Study On Warm Mixing Performance Of Polyethylene Waste Plastic Cracking Wax Modified Asphalt

The production temperature of the traditional hot mix asphalt mixture(HMA)is too high,not only consumes a lot of energy,but also emits a lot of exhaust gas and dust during the construction process,polluting the surrounding environment and endangering the health of the construction personnel.Asphalt aging causes the asphalt pavement to crack in advance and shorten its service life.Warm-mixed asphalt mixture(WMA)technology effectively reduces the temperature of asphalt mixture production and rolling process without affecting the road performance of asphalt mixture.It saves energy and reduces emissions.It has good economic and environmental benefits,but at present,the production cost of warm mix is high and the price is expensive,which severely limits the large-scale promotion and application of warm mix technology.Based on this,from the perspective of reducing environmental pollution and plastic resource utilization,this study selected polyethylene-based waste plastics(waste HDPE and LDPE mixed in a 1: 1 ratio)as the cracking raw materials,and the high temperature cracking products at different temperatures WMa-1 and WMa-2 are used as the organic viscosity-reducing and temperature-reducing admixture of 70 # road asphalt.The content of the warm admixture is 2%,4%,6%,8%,and 10% respectively.Plastic cracked wax warm mix asphalt.The main research contents are:(1)The conventional physical properties,viscosity-reducing effect and rheological properties of warm-mixed asphalt were studied,and the appropriate warm-mixing agent and its optimal blending ratio were determined through the changes of various technical indicators;(2)On this basis,the performance of warm-mixed asphalt binder is discussed,and the mechanism of the two waste plastic cracking waxes is briefly analyzed;(3)The mix-ratio design of the warmmixed asphalt mixture is carried out to determine the optimal oil-rock ratio And the best construction temperature,and evaluate its warm mixing effect;(4)Evaluation of the three road performance of waste plastic cracking wax warm mixing asphalt mixture.Asphalt binder research shows that WMa-1 and WMa-2 have good compatibility with matrix asphalt,without segregation;WMa-1 can improve the high temperature performance of asphalt,while WMa-2 can improve the low temperature performance of asphalt;WMa-Both 1 and WMa-2 can effectively reduce the high-temperature viscosity of asphalt,and the viscosity-reducing effect of WMa-2 is more significant,but WMa-1can also increase the low-temperature viscosity of asphalt while reducing the hightemperature viscosity of asphalt,and is more suitable for asphalt temperature.Mixing agent;when the blending amount is 6%,the comprehensive performance of WMa-1 warm mix asphalt is the best,so the optimal blending ratio is determined to be 6%;in addition,at this blending amount,WMa-1 warm mix asphalt has a good performance Resistance to thermal aging and storage stability.Microscopic studies have shown that the mechanism of action of waste plastic cracking wax and asphalt is physical blending,which reduces the high temperature viscosity of asphalt due to its good dispersion and lubrication effects.Asphalt mixture test shows that the optimal oil-stone ratio of AC-13 C waste plastic cracking wax asphalt mixture is 4.8%,and the optimal rolling temperature is about 116 ℃,which is about 24 ℃ lower than ordinary hot mix asphalt.In terms of road performance,Waste plastic cracking wax can effectively improve the high temperature stability of asphalt mixtures,but it has a certain negative impact on low temperature crack resistance and water stability.