钡盐对α-高强石膏凝结时间的影响及作用机理  

Effect of barium salt on setting time of α high-strength gypsum and mechanism

作　　者：王楚妍 高建明[1] 唐永波[1] 

机构地区：[1]东南大学材料科学与工程学院,江苏南京211189

出　　处：《新型建筑材料》2015年第9期27-30,共4页New Building Materials

摘　　要：针对石膏凝结硬化快不利于施工的特点,研究2种钡盐Ba CO3和Ba2Si O4作为缓凝剂在不同掺量时对α-高强石膏凝结时间、水化率、抗折、抗压强度和微观形貌等性能的影响。试验结果表明,钡盐对α-高强石膏有很好的缓凝作用,而且随掺量增加缓凝效果显著,此外相同掺量下的Ba2Si O4缓凝效果和强度损失都优于Ba CO3。研究提出了钡盐作为石膏缓凝剂的作用机理在于Ba2+与SO42-反应生成不溶于水的硫酸钡,其包裹在石膏颗粒表面,从而有效抑制了石膏水化反应进程。Gypsum has a very short setting time and this characteristic is not conducive to the construction. The effect of two kinds of barium salt, BaCO3 and Ba2SiO4, on the performance of gypsum such as setting time,hydration rate,compressive strength, flexural strength and micro-morphology is determined. The results show that barium salt is highly effective in retarding and the re- tarding effect is enhanced with the increase of dosage. In the same amount,setting time and strength loss for gypsum containing Ba2SiO4 are better than that of BaCO3. Lots of retarders are produced to delay the hydration induction period. The study put for- ward that Ba^2＋ and SO4^2- in gypsum can generate water-insoluble barium sulfate which could wrap on the surface of gypsum parti- cles to inhibit the reaction process of hydration.

关 键 词：α-高强石膏 钡盐 缓凝剂 水化率 凝结时间 

分 类 号：TU526[建筑科学—建筑技术科学] TQ177.377[化学工程—硅酸盐工业]