Etude des propriétés mécaniques à court terme de béton à base de ciment pouzzolanique de synthèse

Abstract

Sediments stemming from operations of dredgings raise numerous environmental and economic problems bound to their future. In the framework of disposal from negative effect to this waste, it is necessary to manage them by measures of valorization in several domains. The main objective of this study brings in within the framework of valorization of the mud stemming operations dredging of the dam of Fergoug as a substituting in the cement. The work consists in studying the short-term mechanical properties of a concrete with pouzzolanique cement of synthesis, this last one is elaborated from a heat treatment of the mud. The first stage consists in verifying the pouzzolaniques properties of calcined mud. In second stage we characterized materials used in our search (sand, gravel, cement, the water). Our contribution concerned the check and the confirmation of the experiences in resistance and in short-term behavior of concretes made from cement consisted of pozzolana of synthesis with calcined mud of dam. These properties were revealings by essays of compression, tension (tension by flexion and fendage) and of shrinkage (endogenous and of dehydration). Three concrete variants were studied: concrete with cement portland artificial, concrete with pozzolana of synthesis (calcined Mud) and the other one with natural pozzolana of Béni-Saf. The incorporation of the additions in the cement was by a substitution of 20 %. The study showed on one hand that the mud stemming from the dam of calcined Fergoug acquired pouzzolaniques properties and on the other hand, this pouzzolanique activity is not dominant at the eraly age, as well as the resistant mechanics for the concrete with cement artificial portland are better. However from 28 days the studied performances get closer sharply to those of the witnesses with only cement, where from the interest of the replacement of a important fraction of mud treated in the cement. This work comes to confirm previous results relative to the improvement of the mechanical performances of cements pouzzolaniques at long-term.