Evaluation of spraying technique for heat-reflective coating on asphalt pavements

Heat-reflective coating (HRC) for pavement can effectively mitigate urban heat island (UHI) and reduce pavement distresses, whose cooling effect, service performance and prospective applications have been widely reported, but construction technology investigation is still unavailable. Following this situation, the spraying technology was evaluated with a typical epoxy resin-based HRC, the Dual-Arrhenius viscosity model for coating curing was established, and the factors affecting the curing time were examined by applying typical correlation analysis. Besides, adhesion and abrasion tests were taken to discuss the effect of spraying conditions on mechanical properties. Results show that the available spraying duration of HRC is exponentially negatively correlated with temperature and duration is insufficient for spraying above 323 K. Raising the diluent content could delay the optimal spraying time with a litter effect on the available spraying duration. Pavement temperature is the main factor affecting the curing time and a 20 K increase could decrease the curing time by up to 34%. Repeated spraying after setting the former layer is the best spraying method for HRC, which can effectively improve adhesion and anti-abrasion.