Effect of different axle configurations on fatigue life of asphalt concrete mixture

The fatigue life of an asphalt mixture under different truck axle configurations was determined directly from the indirect tensile cyclic load test by using load pulses that were equivalent to the passage of an entire axle group or truck. The dissipated energy approach was adopted in analyzing the results and determining the number of repetitions to failure for each case; a unique fatigue curve that can be used for multiaxle configurations was developed. Trucks consisting of up to 11 axles and axle groups of up to 8 axles were studied. The results indicated that the normalized damage per load carried decreased with an increasing number of axles within an axle group. Additionally, the fatigue lives predicted by using single load pulses were compared with the measured ones from the different axle groups and trucks.