Preparation of a Green Sustained-Release Microcapsule-Type Anti-Icing Agent for Asphalt Pavement and Its Application Demonstration Project

Salt-storage additives (SSAs) were added to the asphalt mixtures during the construction stage, and the formed anti-icing asphalt pavement (AIAP) played an active and smart role in continuous snow melting, which could avoid traffic accidents and provide positive support for winter road maintenance in cold areas. In this study, a novel and economical green sustained-release microcapsule salt-storage anti-icing agent was prepared by using solid waste porous sustained-release skeleton loading organic acetate salt as the core material and styrene-acrylic-acrylate copolymer P(AA-MA-BA-St) as the wall material, which have less corrosiveness and extended the release time. By comparing the physical properties of different solid waste porous carriers and corrosion inhibitors, the blast furnace slag and NaHCO3 were selected as the sustained-release skeleton and corrosion inhibitors. The optimal conditions of the synthesis of vesicle wall materials were investigated: 3.8 wt % acrylic acid polymerized at 110 °C with 3 wt % AIBN and for 3.5 h, and the relative ice-snow melting capacity of the prepared sustained-release microcapsule-type anti-icing agent (SMAA) product was 90.8%. The best proportion of the SMAA used to replace a part of the equal mass of mineral powder in the SMA-13 asphalt mixtures was 5.5 wt %, and it could satisfy the requirements of road performance. Moreover, we applied the SMAA product to the 5 cm thick surface layer of SMA-13 of the section K64 + 992 ∼ K65 + 193.641 over the main line ramp at the Sizhuang Toll Station of Beijing-Xiong'an highways to construct AIAP. Compared with adjacent sections of the road without SMAA in winter snowfall, the pilot test section has a very good melting effect. This study contributes to the development of long-acting environment-friendly materials for SSAs to reduce the cost of winter road maintenance, and the obtained product has very promising prospects for practical applications.