Blast oxygen furnace slag as chemical soil stabilizer for use in roads.

Abstract

Stabilization of poor soils is a technique that can improve engineering properties for road building. Chemical stabilizers such as cement and lime are commonly employed. However, environmental issues and costs involving the production of these materials are making their utilization questionable. Brazil has the fourth largest road network in the world, but only 12% of these roads are paved, which indicates a great need for transport infrastructure at low cost and with good technical and environmental performance. This work proposes the use of basic oxygen furnace steel slag (BOFS) as a chemical soil stabilizer. Sixteen different mixtures of lime, cement, and processed BOFS were tested and compared. The parameters evaluated were unconfined compressive strength, diametrical tensile strength, California bearing ratio, expansibility, and environmental contamination. Results indicate that soils stabilized with BOFS have the same environmental classification as soils stabilized with cement and lime. The BOFS fines successfully stabilized the studied soil, leading to an increase in CBR values of up to 230% along with a decrease in expansibility. The best mechanical performance was observed in the mixture with 15% BOFS and 5% cement by weight, which indicates high performance with high content of BOFS and low cement consumption.