Research On The Properties Of Asphalts Modified By Waste Rubber Powder And Amorphous Poly Alpha Olefin

Waste tire rubber powder(WTR)as a kind of asphalt modifier,not only can be more comprehensive to improve the performance of asphalt,but also effectively alleviate the environmental pollution caused by waste tires.However,there are some obvious shortcomings of the waste rubber powder modified asphalt,such as waste powder particles and asphalt easily segregated,the storage stability is poor.Amorphous Poly AlPha Olefin(APAO)modifier has also a better asphalt modifier,it can not only easily with the asphalt melting,but also with the rubber immiscible,it can also be used for rubber modification.But its effect on the improvement of low temperature performance of asphalt is controversial.Considering the characteristics of the two modifiers,this paper proposes a complex modification of the WTR and APAO to combine the advantages of the two modifiers.The main contents of this paper are as follows:First of all,WTR/APAO modified asphalt is a new complex modified asphalt combination.this paper first through the preliminary experiment to determine the effect of its complex modification and the reasonable range of the two.And then the asphalt penetration,elastic recovery,ductility,softening point,viscosity as the indicators for the evaluation basis,getting the best processing technology including the reasonable order of adding WTR and APAO modifier,the parameters of the shear temperature,the shear rate time and shear speed.Secondly,in order to study the effects of WTR and APAO content on the conventional properties of complex modified asphalt,different dosage of WTR and APAO modified asphalt were prepared according to the optimal processing technology.In addition,the rheological properties and storage stability of complex modified asphalt were studied.Experimental results show:the high temperature performance and the recoverable deformation ability have been remarkably improved,and the temperature sensitivity of asphalt at high temperature,medium temperature and low temperature is significantly reduced.Under low temperature conditions,WTR/APAO complex modified asphalt has better flexibility,but the stress dispersion ability is worse.When the content of WTR and APAO is appropriate,the phase angle of WTR/APAO complex modified asphalt is a stage of platform change in the range of 50??60?,and the modifier has a continuous network structure in asphalt.It was found that the addition of APAO significantly improved the storage stability of Waste rubber powder modified asphalt by the segregation tube test and TG/DSC test.Finally,the aging performance of WTR/APAO complex modified asphalt was studied according to the conventional aging evaluation index.And the anti-aging properties and complex modification mechanism of WTR/APAO complex modified asphalt were studied by infrared spectroscopy.The results show,the complex modification of WTR and APAO to asphalt should be a combination of physical modification and chemical modification.The addition of WTR,APAO significantly improved the anti-aging performance of the asphalt.