MICROSTRUCTURE AND PROPERTIES OF HYDRATION PRODUCTS OF SLAG-FLY ASH MIXED CEMENTITIOUS MATERIALS

The hydration products,microstructure and strength of slag-fly ash mixed cementitious materials were measured and ana-lyzed by X-ray diffraction and scanning electron microscopy.The composition and microstructure of the hydration products were determined,and the hydration and strength characteristics of slag-fly ash mixed cementitious materials were studied.The results in-dicate that under the action of an excitation agent,surface hydrolysis of slag takes place on the glass body first and the hydration reac-tion occurs.Then the pozzolanic reaction of fly ash takes place.The main compositions of hydration products for slag-fly ash mixed cementitious materials consist of gelating hydrated calcium silicate.The net-shaped microstructure in the cementitious stone is similar to hardened oil well cement.With the increase of curing time,the strength of hardened cement increases continually in the later of the reaction period.