Influence of Environmental Conditions on Durability Properties of Fly Ash Cement Mortars

It is a well known fact that the use of active additions to clinker provides both economical and ecological benefits. The fly ashes have been proved to be materials with pozzolanic activity that improve concrete service properties. The Spanish cement industry produces cements that have different percentage of substitution of clinker by fly ash. Chloride diffusion coefficients have been measured for mortars prepared with cements with different content in fly ash. Those coefficients were determined in saturated samples. Two factors that can have the most severe effect on the behavior of these materials are the moisture and temperature where samples are cured. Most of the experiments are performed in an optimum laboratory environment, close to 100% relative humidity and controlled temperature. In real structures the environment is very different. These conditions can affect the development of the hydration and pozzolanic reactions. The effect of the temperature on the hydration reactions has already been observed.