Effects of Curing Temperature on Strength of Lime-Activated Slag Cement

This paper outlines the effects of curing conditions on the strength and hydration products of lime-activated slag cement. The slag cement was prepared by activating the ground granulated blast furnace slag with lime and plaster of Paris. The curing of mortar specimens was done at temperatures of 27°, 45°, 60°, 75 °C and the compressive strength of specimens were determined after curing periods of 3, 7, 28, 56 and 90 days. The curing temperature is found to influence both the early and later age strengths. For the present test conditions the highest 90-day compressive strength was found to be 47.63 MPa for the specimen cured at temperature of 60 °C. Further, the developed strength in mortar specimens were correlated with the hydration products and microstructure using X-ray diffraction and scanning electron microscope results. Generalized reduced gradient technique is adopted to find the optimum curing temperature for the given raw material composition and this is found to vary marginally on curing period.