Study On The Performance Of Phase-change Temperature-adjusting Asphalt Mixture

Asphalt pavement with its unique evenness, comfort, low-noise and other advantages hasbeen widely used in highway and urban roads. However, the functional performance ofasphalt pavement is still significantly affected by diseases associated with temperature.Domestic and foreign researchers carry out the researches by using modified bitumen, mixingwith anti-rutting agent and so on to reduce adverse effects passively when facing changes inambient temperature. But the effect is limited. This study attempts to mix the phases changematerials to asphalt mixture to active control the working temperature of asphalt mixture inorder to improve the temperature stability of asphalt pavement.This study analyzes the thermo physical properties of phases-change temperature-adjusting additive. The results indicate that it has good heat of fusion and durability. Theeffect of phase-change temperature-adjusting asphalt mixture is analyzed by specific heatcapacity test, indoor and outdoor model test. Its results show that the asphalt mixture couldreduce heating and cooling rates and delay the appeared time of extreme temperature. On thebasis of the results reveals the thermostatic mechanism. The temperature stress andtemperature fatigue life of asphalt pavement is calculated. The calculation results show thatthe temperature stress decreases and the temperature fatigue life increases. The Marshall Testresults show that the optimal asphalt content is not obviously influenced when additives areapplied. The road performance of asphalt mixture is also analyzed. The results indicate thatroad performance can meet the technical requirements in Chinese specification. Along withthe increasing content of additives in asphalt mixture, the high-temperature stability decreasesand the low-temperature anti-cracking stability increases. Phase-change temperature-adjustingadditives are not influenced the effect of optimal asphalt content and aggregate gradation onroad performance. The comprehensive analysis results show the optimal content ofphase-change temperature-adjusting additives is0.3%~0.5%in asphalt mixture.