用高岭土制备混凝土膨胀剂的初步研究

通过对高岭土、石膏和氧化钙组成的净浆试体水化产物的SEM形貌观察,研究其膨胀组分的水化产物的形貌及其生成机理和影响因素.研究表明:早期水化产物以起膨胀作用的钙矾石为主,含少量C-S-H凝胶,两者生长速度快.水化1 d时即生成大量针状钙矾石和C-S-H凝胶;2 d时钙矾石呈棒状、条状或团簇结构,C-S-H凝胶出现少量网络状;3 d后条状、棒状钙矾石变粗、体积增大,C-S-H凝胶小网络之间互相交错形成大网络结构.

The Pilot Study on Preparation of Concrete Expanding Admixture by Kaolin

The hydrates of kaolin, gypsum and lime was studied by SEM observation, and the development of expansion ingredient and rules was also studied. The experiment results showed that the main early-age hydrates are lots of ettringite and little C-S-H Gel, which grew fast. Much ettringite and C-S-H gel can be observed after one day, two days later the structure of ettringite became club-shaped, strip or clusters alike, there are little reticulate structure C-S-H gel, after three days club-shaped, strip or clusters alike became big, the small C-S-H gel intersected each other became more bigger reticulate structure.