聚羧酸系超塑化剂分子结构对C_3S水化行为的影响  

Impact of Molecular Structure of Polycarboxylate Based Superplasticizer on Hydration Behavior of C_3S

作　　者：刘加平[1,2,3] 俞寅辉[1,2] 冉千平[1,2] 乔敏[1,2] 高楠箫[1,2] 

机构地区：[1]江苏省建筑科学研究院有限公司高性能土木工程材料国家重点实验室,南京210008 [2]江苏博特新材料有限公司,南京210008 [3]重庆大学材料科学与工程学院,重庆400045

出　　处：《土木建筑与环境工程》2013年第2期153-158,共6页Journal of Civil,Architectural & Environment Engineering

基　　金：国家重点基础研究计划(973)项目(2010CB735801);国家自然科学基金(51278232)

摘　　要：采用等温量热仪、热分析、扫描电镜等测试手段,研究了3种聚羧酸系超塑化剂(PCs)对硅酸三钙(C3S)水化行为的影响;采用总有机碳测定了不同分子结构的PCs在C3S颗粒上的吸附动力学。结果表明:PCs的掺入大大增加了C3S的诱导期;减缓了C3S的早期水化,但对水化后期发展有利,其中主链为马来酸酐的PC1对C3S水化3d的减缓作用最强;共聚物大部分残留在孔隙液中,其所含的羧酸根含量与对C3S的减缓作用呈线性关系;对C3S诱导期的增加可能是改变了氢氧化钙的临界饱和度。Isothermal calorimeter,thermal analysis and scanning electron microscope were employed to investigate the impact of 3 polycarboxylate-based superplasticizers（PCs） on the hydration behavior of tricalcium silicate（C3S）.In addition,adsorption isotherm was measured by total organic carbon.The results indicate that PCs extends the induction period of C3S.Initial hydration process of C3S is markedly retarded,whereas acceleration is observed in the period of 28 d.And it is found that PC1,with maleic anhydride for its main chain,has the strongest retardation effect.The majority of the copolymer dispersants is remained in the pore solution.Moreover,linear relationship between the content of COO-and its retardation effect is established.Accordingly it is presumed that the critical supersaturation with respect to portlandite can be expected to have a profound impact because of the addition of PCs.

关 键 词：聚羧酸系超塑化剂 硅酸三钙 水化 机理 

分 类 号：TU528.042.2[建筑科学—建筑技术科学]