Microstructure as a critical factor of cement mortars' behaviour: The effect of aggregates' properties.

Abstract

The purpose of this work is to assess the influence of the aggregates' properties on the hygric and mechanical behaviour of Portland cement mortars. This assessment allows the establishment of a close relationship between the mortars' performance and its pore size distribution, which is very sensitive to the aggregates' characteristics: It was found that the grain size distribution is the dominant parameter influencing the pore size distribution of the coarse porosity of Portland cement mortars, while the mineralogy and its potential reactivity characteristics have an important role on the volume of the coarse and gel porosity. The main outcome shows a remarkable increase of mechanical strength in mortars with low volume and diameter pore size in the coarse porosity. Moreover, a high average of connected large capillary diameter pores is, in general, associated with an increase of the water flow.