Performance Evaluation of a Self-Compacting Mortar Altered with Dune Sand

In this paper, a laboratory-performed study relating to the evaluation of a self-compacting mortar (SCM) made initially from crushed quarry aggregates and modified by the addition of fine dune sand (DS) is presented. The aim was to show the modification of the rheological, acoustic, and mechanical properties of the SCM brought about by this very fine aggregate, whose use is deemed to be unsuitable for the production of cementitious materials. Though, its valorization could save the overexploited natural resource that is crushed quarry sand (CS). For this purpose, different mortar mixtures made with DS rates of 0%, 25%, 50%, 75%, and 100% by volume of CS were prepared, and subjected to mini-cone flow, ultrasonic pulse velocity (UPV), and destructive compressive and flexural tensile strength tests. The results showed the improvement of several of the parameters studied after the addition of DS, as well as the possibility of using DS in the design of such kinds of mortars even at very high substitution rates. The study also concludes that DS could serve as a viable alternative to CS, in the sense that it could allow to manage in a more sustainable way the otherwise depleting and overexploited supply of quarry sand.