Study On Road Performance Of Warm Mixed Phase Change Asphalt Concrete

Because phase change material DTC has the function of temperature regulation,this paper studies the temperature regulation and road mechanical properties of warm mix asphalt concrete by adding different amount of phase change material DTC into the warm mix asphalt concrete from the perspective of actively regulating the pavement temperature to reduce pavement diseases.The main conclusions are as follows:Firstly,infrared spectroscopy shows that no chemical reaction occurs between warm mixing agent and phase change material DTC,which indicates that the preparation scheme of warm mixing phase change asphalt concrete is feasible.Secondly,through the design indoor temperature regulation test and test section test,the results show that DTC can prolong the time when the temperature of asphalt concrete reaches the ambient temperature,and the larger the content,the longer the delay.When the content is 5,the delay is 30 minutes.Therefore,it is recommended that the holding time of specimens for testing mechanical properties should be increased at least 30 minutes on the basis of specifications.Within 24 hours,when the temperature is between-8℃～20℃ and the sunshine is sufficient,the average temperature of DTC-doped pavement is higher than that of non-DTC pavement,which plays a role in regulating the pavement temperature.Finally,the influence laws of different DTC content on pavement performance of Warm-Mix phase change asphalt concrete are studied through tray bending test,rutting test,immersed Marshall test,freeze-thaw splitting test and tray three-point bending fatigue test.The results show that for low temperature performance:With the decrease of test temperature and the increase of DTC content,the maximum bending tensile strength,bending strain and bending stiffness modulus of the tray increase.For high temperature performance:the dynamic stability tends to decrease with the increase of test temperature and DTC content.For water stability:the residual stability decreases gradually with the increase of doping amount,which decreases by 7.8%when the doping amount is 5 compared with that without doping.With the increase of doping amount,the splitting strength ratio firstly increases and then decreases.When the doping amount is 3%,the splitting strength ratio reaches the maximum value of 93.4%.For fatigue properties:considering the effect of freeze-thaw on fatigue properties:the fatigue properties were tested under 5,10 and 15 freeze-thaw cycles,of which 15 freeze-thaw cycles and 5,the fatigue life was reduced by 87.36%compared with that under 0 freeze-thaw cycles,and the damage rate increased by 12.14%during damage development stage.Considering the influence of aging on fatigue performance:the fatigue performance is tested under the effects of non-aging,short-term aging and long-term aging respectively.Among them,long-term aging and 5‰DTC have the greatest impact on fatigue performance.Compared with non-aging and 0‰DTC,the fatigue life decreases by 75.56%and the damage rate increases by 5.43%during the damage development stage.In conclusion,although increasing the amount of DTC will improve the temperature-regulating performance,it will cause high temperature,low temperature,water stability and fatigue performance degradation.Therefore,considering the mechanical properties and temperature-regulating properties of road,it is recommended that the DTC content be 2‰—3‰.