生活垃圾焚烧炉渣集料的胶凝特征

为研究垃圾焚烧炉渣集料(BAA)的胶凝特征,以强度试验分析BAA的水硬性和火山灰活性,并采用X射线荧光光谱仪、X射线衍射仪和扫描电子显微镜分析微观作用机理.结果表明,BAA含有水泥熟料矿物和活性SiO_2、Al_2O_3,体现出水硬性和火山灰活性特征.BAA中水泥熟料矿物遇水发生水化反应生成水化硅酸钙(C-S-H)凝胶和Ca(OH)_2,活性SiO_2、Al_2O_3在Ca(OH)_2激发作用下发生火山灰反应生成C-S-H凝胶、水化硅铝酸钙等水化产物;BAA与水泥、水混合后,除上述反应外,活性Al_2O_3在硫酸盐激发下也发生火山灰反应生成钙矾石.BAA在水泥中的火山灰反应有一定延后性.湿法处理、长时间堆放BAA的胶凝活性分别较干法处理、短时间堆放BAA低.

Cementitious Properties of Municipal Solid Waste Incineration Bottom Ash Aggregate

In order to research cementitious properties of municipal solid waste incineration bottom ash aggregate (BAA), hydraulic activity and pozzolanic activity of BAA were analyzed by strength test, and X ray fluorescence (XRF), X ray diffraction (XRD) and scanning electron microscope (SEM) were also used to study the microscopic mechanism. The results show that BAA consists of cement clinker mineral, active SiO2 and Al2O3. BAA has hydraulic activity and pozzolanic activity. Cement clinker minerals in BAA react with water to produce calcium silicate hydrate (C S H) gel and Ca(OH)2. Pozzolanic reaction occurs when active SiO2 and Al2O3 are activated by Ca(OH)2 to form hydration products like C S H gel and calcium silicoaluminate hydrate. When BAA mixes with water and cement, besides the reactions mentioned above, pozzolanic reaction also occurs when active Al2O3 is activated by sulfate to form ettringite. Pozzolanic reaction of BAA in cement delays to some extent. Wet processed BAA shows lower cementitious properties than dry processed BAA, and BAA with longer weathering time also has lower cementitious properties.