The Role of Nanotechnology in Subgrade and Pavement Engineering: A Review.

Nanotechnology is an extension of sciences and technologies that deal with particles less than 100 nm. This paper reviews previous studies on how nanomaterials work and what their advantages are in subgrade and pavement engineering. In subgrade engineering, the nanomaterials particles can not only improve the physicochemical and mechanical properties of subgrade soils by filling the voids between soil particles but also promote hydration reaction between cement and ion exchange between soil particles. In pavement engineering, the water stability, rutting resistance, fatigue resistance and optical properties of flexible pavements are enhanced by adding nanomaterials into the asphalt mixture. Nanosilica enhances the interface between cement pastes and aggregates and promotes the pozzolanic reaction of concrete, thus, mechanical properties of concrete pavements are improved. Compared with traditional materials, nanomaterials play a promising role in subgrade and pavement engineering, benefitting from their environmental friendliness, lower environmental disturbance, better price/performance ratio and higher durability.