ABSTRACT
Abstract From the literature, the influence of aggregates on the freeze-thaw resistance of concrete is not well established. In the present study, the influence of sand on the durability of mortars subjected to a thermo-mechanical loading is investigated. The following parameters are studied : the nature of sand (siliceous, calcareous, silicocalcareous), its origin (from river or quarry), and its particle size distribution. The mortars are prepared with a cement: sand ratio of 3.375, at the same workability. The prismatic samples (40 x 40 x 160 mm3) are subjected both to three-point flexure and freeze-thaw cycles. The rate of loading is 20 % of the 28-day tensile strength. A coefficient of damage is defined and allows the rating of sand characteristics. The decreasing rating is as follows : the particle size distribution, the origin (sand river behaves better), and finally the nature of the sand (siliceous sand is less efficient). The microstructural investigation of the mortars allows the interpretation of the observed phenomenons.
