镁矿渣水泥基材料的浆—骨界面作用机制研究  

Study on the Mechanism of Cement-bone Interface of Magnesium Slag Cement-based Materials

作　　者：胡瑛莉 胡景宣 HU Yingli;HU Jingxuan(College of Architectural Engineering,Guangxi Polytechnic Institute,Nanning 530000,China;College of Ecological and Environmental Protection,Guangxi Eco-engineering Vocational&Technical College,Liuzhou 545004,China)

机构地区：[1]广西工业职业技术学院建筑工程学院,广西南宁530000 [2]广西生态工程职业技术学院生态环境保护学院,广西柳州545004

出　　处：《金属矿山》2023年第12期240-244,共5页Metal Mine

基　　金：广西壮族自治区教育厅广西高校中青年教师科研基础能力提升项目(编号:2021KY1272)。

摘　　要：镁矿渣水泥基材料的浆—骨界面是最薄弱的结构,是影响宏观力学性能的一个重要因素。通过揭示界面结构作用机制有助于深入了解镁矿渣水泥基材料的微观特性。制备了养护龄期分别为3、7、14、28 d的镁矿渣水泥浆体以及纯水泥浆体,通过开展电子扫描显微镜(SEM)和X射线衍射试验(XRD)分析了养护龄期对浆—骨界面结构的影响,并对比分析了有无掺料的水泥浆体的化学成分变化。研究表明:由SEM图像显示的不同龄期的浆—骨界面结构形貌可知,随着养护龄期增加,骨料和浆体不断混合形成浓稠状,骨料和浆—骨界面的孔隙被水化产物填充,整体更加密实。从物理角度出发,浆体和骨料能够胶结成团的原因为:①由于骨料表面粗糙多孔的特点产生的咬合作用增大了浆—骨界面的摩擦力和黏聚力;②浆—骨界面发生的“水气交换”反应减小了孔隙间距尺寸。从化学角度分析,对镁矿渣浆体和纯水泥浆体进行碱化处理,根据水化沉淀物的XRD衍射结果,发现两者的硅酸二钙(C_(2)S)和硅酸三钙(C_(3)S)峰值差别不大,Ca(OH)_(2)峰值有所下降,这是因为镁矿渣发生火山灰反应消耗了大量的Ca(OH)_(2)。The paste-bone interface of Mg-slag cement-based materials is the weakest structure and is an important factor affecting the macroscopic mechanical properties.By revealing the mechanism of interfacial structure action,it helps to gain insight into the microscopic properties of Mg slag cement-based materials.In this study,magnesia-slag cement slurries and pure cement slurries with curing ages of 3,7,14 and 28 days were prepared,and the effects of curing ages on the structure of the slurry-bone interface and the changes in chemical composition of the cement slurries with and without admixtures were analyzed by conducting scanning electron microscopy(SEM)and X-ray diffraction(XRD)tests.It is shown that the structural morphology of the slurry-bone interface at different ages is shown by SEM images.The images show that with the increase of the curing age,the aggregate and the slurry are continuously mixed to form a dense consistency,and the pores of the aggregate and the slurry-bone interface are filled with hydration products,making the whole denser.From the physical point of view,the slurry and aggregate can be agglomerated for the following reasons:①Because of the rough and porous characteristics of the aggregate surface,the aggregate surface bite increased the friction and cohesion of the pulp-bone interface;②The pulp-bone interface occurs in the"water and gas exchange"reaction to reduce the pore spacing size.From the chemical point of view,the alkali treatment of magnesium slag slurry and pure cement slurry,according to the XRD diffraction results of the hydrated precipitates,it is found that the peak of dicalcium silicate(C_(2)S)and tricalcium silicate(C_(3)S)are not much different between the two,and the peak of Ca(OH)_(2)is decreased,which is because the magnesium slag volcanic ash reaction in the consumption of a large amount of Ca(OH)_(2).

关 键 词：镁矿渣水泥基材料 浆—骨界面 作用机制 物化反应 

分 类 号：TD98[矿业工程—选矿]