Application of vinyl acrylic co-polymer on subgrade and sub base pavement stabilization

Abstract

A typical method for improving the tensile strength, durability, and swell-shrink behavior of subgrade soil in the pavement is soil stabilization. Numerous researchers have tried a variety of techniques to stabilize the soil. The use of polymer stabilizers has increased, much like other stabilizers. The vinyl-based co-polymer is used in asphalt admixtures, concrete building, dust management, and soil stabilization for highways. Additionally, considering the challenges of the expensive and shortage of stone aggregate in many regions of the country, using locally accessible brick aggregate (i.e over burnt brick aggregate) for sub-base course can be a viable and more affordable solution. The properties of stabilized soil and soil-aggregate combinations were determined at 7 days after cure using the vinyl acrylic co-polymer (K31-APS). By dry weight of the soil and soil-aggregate combination, the vinyl acrylic co-polymer (K31-APS) was added in the ratio of 1:6 (1 part of K31 and 6 parts of water). A combination of soil and aggregate was used in various ratios: 0%, 25%, 50%, and 75%. Laboratory tests such as the unconfined compressive strength and california bearing ratio tests were carried out. Also, scanning electron microscopy test was performed to study the microstructure of the samples. The results showed that adding vinyl acrylic co-polymer to the soil and soil-aggregate combination had no significant changes on maximum dry density but improved the CBR, UCS, and Mr values of the subgrade and sub-base pavement layers in comparison to the unmodified pavement layers. When compared to the unmodified sample, the strength of the soil increased by 94%, while the strength of the soil-aggregate mixture increased by 179%. In contrast, the strength improvements for mixtures of 25% soil and 75% aggregate and 75% soil and 25% aggregate were 50% and 66%, respectively. The addition of vinyl acrylic co-polymer minimizes the thickness of the pavement layers and the cost savings of treated soil-aggregate mixture were found to be 21.63%, 4.77% and 11.02% as compared to untreated sample. Without adding any cementitious material, vinyl acrylic co-polymer (K31-APS) can improve the pavement property with minimum expenses. Consequently, stabilizing the pavement layers with vinyl acrylic co-polymer (K31-APS) stabilizer may be a practical method for constructing roads in a sustainable manner.