Activated mechanism of fly ash in portland cement containing calcium sulphoaluminate

The kinds, shapes and quantities of hydration products and the ion concentration in pore solution were investigated during hydration of fly ash or slag portland cement containing calcium sulphoaluminate by differential scanning calorimetry-thermogravimetry analysis, scanning electron microscope and chemical analysis. The distribution of different polymers of silicon-oxygen tetrahedron and different co-ordinate status of alumina were examined by nuclear magnetic resonance. The results show that the activation of fly ash in portland cement containing calcium sulphoaluminate is higher than that of slag. The hydration heat of fly ash cement is high so that it promotes the dissolution of alumina from the glass phase of fly ash. At high temperature, the depolymerization of fly ash glass network is accelerated with the rise of temperature by hydration heat.