Amélioration des performances mécaniques de matériaux de fondations routières par calcification chimique

Common pavement construction and rehabilitation techniques are based on improving the geotechnical state of road materials through compaction or addition of a chemical binder. Despite their high technical efficiency, these mechanical and chemical stabilization operations remain costly and can sometimes impact the environment. To overcome these constraints, the search for alternative solutions that can be fully integrated into the context of sustainable development is booming. Among these solutions, the stabilization by chemical calcification has very recently appeared with the principle of strengthening the soil in place by means of chemically produced precipitates. Chemical calcification involves the introduction into the soil matrix of reagents capable of generating an indispensable reaction to calcium carbonate precipitation. Located at grain contact points, these precipitates form cement bridges that bind soil particles together to improve their mechanical characteristics. In this study, four potential chemical reactions are involved in the proposed precipitation mechanism. These reactions differ in the nature of the chemicals used as sources of calcium and carbonates.