用高炉矿渣、粉煤灰、硅灰、电石渣等工业废渣协同水泥固化方法,通过标准养护试样、清水及硫酸盐溶液浸泡试样的表观形貌、无侧限抗压强度、X射线衍射和扫描电镜等测试,揭示工业废渣-水泥协同固化土的力学性能、微观结构和化学反应机制。结果表明:硫酸镁对工业废渣-水泥协同固化土侵蚀效果大于硫酸钠;较纯水泥土而言,工业废渣的加入能够延缓硫酸盐侵蚀作用;经硫酸镁溶液浸泡后,固化土强度在7 d内有一定增长,之后随龄期增加而持续降低,强度保留系数高低依次为高炉矿渣>硅灰>粉煤灰>电石渣;硫酸钠环境下固化土受SO_(4)^(2−)离子侵蚀作用,硫酸镁环境下受SO_(4)^(2−)侵蚀和Mg^(2+)胶结弱化双重作用,导致固化土孔隙增大,侵蚀产物生成量与工业废渣中CaO含量有关。最后,建立了硫酸盐环境下固化土微观反应机制模型,可为工业废渣-水泥协同固化土抗硫酸盐侵蚀研究提供理论依据。To promote application of the industrial residue in coastal soil solidification,the performances of the industrial residue-cement solidified soils(IRCS)in resisting sulfate erosion are investigated.Based on the combination of the cement and the industrial residues(ground granulated blast-furnace slag,fly ash,silica fume and calcium carbide slag),the mechanical behavior,microstructure and intrinsic chemical reaction of the IRCS after standard curing,water soaking and sulfate solution soaking are identified by the appearance observation,unconfined compressive strength,X-ray diffraction and scanning electron microscope tests.The obtained results show that:(1)The erosion of magnesium sulfate to the IRCS is higher than that of sodium sulfate.(2)Compared with the cement-solidified soils,the addition of the industrial residue can significantly alleviate the sulfate erosion.(3)After magnesium sulfate solution soaking,the strength of the IRCS is improved within 7 days and then descends continuously with increasing curing age.(4)The strength retention coefficient of IRCS follows the sequential order as ground granulated blast-furnace slag>silica fume>fly ash>calcium carbide slag.The IRCS in sodium sulfate environment is mainly affected by erosion of SO_(4)^(2−),while the combined effect of sulfate erosion and weakening cementation occurs in magnesium sulfate environment.It will result in the enlarged intergranular pores,and the reaction products are correlated with the CaO content contained in the industrial residues.Finally,the conceptual model for the microreaction mechanism of solidified soils in sulfate environment is established,which provides a theoretical basis for the researches on sulfate resistance of solidified soil.

关 键 词：工业废渣 水泥土 硫酸盐侵蚀 强度 微观结构 

分 类 号：TU43[建筑科学—岩土工程]