Conception d’un béton à base de granulats recyclés

Abstract

This thesis explores the design of innovative concretes incorporating recycled aggregates, a response to the scarcity of natural resources in Algeria and the imperative to valorize construction waste. The project aims to develop a sustainable and economically advantageous alternative for the building and public works (BTP) sector, promoting recycling for the benefit of the environment. Recycled aggregates, although less expensive (15% to 30% cheaper than traditional concrete), present technical challenges that can impact durability. Their characterization revealed average abrasion resistance (31.6% fines generated in the Los Angeles test) and more pronounced degradation in the presence of water. Above all, their high water absorption and high water content significantly impact the dosage and workability of concrete, which is crucial for its final durability. The formulation of concrete must therefore precisely adjust the mixing water and incorporate admixtures to compensate for these properties and ensure good durability. Beyond material design, the thesis examines the application of these concretes in structures, such as analyzing the behavior of flexible pavements under load, with or without geogrid reinforcement, using numerical simulations. This work contributes to a better understanding of the integration of recycled aggregates and the optimization of recycling for the environment, highlighting the need for clear standards and continuous research for widespread and sustainable adoption in construction.