OPTIMISATION DE LA FORMULATION D’UN ÉCO-BÉTON À BASE DE SÉDIMENTS DE DRAGAGE ET ÉTUDE DE SA RÉSISTANCE AUX ATTAQUES CHIMIQUES

Abstract

After an identification of the physical and mechanical characteristics, the mineralogical composition, the environmental impact of the dam dredging sediments and the potential use of these materials in civil engineering are evaluated. To improve, in particular, their behavior in the fresh and hardened state as well as their durability. Processed sediments with pozzolanic properties can be used as cement additives or substitutes, which make concrete technology a preferred route for their upgrading. This research work aims to contribute to the valorization of the vases resulting from these dredging operations at dams, in this case Chorfa (Western Algeria) as a mineral addition in the composition of ordinary economic concretes. It is a question of comparing the influence of the addition of the mud on the physico-mechanical characteristics and on the durability of these concretes in the short, medium and long term. In total, four formulations were studied covering three different CPA CEMI 42.5 (10%, 20% and 30%) after calcination at 750 ° C to make them active and a 0% control concrete Vase: an ordinary vibrated concrete with 10% vase (MOPCC 10%), an ordinary vibrated concrete with 20% vase (MOPCC 20%), an ordinary vibrated concrete with 30% vase (MOPCC 30%) and finally a concrete CC 00%) without additions for the need for comparison. The results of measurement of the compressive strengths obtained are very close with a slight superiority for concrete (MOPCC 10%) and (MOPCC 20%) in the long term. The results of the capillary absorption tests, the porosity accessible to water, the diffusion coefficient of chloride ions, the water permeability, the sulphat attack (MgSO4), Acid attack (H2SO4), seawater and natural carbonation, show that concretes containing calcinated sludge have an appreciably better influence than concrete without sludge on the physico-mechanical properties and the durability of the concretes in which it is incorporated.