Research On Function Division Theory And Optimum Structural Design Of Semi-rigid Based Asphalt Pavement

Project practice shows that the highway with semi-rigid based asphalt pavement hasinsufficient durability, causes are complicated, the pavement structure is the key factor.Currently the problem that the pavement structure design disjointed with material design isstill remaining. To avoid pavement early damage, this paper systematic analyzed the differentsurface layers function partition of the semi-rigid based asphalt pavement and reasonablepavement structure combination.First analyzed the formation mechanism of fatigue cracks, rut and low temperaturecontraction cracks, then established the mechanical analysis model and researched on thevertical distribution law of internal stretching stress, shear stress and contraction stress at lowtemperature. The tensile stress in the asphalt surface layer is gradually increasing along thedepth direction, obtain the maximum in the underlying of surface layer, the internal tensilestress peak distribution area is located below the surface layer, according to this we candetermine the anti-fatigue area of semi-rigid asphalt pavement; the internal shear stress isgradually increasing from both the top and the bottom of the surface layer to the centrallocation of the surface layer which is some6cm from the top, obtain the maximum in the midof surface layer, the internal shear stress peak distribution area is located mid the surface layer,according to this we can determine the anti-rut area of semi-rigid asphalt pavement; theinternal contraction stress at low temperature is gradually increasing from the bottom to thetop of surface layer, obtain the maximum on the top of surface layer, the internal contractionstress at low temperature peak distribution area is located top the asphalt surface layer,according to this we can determine the semi-rigid asphalt pavement resist-area to lowtemperature shrinkage crack. This paper studied on the basic requirements of structure layerssemi-rigid based asphalt pavement both at home abroad, to define the surface layerfunction division: resist the low temperature contraction stress area, pavement surfacefunction area, anti-rut area and anti-fatigue area.Then according to the asphalt pavement layer function division theory, aimed to let everysemi-rigid asphalt pavement structural layers to reach the fatigue life at the same time, to meetboth the functional and the structure ability need and assure that not to produce a structural damage. Propose a reasonable structure combination and layer thickness.At last based on semi-rigid asphalt pavement structure optimization design and makefull use of the old pavement materials for rebuilding, make an optimized design of TianjinJin-bin highway renovation and expansion project, arrive at a final program by technical andeconomic comparison analysis.