Study On Road Performance Of Casting Modified Asphalt Mixture

The casting asphalt concrete has good compactness,durability,fatigue crack resistance and follow-up deformation ability,which can adapt to the essential requirements of steel bridge deck pavement,and has a good protective effect on the bridge structure.In this paper,four kinds of casting asphalt binders are selected(polymer composite modified asphalt,natural asphalt composite modified asphalt,modified hard asphalt(30 # asphalt)and modified hard asphalt(60/80 # asphalt))used in MAfor comparative analysis of the combined properties of asphalt binders and mixes.Through the comparative analysis of the basic performance of asphalt binding material,polymer composite modified asphalt and natural asphalt compound modified asphalt due to the mixing of polymers such as SBS,significantly improve the softening point of asphalt binding material,rutting factor,low temperature elongation and residual needle intake ratio,and thus improve the high temperature performance,low temperature ductility and aging resistance of asphalt binding material.Two kinds of hard-to-modify asphalt,because of the use of low-label hard asphalt or natural hard asphalt,its low temperature ductility is poor,and its aging performance declines faster.Through the matching ratio design of various pouring asphalt mixtures,a reasonable ratio of mineral grade and optimal oil-stone ratio is determined,and the performance of four mixtures is compared on this basis.Under the optimal oil-stone ratio condition,the liquidity of the four mixtures met the requirements,of which the polymer composite modified asphalt pouring asphalt mixture was the best liquidity.The high temperature stability of polymer composite modified asphalt pouring asphalt mixture is better than that of the natural asphalt compound modified asphalt pouring asphalt mixture and two kinds of hard-material modified asphalt pouring asphalt mixture,with a sling of less than 3.0mm at 60 C and less than 0.3mm in the 60 C percent increment of 60 C.Polymer pouring asphalt mixture has a very good low temperature bending performance,its limit low temperature bending strain in the four mixtures of the largest,reached 10000,followed by the natural asphalt compounding modified asphalt pouring asphalt mixture,and the two kinds of hard-to-modified asphalt pouring asphalt mixture limit bend ingest strain is small.Polymer composite modified asphalt pouring asphalt mixture has excellent fatigue performance,obviously better than two kinds of hard modified asphalt pouring asphalt mixture,its fatigue life of 600 microstrain conditions is greater than 1 million times.Polymer composite modified asphalt and its pouring asphalt mixture have excellent comprehensive use performance,and in Yunnan Longjiang Bridge steel bridge paving project has been applied,the implementation effect is good.In the construction of the solid steel bridge surface,the appropriate pouring asphalt combination and its mixture should be selected according to the engineering characteristics,service environment and design documents.