Investigating the Performance of Cracked Asphalt Pavement Using Finite Elements Analysis

Occurrence of top down and bottom up fatigue cracking in asphaltic pavements is common. Conventional pavement analysis methods ignore the existence of cracks in asphaltic layers. However, it seems that the responses of cracked pavement would not be the same as a pavement without crack. This paper describes effects of crack type, position and length, and vehicles tire inflation pressure and axle load on the performance of cracked asphalt pavement. Tensile strain at the bottom of asphaltic layer, the vertical strain on subgrade, maximum deflection on the surface, rut depth and the stress intensity factors of cracked pavement, with top down and bottom up crack have been computed using 3D Finite Elements method in ABAQUS. Moving load of standard single axle with different loads and tire pressures have been used in the analysis. Standard 8.2 ton single axle load at different tire pressures of 552(80), 690(100), 828(120) and 1035(150) kPa(psi) and single axle at different loads of 5, 8.2 and 15 ton, all at the same tire pressure of 690 kPa, have been used. Results show that the pavement responses increase with increasing tire pressure and axle load with higher values and rate of increase with increasing tire pressure and axle load for the cracked pavement compared with the pavement without crack. For the pavement structure investigated in this study, it was found that, in general, top down crack results in higher responses than bottom up crack.