The Water-Repellent Ability of Road Pavement Material Stabilized with Synthetic and Natural Polymers

Abstract

Polymer-stabilized soil continues to be the widely used treatment technique for the road pavement materials. Based on the previous research, the uses of polymer in soil stabilization generally focused on strength and stiffness improvements. Nevertheless, the performance of pavement material is greatly influenced by the moisture ingress, temperature fluctuation, and climate change. In this research, the waterproof ability of soil stabilized with synthetic rubber and natural rubber was investigated. The natural rubber (NR) is one of the natural polymers, which is readily available in Thailand. The styrene butadiene rubber (SBR) is chosen to represent the synthetic rubber in this research. In addition, the performances of soil modified with styrene acrylic (SA) were also evaluated. The SBR and SA are popularly employed as the concrete superplasticizer; they are commonly used to improve the bond of cement paste and waterproof ability of structural concrete. In this research, the optimum dosages of SA, SBR, and NR were determined during the mix design phase. The strength and capillary rise tests of the stabilized soil were conducted and characterized. The images taken from scanning electron microscope were used to evaluate the micro-structural interaction of polymer-stabilized soils. Test results indicate that the synthetic polymers, SA, and SBR, can be used to enhance the strength performance of soil. However, the waterproof abilities of the synthetic polymer-stabilized soils and the compacted soil without stabilizing agent are similar. The NR-stabilized soil showed the poorest performances among the studied materials in this research. On the other hand, the highest 7-day strength and lowest capillary rise values were observed from the cement-stabilized specimen.