Influence of addition of butadiene copolymer and modified styrene on the mechanical behavior of a sand

Butadiene-styrene copolymer (SBR) is an elastomer composed of 75% butadiene and 25% styrene and is widely used in the automotive industry in tire production. This elastomer can be produced from two polymerization processes: emulsion or solution polymerization. This paper presents the mechanical behavior of a polymer reinforced sand compared to pure sand. Direct shear tests were performed on pure sand specimens and with the addition of modified styrene butadiene-styrene copolymer (XSBR). The polymeric sand specimens had 10% moisture content, 50% relative density, with water-polymer mass ratios of 1:1, 1:2, and 1:4, with no curing time, or with curing times 48, 72, 96, 576, and 720 h. Improvements were verified in the strength parameters of sand specimens with polymer addition, while comparing with pure sand parameters, showing that the improvement of soils with polymers is satisfactory for application in geotechnical works, such as: embankments in soft soils, soils for shallow foundations and for slope stability.