Research database

Soil stabilization by binders (e.g. lime and cement) is a widely applied technique to improve hydro-mechanical properties of excavated soils that, otherwise, must be disposed in landfill, with significant economic and environmental costs (energy consumption and CO2 emission in transport, space-consuming in landfills). In this perspective, soil stabilization by binders certainly is a geotechnical engineering application that aims at the sustainable reuse of soils. However, traditional binders production causes significant CO2 emission and extraction of the raw material for their production is an unsolved environmental issue. Soil stabilization using innovative binders such as industrial by-products can increase the sustainability level achieved with stabilization, taking advantage of the circular economy framework. This PRIN proposal aims to further enhance the sustainable feature of the soil stabilization, focusing on both the binder types and theMinistero dell'Università e della Ricerca MUR - BANDO 2022 material to be reused. The main objectives of the research are: (1) Investigate the feasibility of soil stabilization using by-products from industry (e.g. fly ashes, blast furnace slag, marble slurry) allowing their reuse in geotechnical applications. (2) Study the stabilization process of soils whose management represents an environmental issues to be solved (in Italy and abroad) such as dredged sediments or very soft soils. (3) Analyze the stabilization capability of traditional or innovative binders for contaminated materials (e.g. dredged sediments) and for the application in impervious barriers for pollutants containment (e.g. hydraulic cutoff walls). (4) Evaluate the long-term behavior and durability of the stabilized soils after severe and prolonged environmental and chemical conditions. The research will be developed by experimental activities aiming at the chemo-hydro-mechanical characterization of different geomaterials (clayey soils, dredged sediments, very soft soils), before and after stabilization with different types of binders. In particular, the study of different saturation conditions and effectiveness of chemical binder-soils processes will allow to optimize the mix design procedure also by identifying reliable and easy-to-determine parameters to monitor the reaction progress over time, also evaluating the induced modification from a microstructural point of view. The study will be conducted benefiting from the broad background experience and know-how of the three research units on stabilization of soils by traditional binders, behavior of unsaturated soil, laboratory geophysical characterization and microstructural analysis of geomaterials. Each research unit will contribute with its laboratory equipment and expertise. All results and knowledge gained during the project will be disseminated through drafting of technical guidelines and the promotion of a final workshop open to all the interested stakeholders.