Preparation And Application Research Of Hot Mix Asphalt Modifier

Asphalt pavements are proned to produce high-temperature rutting,low-temperature cracking,and water damage due to factors such as material,load,environment and structure.In this regard,using modified asphalt and added asphalt mixture modifiers are two common defense mechanisms.SBS and other polymer-modified asphalts have significant use effects,but they cannot be widely used at all levels of highways and pavement layers due to high cost and other reasons.Asphalt mixture modifiers based on polymers and external blends as the main components can achieve excellent results and have good economic benefits,but some modifiers have several defects like modification effect unilateral or poor long-term service performance.In view of some inadequacies of existing modification for asphalt and asphalt mixture,this article is dedicated to developing a comprehensive modifier for hot asphalt mixture.The modifier can significantly improve the high and low temperature performance and water stability of the asphalt mixture,with simple production process and easy to use,and it has the comprehensive advantages of resource conservation,environmental friendliness,and cost-effectiveness.Selecting LDPE,several other polymers,and two kinds of nanomaterials as initial research objects,to modified 70#base asphalt for each material.Comprehensively compared the effects of various materials on the high and low temperature performance and temperature sensing performance.The waste LDPE,and other three materials were filtered out as the four kinds of materials with the better comprehensive modification effect.Experiment on composite modified asphalt for the four materials that have been filtered by the orthogonal test,compared the comprehensive performance of 70#base asphalt with different compounding ratios of four materials,and filtered out three groups.Three modifiers Ma,Mb,Mc were formed according to the three groups by twin screw extruder.Used three modifiers modified 70#base asphalt for DSR test,the results show that three modifiers have a significant effect on the high temperature performance of the base asphalt.Selecting AC-20 as grading type,and 0.3%mass of HMA as the dosage of the modifiers,use three modifiers to modified HMA,carried out rutting test,uniaxial penetration test,low temperature bending test,low temperature creep test and freeze-thaw cleavage test,to research the effect of three modifiers on the road performance of asphalt mixture,and compare them with 70#asphalt and SBS asphalt HMA.The results show that three modifiers can all significantly improve the high temperature performance and water damage resistance of asphalt mixture,higher than SBS HMA,the Mc is superior to Ma and Mb in improving shear strength and crack resistance in low temperature,and each performance index exceeds or approache to SBS HMA.Comprehensive evaluated the application effect of three modifiers,analyzed each modification mechanism.,and Mc was identified as the best hot mix asphalt modifier finally.