Study On Road Performance And The Mix Proportion Design Of Fine Aggregate Ultra-thin Asphalt Mixture

It becomes a urgency for western district to find out how to design asphalt pavement with good durability and use quality within limited finance. Ultra-thin asphalt concrete pavement has excellent economic and social benefits, under the background of advocating for sustainable development, ultra-thin asphalt concrete pavement will get more and more widely used in China. This paper reports the in-depth research on mix proportion design and road performance of fine aggregate ultra-thin asphalt mixture.Through the correlation analysis of factors affecting the shear strength of the materials, the author takes the friction angle as the primary index which can evaluate the skeleton strength of coarse aggregate perfectly. According the coarse aggregate- asphalt mortar mix uniaxial penetration test and ram density test, the coarse aggregate gradation design method is brought forward based friction angle and heap. Combining fine gradation design philosophy of SAC with coarse aggregate grading design method, the mix design of strong skeleton fine-grained ultra-thin rubber asphalt mixture is proposed.The effects of different gradations, different additives, different paving conditions on road performance of the asphalt mixture are analyzed by the routine road performance testing. The influence of the paving conditions to the hot-temperature stability of asphalt mixture is especially studied. Based on the mixture routine road performance the suitable mix composition is put forward.On the basis of analyzing the damage of ultra-thin asphalt pavement, the author considers the reasons of failure to be higher unit thickness of traffic pounding load and more connective gaps. The durability is systematically analyzed by an indicator D(pounding–freeze-thaw damage degree) with an apparatus that invent by the author.The effects of different gradation, different asphalt, different thicknesses of asphalt mixture are studied through pounding–freeze-thaw testing. The recommended asphalt mix composition is presented.Based on the tests of the skid-resistance and tire/pavement noise, the influences of the different factors on the surface function of ultra-thin asphalt pavement are analyzed. The durability of the road skid-resistance is evaluated by the indicator Eeff(long-term benefits value of pavement safety), the suitable composition for skid-resistance and tire/pavement noise asphalt mixture is recommended.The applicability of fine-aggregate ultra-thin asphalt pavement is verified by test road design, construction and test, with different paving thickness, asphalt and additive dosage paving programs.