三乙醇胺在水泥-水界面的吸附现象及其促凝作用  

Adsorption phenomenon of triethanolmine on the cement-water interface and accelerating effect

作　　者：赵苏[1] 郭兴华[1] 田静[1] 杨海峰[1] 

机构地区：[1]沈阳建筑大学材料科学与工程学院,辽宁沈阳110168

出　　处：《混凝土》2010年第4期66-70,共5页Concrete

基　　金：辽宁省教育厅基金项目(2009S085)

摘　　要：研究三乙醇胺(TEA)在水泥-水界面的吸附现象及其促凝作用机理。考察了TEA对水泥凝结时间和强度的影响,通过表面张力、吸附量,Zeta电位和电导率的测试并借助差热分析和扫描电镜分析其作用机理。在试验条件下,TEA掺量为2%时,促凝效果最佳,初凝时间为237 s,终凝时间为277 s,28 d抗压强度比达到94.4%。TEA可显著降低水泥浆的表面张力,在水泥-水界面的吸附等温线为双平台型(LS),可使水泥颗粒的Zeta电位增大,提高了水泥水化初期的电导率。TEA促进各水泥矿物的溶解,加速了钙矾石和高CaO/SiO2比的C-S-H凝胶的形成,消耗大量的拌合水,促使水铝石的形成并快速向立方体晶型转变,从而起到很好的速凝效果。The adsorption phenomenon of triethanolmine（TEA）on the cement-water interface and accelerating effect mechanism were studied. The setting time and strength of TEA on the cement were investigated.The action mechanism was analysised by surface tension,adsorption,Zeta potential and conductivity test and by means of DTA and scanning electron microscopy.In the experimental conditions,when the mixing amount of TEA is 2%,the accelerating effect is best,its the initial setting time is 237 s,its finally setting time 277 s,and 28 d compressive strength ratio of cement adding triethanolmine was 94.4%.TEA can significantly reduce surface tension of the slurry,its adsorption isotherm of cement-water inter-face is double platform type（LS）,can increase Zeta potential of cement particles,and inprove the conductivity of cement hydration early.TEA can promote the dissolution of cement minerals,accelerates the formation of ettringite and C-S-H gel with high CaO/SiO2 ratio,consumes large amounts of water,increases the formation of the hexagonal aluminate hydrates and promotes conversion to the cubic aluminate hydrate,thus plays very good effect of acceleration.

关 键 词：三乙醇胺 速凝作用 促凝机理 

分 类 号：TU528.042.7[建筑科学—建筑技术科学]