Study of the Use of Dredged Sand as An Alternative to Beach Sand and Coastal Dunes for Coastal Preservation

The need for construction sand needs to increase due to the increase in population. The use of dunes and coastal sand disfigures shorelines and the consequences are alarming. It is therefore necessary to consider replacing these resources with other more ecological ones. Hence, it is the purpose of this article. In this paper, we study the correct formulation of concrete using dredged sand, respecting the standards, and analyze the impact of this new material on the physical and mechanical characteristics of concrete. This article aims to evaluate the effects of 9 formulations, used as substitutes for ordinary sand, on the physico-chemical and mechanical properties. The experimental results have shown that the dredged sand affects the properties of the concrete, but respecting the standards in force. This mode of incorporation also has an environmental advantage over the substitution of concrete for dredged sand, as it reduces the disfigurement of the coasts. The paper studies dredge sands from two regions namely Azemour and Mehdia. The dredging sand partially or totally replaces the dredging sand. Subsequently, it was necessary to test several formulations with different cement dosages before arriving at the formulations which are exposed in this study. The results in the fresh state (consistency test) and in the hardened state (mechanical resistance) have shown that this substitution is possible, and consequently we can use the dredged sands in concretes and in mortars. It is true that the study shows a reduction in resistance compared to a control concrete, but these reductions still remain in accordance with the Moroccan regulatory specifications.