Fabrication of superhydrophobic soil stabilizers derived from solid wastes applied for road construction: A review

The rapid increase in solid waste is one of the hot environmental issues due to the exponential global population growth and ever increasing urbanization. In order to achieve sustainable development, recycling of solid waste becomes a highly desirable target for humans. Solid wastes including geopolymer, biopolymer and synthetic polymer can be processed to produce nontraditional soil stabilizers that are able to replace the traditional ones in road construction. Although the traditional soil stabilizers can improve the mechanical properties of problematic soils, they cannot ensure an adequate amount of water resistance for the treated soils. High water content in the soil structure leads to soil erosion and a reduction in the quality of road construction. Therefore, this paper systematically reviews the recent literature studies on not only the mechanisms of soil stabilization and the current applications of soil stabilizers derived from solid wastes containing geopolymer, biopolymer, and synthetic polymer, but also the fabrication of superhydrophobic materials applied to soil stabilizers. Furthermore, the nontraditional soil stabilizers derived from solid wastes are expected to be fabricated into superhydrophobic ones via certain physical, chemical, and biological treatments. Finally, this review paper discusses the fabrication of new superhydrophobic soil stabilizers that will be available to be applied as future construction materials.