Recycled aggregate concretes - A state-of-the-art from the microstructure to the structural performance

In the context of a circular economy, the recycling becomes more than more important. In the construction industry, the wastes from the destructions of old structures are significant. The recycling of the old concretes can contribute to reduce the extraction of the new natural resources (gravel, sand) and to reduce the waste deposit areas. Numerous studies have already been performed to investigate different aspects of recycled aggregate concretes (RAC). Several publications have also done the detailed reviews on certain topics of RAC (such as mechanical properties, mix proportioning); however, still few articles have done the global synthesis on different aspects of RAC. This paper presents a rapid state-of-the-art of numerous topics related to RAC: from the recycling techniques of old-concrete-aggregates, the mix proportioning, the mechanical properties, the durability, the structural behavior and the fire resistance. The number of existing studies synthesized is relatively important (about 170 publications). The aim of the present paper is to provide a rapid overview about existing scientific investigations on RAC, which can offer a good guidance to researchers and engineers who are entering to this area. (C) 2020 Elsevier Ltd. All rights reserved.