Study On The Influence Of OMMT On The High And Low Temperature Performance Of Base Asphalt And SBS Modified Asphalt

Asphalt mixture mainly consists of aggregates and asphalt binder as basic materials and ingredients.Asphalt binder is mainly used for binding purposes in asphalt mixture.The increase in traffic loads and extreme climatic conditions either in high-temperature regions or low-temperature regions are the main causes for failure in asphalt pavements.Rutting,fatigue cracking,low-temperature cracking,potholes,and bleeding of asphalt are common distress seen in the asphalt mixtures.This type of distress will reduce the bearing capacity of the asphalt pavement and affects the quality of pavement service.The properties of asphalt mixtures also change over time during in-service life.As the failure of asphalt pavement is likely to occur,there is a need of increasing the lifespan for asphalt pavement and it can be achieved by improving the quality of materials and ingredients that are used in asphalt pavement.According to needs for improvement,different types of modifiers can be used to modify the physical and chemical characteristics of asphalt binders to improve the performance of asphalt mixtures.Organo-montmorillonite(OMMT)was used to modify the base asphalt(AH90)and Styrene-Butadiene-Styrene(SBS)modified asphalt.The penetration test,softening point test,rotational viscosity test,and ductility test was used to conduct the conventional performance of OMMT modified asphalt and SBS-OMMT compound modified asphalt.The rheological properties of OMMT modified asphalt and SBS-OMMT compound modified asphalt was analyzed adopting the Dynamic Shear Rheometer(DSR)and Bending Beam Rheometer(BBR).All the physical and rheological properties associated with the unmodified and modified asphalts were determined by conventional tests such as penetration depth test,softening point test,viscous measurement test,ductility test,Dynamic Shear Rheometer(DSR),and Bending Beam Rheometer(BBR).Rotating Thin Film Oven Test(RTFO)was employed to stimulate and explore the effect of the short aging process on modified and unmodified asphalt.The result showed that the effect of adding OMMT would decrease penetration depth,increased softening point,increased viscosity value,decreased ductility value,and increased rutting resistance for both aged and unaged types of asphalts which suggest that upgrade in high-temperature rutting resistance capability.However,adding OMMT would display negative effects on the low temperature cracking properties for all unmodified and modified asphalts.Based on the comparison of physical properties studied between base asphalt and SBS modified asphalt,SBS modified asphalt showed better performance than base asphalt.Thus,the mechanical tests were performed comparing SBS modified asphalt binder in asphalt mixture and its modification with OMMT added at a different percentage(0%-6%)by weight of asphalt taken.Based on high and low-temperature performance,water stability of asphalt tested,the result showed that adding OMMT to the SBS asphalt mixture can improve its high-temperature rutting resistance.The low-temperature anti-cracking performance of the asphalt mixture was tested at-10℃ tensile splitting test which proved with the addition of OMMT,the low-temperature anti-cracking performance of SBS modified asphalt mixture decreased slightly.Through the water immersion Marshall Test,it was concluded that after OMMT was added to the SBS asphalt mixture,the residual stability value increased with an increase in the OMMT content.SBS asphalt mixture with 4%OMMT content has both good water resistance and high water stability.However,the anti-aging performance of the asphalt mixture is not significantly improved after OMMT is incorporated.