Performance evaluation of temperature-regulating asphalt mixture with thermochromic materials and low freezing point materials

Abstract

Asphalt pavement absorbs a lot of heat in the summer because of its dark surface, which makes it susceptible to high-temperature. By altering the asphalt pavement’s ability to reflect solar radiation, thermochromic materials can regulate the temperature of the road. However, the thermochromic modified asphalt’s ability to regulate temperature is weak during the winter, when the road surface is covered in snow and ice or when there is no direct sunlight. Materials with low freezing points can lower the pavement’s freezing temperature and produce the snow melting and deicing effects. A type of temperature-regulating road asphalt material can be created by mixing low freezing point material and thermochromic material in a certain ratio with road asphalt. The blue thermochromic materials of 3%, 5% and 7% by weight were applied to the matrix asphalt to prepare thermochromic asphalt binders, respectively. The low freezing point materials replaced 25%, 50% and 75% of the mineral filler volume.The pavement performance, deicing performance and cooling performance of the tempering asphalt mixture were evaluated by orthogonal test design. According to the findings, the temperature-regulating asphalt combination performs substantially better at cooling and deicing than the unmodified asphalt mixture. When the replacement rate of low freezing point materials changes from 25 % to 75 %, the bond strength loss of modified asphalt mixture increases from 46 % to 75 %. The pavement surface temperature can be reduced by a maximum of 4–9 °C during the day by using a temperature-regulating asphalt composition. In this study, it is advised to use 5 % thermochromic dosage and 50 % replacement rate of low freezing point materials, taking into account the overall balance of performance enhancement.