Deterioration of concrete pavement subjected to coupled fatigue loading and hydrodynamic scouring

Fatigue loading and hydrodynamic pressure generated by the repetitious action of moving wheels cause concrete pavement that contains Portland cement, i.e., Portland cement concrete (PCC) pavement, to undergo significant deterioration at the surface and interior. In this experimental study, a device equipped with wheels and a water pump was designed to simulate the coupled effect of fatigue loading and hydrodynamic scouring on PCC pavement. The hydrodynamic pressure was measured by a sensor under conditions involving different vehicle types and speeds. The effects of the stress level, fatigue cycle number and hydrodynamic pressure on the flexural strength, dynamic modulus, chloride diffusion coefficient and British pendulum number (BPN) of PCC were determined. The results showed that the hydrodynamic pressure was closely related to the vehicle type and speed, and trucks produced greater hydrodynamic pressure than cars moving at the same speed. The maximum pressure applied by trucks was 507.81 kPa at 80 km/h. Fatigue loading was the main cause of mechanical PCC damage; speed led to decreases in the flexural strength and dynamic modulus, whereas hydrodynamic scouring played the dominant role in the resistance of PCC to penetration by chloride ions.