复合胶凝材料水化过程的ESEM观察

ESEM investigation on the hydration process of complex binder

利用环境扫描电镜(ESEM)和X射线衍射分析(XRD)研究了由硅酸盐水泥、粉煤灰和膨胀剂组成的复合胶凝材料的水化产物形貌和硬化浆体结构。复合胶凝材料水化初期有过渡产物钾石膏片状晶体生成,CSH凝胶为约1μm长的晶须,而钙矾石则以六方片状晶核形式存在。在粉煤灰颗粒表面有通过溶解-结晶机制生成的水化产物。在水化后期,CSH成为无特征形貌的致密浆体,其中分布有充分发育的棒状钙矾石晶体。粉煤灰颗粒由表面生成的水化产物与周围的浆体紧密结合成为一个整体。

The morphology of hydration products and the microstructure of hardened paste of complex binder composed of Portland cement,fly ash and expansive agent were investigated with environmental scanning electron microscopy(ESEM)and XRD.There were temporary plate-form syngenite,fibriform CSH and hexagonal plate-form ettringite nuclei forming in early hydrating period.Some hydrate deposited on fly ash particles through solving-depositing process.In later age CSH formed dense paste in which fully grown ettringite disperses.