Microstructure and properties of activated slag cement

Activation of the slag cement was performed using a composite activator. Experimental results show that the performance of the cement is remarkably improved. The fineness and specific surface area of the cement are increased by 23.7% and 1.4%, and 3 d flexural strength and compressive strength are enhanced by 20.9% and 22.9%, respectively. Microstructure and phase composition of the hydrates were analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicate that Ca(OH)2 in the hydrates decrease obviously. The morphology of the other hydrates appears to be flocculent, with a dense structure. The improvements of the properties is related to the microstructural changes.