Study On The Performance Of Warm-mix Amorphous Poly Alpha Olefin Modified Asphalt And Mixture

Amorphous Poly real AlPha Olefin(APAO)as a kind of thermoplastic rubber class modifier,not only can improve the high temperature resistance to deformation ability of asphalt and mixture,but also has a positive effect on reducing temperature sensitivity of asphalt and improving low temperature crack resistance of asphalt mixture.However,there are some obvious shortcomings in APAO modified asphalt,such as high viscosity,high mixing and compaction temperature during construction,and easy to produce short-term aging.The warm mix additives Sasobit and Deurex have a good viscosity reduction effect on asphalt,thus reducing the mixing and compaction temperature of asphalt mixture.Based on the characteristics of the above-mentioned two kinds of additives and the principle of adhering to the combination of resource development and saving,this paper puts forward the advantages of the composite modification of asphalt by APAO/Sasobit and APAO/Deurex.The main contents of this paper are as follows:First of all,through the conventional performance test,the rheological properties test and aging performance test of asphalt to initially decide the modification effect of Sasobit/APAO and Deurex/APAO warm mix modified asphalt and reasonable dosage range.The results show that the addition of Sasobit and Deurex make the high temperature stability,workability and anti-aging propertie of APAO modified asphalt significantly improved.However,excessive amount of dosage will have adverse effects on its low temperature flexibility.The content of Sasobit and Deurex should not exceed 4% in terms of high and low temperature improvement of asphalt and economic benefits.Secondly,the interaction mechanism between Sasobit,Deurex and APAO modified asphalt was explored by using infrared spectroscopy to analyze the chemical composition and microstructure before and after APAO modified asphalt warm mix.The results show that after adding Sasobit and Deurex in APAO modified asphalt,the absorption peaks of 3600~3730cm-1 disappeared,and the chemical reaction might have occurred in the mixing process.The disappearance position of the peak was different,it is indicated that the composition of Sasobit and Deurex is different,and the effect on the APAO modified asphalt also is different.Finally,a test group with a 2~4% better dosage range is used to evaluate the performance of warm mix asphalt mixtures,and through the asphalt mixture' highand low temperature performance test,volumetric performances test,water stability test and long-term aging performance test to verified the effects of Sasobit and Deurex.The results show that the appropriate mixing additives dosage has positive significance for improving the performance and durability of APAO modified asphalt mixture.From the comprehensive consideration of the construction workability,mechanical performance,durability and economic benefits of asphalt pavement,4%Sasobit and 2% Deurex is the optimum amount of asphalt mixture used in this study and they have significant improvement effects on high temperature performance and low temperature performance respectively.