EFFECT OF TEMPERATURE ON THE HYDRATION OF THE MAIN CLINKER PHASES IN PORTLAND CEMENTS - PART I, NEAT CEMENTS

The hydration of two Mexican Portland cements has been investigated at five temperatures in the range from 10 to 60 degrees C. Samples were tested after eight periods of hydration during which they were immerse d in water for between 1 day and 360 days, using quantitative X-ray di ffraction, thermogravimetry, compressive strength determination, and s canning electron microscopy. Increased temperature initially accelerat ed the hydration of the four major anhydrous phases present in both ce ments. In the longer term, however, a reduced degree of hydration was observed for the alite and ferrite phases, accompanied by decreased co mpressive strength and increased apparent porosity. (C) 1998 Elsevier Science Ltd.