Space-Time Evolution of Temperature of Asphalt Mixture during Transportation

<div class="section abstract"><div class="htmlview paragraph">Temperature segregation significantly affects the compaction of asphalt mixtures and the durability of the asphalt pavement layer. Uneven cooling of the mixture during transportation is a key factor contributing to temperature segregation. This study uses finite element simulations to analyze the temporal and spatial temperature evolution during the transportation of asphalt mixtures. A temperature segregation evaluation index (TSI<i>v</i>) is proposed to assess the significance of various factors affecting segregation. Support vector regression (SVR), random forest regression (RFR), and extreme gradient boosting (XGBoost) models are employed to predict temperature changes during transportation and optimize the predictive models. The results indicate that the proportion of areas with a temperature difference of less than 10°C is consistently the highest, followed by areas with a temperature difference greater than 25°C, and then those with temperature differences in the ranges of 10-16°C and 16-25°C. Higher discharge temperatures, higher convective heat transfer coefficients, and lower air temperatures are associated with greater temperature segregation. In the early stages of transportation, the discharge temperature has a slightly greater effect than air temperature and convective heat transfer, whereas in the later stages, convective heat transfer plays the most significant role. Both the SVR and RFR models can effectively predict the distribution of various temperature ranges during asphalt mixture transportation.</div></div>