Recent applications and developments of Polyurethane materials in pavement engineering

In the past decades, Polyurethane (PU) as an emerging polymer material has been widely used to construct, repair, reinforce, and protect civil engineering infrastructures. Meanwhile, various PU-based materials are increasingly employed in pavement engineering for new construction and maintenance, due to their excellent physical and chemical properties. In this review paper, the synthesis method, chemical structure, and engineering properties of PU materials were first introduced briefly. Secondly, the practical applications of PU materials in pavement engineering at present were summarized, mainly including PU-modified asphalt, PU-bonded mixture, PU sealant, and PU foam injection. Finally, the potential economic benefits and environmental impacts of utilizing PU materials in pavement engineering were further discussed towards sustainability.