为了探究HCSA膨胀剂和速凝剂在喷射补偿收缩混凝土中的水化作用机理,采用X射线衍射(XRD)、扫描电子显微镜(SEM)等分析测试手段,对膨胀剂—速凝剂—硅酸盐水泥三元胶凝材料的水化反应及水化产物特征进行了研究。结果表明:三元胶凝材料水化初期,速凝剂和膨胀剂两种水化反应都消耗了CaSO4,CaO和H2O,抑制了钙矾石AFt,C-A-H和CaCO3的生长,但有大量Ca(OH)2和C-S-H凝胶生成,起到了促凝作用;随着水化龄期的增长,HCSA膨胀剂促使钙矾石晶体逐渐生长,填充了胶凝材料的微孔洞和裂缝,提高其密实度。
In order to research hydration action mechanism of HCSA swelling agent and accelerating agent in spraying shrinkage-com- pensation concrete, applying X-ray diffraction and scanning electron microscope, hydration reaction and characteristic of hydration product of swelling agent-accelerating agent-gelatinization material of portland cement was researched. Results showed that at hydration initial stage of gelatinization material, accelerating agent and swelling agent dissipated CaS04, Ca0 and H20, restrained growth of Aft, C-A-H and CaC03, but there were large amount of Ca (OH) 2 and C-S-H gelatum occurred, which played coagulation role; with hydration time increasing, HCSA swelling agent made Aft crystal grow increasingly, which stowed micro-hole and cracks in gelati- nization material and improved its density.