Adaptation of alkalophilic bacterial strain, inducing CaCO3 precipitation, to improve the recycled concrete aggregates quality

Microbiologically induced CaCO3 production (MICP) is a process employed in several domains. Biocarbonatation was first study and employ to preserve and repair calcareous ornamental stones. Then, studies have been conducted to use MICP with concrete, with the aim to improve the quality of the material, repair cracks, or produce a self-healing concrete. The aim of this study is to evaluate the interest of using MICP with cement-based road construction. Because recycled concrete aggregate (RCA) are widely used in road construction, this study will focus on the improvement of RCA quality by MICP. So, after the selection of an alkalophilic bacterial strain, there was an analysis and a quantification of its CaCO3 production. Then, X-ray diffraction (XRD) and thermogravimetric analysis (TGA) have been conducted on precipitate formed. After that, selected bacteria have been contacted with RCA to study their influence on RCA's properties. © EDP Sciences, 2017.