Effect of the hydration temperature on mechanical resistance of Portland cement mortar and paste.

The hydration of white cement and tricalcium silicate has been investigated at three temperatures (5, 25 and 45°C). Samples were tested after eight periods of hydration during which samples were immersed in saturated lime solution, using: compressive strength determination, and thermogravimetry. Increasing temperature initially accelerated the hydration but a lower hydration degree was observed in the long term comparatively to lower temperatures. The same kind of effect was observed for the evolution of the compressive strength. Whatever the hydration temperature, it was found that compressive strength is a linear function of the hydration degree of which the characteristic is the same for all the temperatures. However the given hydration degree strength is greater for the lower temperature. An explanation of this phenomenon was proposed. It was postulated that mechanical properties are mostly influenced by the product which is created at early hydration period.