INFLUENCE OF CURING TEMPERATURE ON CEMENT HYDRATION AND MECHANICAL STRENGTH DEVELOPMENT OF FLY-ASH MORTARS

The influence of fly ash and curing temperature on cement hydration an d compressive strength development of mortars was investigated. Test p arameters included type of fly ash (two different Class F fly ashes we re tested), the level of cement replacement (10, 20 and 30% by mass), and curing temperature (20 degrees C and 40 degrees C). The mortar phy sical and microstructural properties were determined by means of therm al analyses, compressive strength measurements and SEM observations. T est results confirm that fly ash tends to increase significantly the r ate of cement hydration at early age. Data also demonstrate that an el evation of the curing temperature reduces the long-term compressive st rength of the reference mortar mixture. In contrast, an increase of th e curing temperature seems to have no detrimental effect on the long-t erm compressive strength of the fly ash mixtures. (C) 1997 Elsevier Sc ience Ltd.