Study On The Performance Of Industrialized Rubber/SBS Composite Modified Asphalt(CR/SBSCMA) And Asphalt Mixture In Seasonal Freezing Regions

Special climatic conditions in seasonal frozen region makes asphalt pavement face serious challenges, particularly performance in low temperature and frost resistance has higher requirement. However,the single crumb rubber modified asphalt has such problems as high viscosity, construction quality difficultly to control etc. Waste rubber powder and SBS composite modified asphalt(CR/SBSCMA) mixture has good performance with both economic and social benefits, which can solve the problems above. But the production in field faces performance variation, high costs and poor storage stability problems. Under the background this paper mainly carries out systematic studies including the factory production, conventional performance of CR/SBSCMA, mixture performance, mechanical characteristics and construction technology.First, considering the characteristics of rubber powder and SBS, the paper systematically analyzes materials parameters and technological parameters for industrialized CR/SBSCMA. The key control parameters such as rubber powder fineness, rubber powder dosage, SBS dosage and reaction temperature and reaction time and so on are proposed for the production of industrialized CR/SBSCMA. At the same time, through the evaluation method of macro performance test and microstructure analysis evaluation, using conventional indicators such as penetration, softening point, ductility, viscosity, elastic recovery etc. and scanning electron microscopy(SEM), differential thermal analysis and infrared spectrum test methods to discuss CR/SBSCMA performance and microscopic morphology features. On the baisi of climate requirement and test result, technical indexes suitable for industrialized CR/SBSCMA in season frozen region are put forward.On the basis of the principle of rheology, dynamic shear rheological tests are conducted for industrialized CR/SBSCMA and SBS modified asphalt in different temperature(64 ℃, 70 ℃, 76 ℃) and different frequency range(0.01 Hz~16 Hz). The mechanic property in high tempereture in different temperature for two kinds of modified asphalt is analyzed taking rutting factor as evaluation index. According to the time and temperature equivalence principle, modulus master curves are built, the mechanical characteristics for two kinds of modified asphalt under different conditions of temperature are gained. Also creep test are carried out under different temperature(24 ℃,-18 ℃,-30 ℃). The creep property is analyzed through the change rule creep stiffness modulus m and stiffness S for two kinds of modified asphalt. In addition, analysis on viscosity-temperature property are developed in different temperatures(135 ℃, 175 ℃, 200 ℃). And the analysis results of rheological behavior above show that the CR/SBSCMA has good rheological properties.In order to give full play to the performance of the CR/SBSCMA mixture based on the CR/SBSCMA characteristics itself, aggregate gradation curve for CR/SBSCMA in seasonal frozen region. In the meantime, the conventional dynamic stability test, low-temperature bending test and water stability test for two kinds of mineral aggregate gradation AC and SMA asphalt mixture are conducted. And Hamburg rutting test and low temperature frozen off test are carried out to evaluate the performance of CR/SBSCMA mixture. Combined with the traffic and climate characteristics in seasonal frozen region, the performance indexes suitable for industrialized CR/SBSCMA mixture in season frozen region are put forward, which provides an important basis for industrialized production and large-scale application in season frozen region.Through static compressive strength, resilience modulus test and the low-temperature creep compliance test, the comparative analysis on mechanical properties of CR/SBSCMA mixture in different temperature scope are carried out. According to the time and temperature transformation law, the dynamic modulus principle curves are established and mechanical properties are analyzed in the whole frequency range. The results verify again industrialized CR/SBSCMA mixture has good ability to resist permanent deformation and good flexibility in low temperature condition.Finally, industrialized CR/SBSCMA mixture construction technology are systematically summarized through engineering built, which effectively guide the construction and application for CR/SBSCMA mixture in seasonal frozen region.