Study of the resistance, porosity, and migration of chloride ions of BAPbased crushing sand

Self-compacting concretes (SCC), are hyper-fluid concretes, placed without vibration and are considered as one of the most important innovations of the last decade in construction. SCCs offer many advantages, due to their exceptional characteristics of flow and filling of formwork. Their compositions require a large quantity of fines in order to limit bleeding and segregation. Hence, the use of crushed sand (SC), rich in limestone fines (CF) in the manufacture of self-placing concretes (SCC), can be considered as an alternative source of fillers. These sands reduce the cost of SCC by reducing the high demand for fillers on the one hand and on the other hand, obtaining SCC with good physical and mechanical properties. The main purpose of this paper is to examine the effect of different percentages (0, 5, 10, 15, and 20%) of (CF) in crushed sand on SCC performance. The evolution of the compressive strength, the porosity accessible to water and the migration coefficient of the chloride ions were evaluated. The Okamura method was used for the formulation of all SCC mixtures. Sand/mortar (S/M), water/cement (W / C) ratios and superplasticizer content were kept constant. The results show that (CF) reduce the compressive strength but contribute to the reduction of porosity and migration of chloride ions