Investigation of Top-Down Cracking in Asphalt Pavements Using FEM

Top-down cracking (TDC) is among the major forms of asphaltic pavement distresses that significantly affects the serviceability and development of structural failure. Interaction of tire and pavement interaction plays a key role in the initiation of TDC. This study utilizes viscoelastic analysis using finite element modeling to evaluate the influence of axle loads and tire types on the top down cracking in asphaltic pavements. The effect of three axle loads of 5, 8.2 and 15 ton and two tire configurations (conventional dual tire assembly and super single tire) on TDC in Geogrid reinforced and unreinforced pavements has been investigated. The results show that under axle load of 5 and 8.2 ton top down cracking occurs, initialy at the inner edges of the tires, while under axle load of 15 ton its occurence between the tires is sooner than the other zones. Among bottom-up cracking (BUC) and TDC, BUC is more sensitive to the variations of tire type. The study also indicates that the reinforcement of pavement using geogrid at the bottom of asphalt layer is more effective on the bottom up cracking than on the top down cracking. By comparison, the super single tire was shown to create more TDC damage ratio than the dual tires assembly in both reinforced and unreinforced pavements.
Top-down cracking (TDC) is among the major forms of asphaltic pavement distresses that significantly affects the serviceability and development of structural failure. Interaction of tire and pavement interaction plays a key role in the initiation of TDC. This study utilizes viscoelastic analysis using finite element modeling to evaluate the influence of axle loads and tire types on the top down cracking in asphaltic pavements. The effect of three axle loads of 5, 8.2 and 15 ton and two tire configurations (conventional dual tire assembly and super single tire) on TDC in Geogrid reinforced and unreinforced pavements has been investigated. The results show that under axle load of 5 and 8.2 ton top down cracking occurs, initialy at the inner edges of the tires, while under axle load of 15 ton its occurence between the tires is sooner than the other zones. Among bottom-up cracking (BUC) and TDC, BUC is more sensitive to the variations of tire type. The study also indicates that the reinforcement of pavement using geogrid at the bottom of asphalt layer is more effective on the bottom up cracking than on the top down cracking. By comparison, the super single tire was shown to create more TDC damage ratio than the dual tires assembly in both reinforced and unreinforced pavements.
Top-down cracking (TDC) is among the major forms of asphaltic pavement distresses that significantly affects the serviceability and development of structural failure. Interaction of tire and pavement interaction plays a key role in the initiation of TDC. This study utilizes viscoelastic analysis using finite element modeling to evaluate the influence of axle loads and tire types on the top down cracking in asphaltic pavements. The effect of three axle loads of 5, 8.2 and 15 ton and two tire configurations (conventional dual tire assembly and super single tire) on TDC in Geogrid reinforced and unreinforced pavements has been investigated. The results show that under axle load of 5 and 8.2 ton top down cracking occurs, initialy at the inner edges of the tires, while under axle load of 15 ton its occurence between the tires is sooner than the other zones. Among bottom-up cracking (BUC) and TDC, BUC is more sensitive to the variations of tire type. The study also indicates that the reinforcement of pavement using geogrid at the bottom of asphalt layer is more effective on the bottom up cracking than on the top down cracking. By comparison, the super single tire was shown to create more TDC damage ratio than the dual tires assembly in both reinforced and unreinforced pavements.