Research Of The Decay Law Of Ageing On The Cohesive Strength Of Asphalt At Low Temperatures And Mechanism Analysis

Along with the rapid development of national economy, vehicle speed isimproved continuously, traffic volume is continued rapid growth, more and more largevehicles are used, the rates of overloaded vehicles and overloading are increased, thoselead to the present stage of asphalt pavement must have higher performance, higherdurability, and the safer driving environment should be provided. But before the asphaltpavement using, the mixture need to be deal, such as hot mix and pave etc, which leadthe asphalt pavement was aging in a certain degree before formal opening. Meanwhile,the low temperature performance of asphalt surface has also become a important indexof asphalt pavement performance in the cold region. A lot of road survey data show thatthe low temperature cracking of asphalt pavement is one of the serious problems of thecommon road engineering, especially in cold areas.This paper focuses on the decay rule of the asphalt cohesive strength at lowtemperature in the aging process. From the Angle of the test of asphalt cohesive strengthat low temperature, the SBS modified asphalt and PE polymer modified asphalt whichhave been widely applied are analyzed. First the two kinds of experimental asphalt wereaging in rotating thin film oven. Then by using asphalt low temperature cohesivestrength quantitative testing technology, test the low temperature cohesive strength ofthe SBS and PE under different low temperatures and different aging time (aging time is6h,18h,24h,48h, the experimental temperature were selected to-5℃，-10℃，-15℃，-20℃，-25℃), and get the two kinds of asphalt low temperature cohesive strengthdecay curve, according to the asphalt aging decay curve speculated the timing of theembrittlement at different state of aging. The experimental results showed that thelength of the aging time has significant effect on the decay law of the SBS modifiedasphalt and PE polymer modified asphalt adhesive strength at low temperature. Thepeak temperatures of asphalt adhesive strength were different which due to the differentaging condition, the aging leads to the phenomenon which the embrittlement time ofthe two kinds of asphalt advanced. Through the four components separated experimentof asphalt and measured the content of components under different aging degree, further prove that the aging process causes a loss of the lightweight component of polymermodified asphalt, the Embrittlement timing of asphalt occurs in advance, which leads tothe sharp attenuation of low-temperature cohesive strength of asphalt, Anti-agingtechnology and asphalt lighter components pre-supplement technology should conductin-depth research.