Study On The Anti-rutting Technology For Uphill Sections Of Long And Large Longitudinal Slope Of Asphalt Pavement

Compared with flat slope sections of asphalt pavement, the action time that low-speedvehicle load to uphill sections of long and large longitudinal slope is much longer, in thecondition of comprehensive combination of heavy load and high temperature, the rutting onuphill sections of long and large longitudinal slope has faster speed of development andformation.Carrying on the comprehensive research on the anti-rutting of asphalt pavement withuphill sections of long and large longitudinal slope, which is necessary for solving andeffectively control the rutting problem.The results of field survey show that:(1) the rutting and push is main types of pavementdistress with uphill sections of long and large longitudinal slope, which develop easily thatprobably rapid forming in the highest temperature of the summer for one or two weeks. underthe high temperature, combined with heavy load and low speed load, usually the rutting depthin the uphill sections of long and large longitudinal slope is2~3times than other sections.(2)the deepest rutting lies in middle layer, the second lies in surface layer.(3) The highesttemperature is over60℃in the asphalt pavement structure.(4) Overloaded truck speed afterthe fall on uphill sections of long and large longitudinal slope has maintained at20~30km/huntil the uphill sections top.On the basis of rutting occurrence of uphill sections of long and large longitudinal slopeand the statistics of truck speed, this paper argues that the speed of full truck as thedefinition indicator for uphill sections of long and large longitudinal.With the finite element modeling calculation, analysis the mechanical response andrutting formation mechanism of uphill sections of long and large longitudinal slopecomprehensively, analysis the influence of gradient (component), speed of vehicle, overloadto uphill sections of long and large longitudinal slope of asphalt pavement, it shows that thestress of asphalt pavement has bigger growth with the lower speed, growth effects to stresscondition for the slope itself is smaller, but the slope effect on the rutting mainly leads to thedecrease of heavy vehicle speed resulting in increase of effect time of vehicle load and asphaltpavement.It adopts the new rutting test equipments that the load and wheel speed can be changed tosimulate the influence of overload vehicles speed change(loading time) on the rutting, theresults show that the load size, loading time and temperature have an equivalent effect. And the asphalt mixture designing by standard rutting test condition is very easy to form therutting under heavy load, high temperature, low speed condition, and it shows that thetemperature conditions (60℃) in specification to verify the high temperature stability ofasphalt mixture for uphill sections of long and large longitudinal slope is very unreasonable.With multilevel multilevel interlocked-dense gradation design method and Superpavemethod for asphalt mixture design, through the Hamburg wheel tracking test and MMLS3accelerating wheel tracking test, analysis and evaluate the anti-rutting performance ofdifferent asphalt (containing the additive agent), different types of asphalt mixture underdifferent load, temperature conditions, then recommend the asphalt mixture type and therelevant technical indexes for uphill sections of long and large longitudinal slope.On the basis of field investigation and analysis on the loading characteristics of uphillsections of long and large longitudinal slope of asphalt pavement, make it clear that therutting on asphalt pavement mainly formation in the surface layer and middle layer, based onaccelerated loading test results for reasonable pavement structure combination and thicknessdesign, then put forward the suitable asphalt pavement structure for uphill sections of longand large longitudinal slope of asphalt pavement.On the basis of traffic management, put forward some practicable measures to reduce therutting like that water cooling during the summer high temperature, setting up exclusiveclimbing lane, adjusting lane coefficient and overload vehicles pass in different time.