Effect of styrene–butadiene copolymer latex on properties and durability of road base stabilized with Portland cement additive

This study investigated the effects of the type and amount of Portland cement and carboxylated styrene–butadiene emulsion (Tylac® 4190) on the short-term performance of a road base layer via a laboratory evaluation of stabilized soil-aggregate mixtures. Cylindrical specimens stabilized with Portland cement (0–6%), Tylac® 4190 (5–10%), and a mixture of both these additives were molded, cured for 7, 28, and 60 days, and then subjected to different stress sequences to study the unconfined compressive strength, indirect tensile strength, and indirect tensile resilient modulus. The long-term performance (durability) of stabilized soil-aggregate specimens was investigated by conducting wetting and drying (WD) cycling tests on 7-day-cured soil-aggregate specimens stabilized with cement and Tylac® 4190. The results revealed that the additives improved the strength of the specimens, which has been found to be an important quality indicator of road base mechanical properties. Results of tests conducted to assess the specimens’ resistance to WD cycling showed that the addition of a 4% Portland cement–8% Tylac® 4190 mixture resulted in reductions of 86.99% in both water absorption and permeability, volume changes of 88.55%, and weight changes of 92.84% relative to a sample with only 4% cement after 12 WD cycles. This paper also presents the findings of a correlation study conducted for determining the influences of affective variables using nonlinear regression analysis to establish significant prediction models for strength based on mixture parameters.