Accelerated loading dynamic response of full-scale asphalt concrete pavement

The dynamic response of pavement structure under moving vehicle loads was measured by using the accelerated loading test facility of full-scale asphalt concrete pavement.The dynamic strain at the bottom of surface layer for the pavement and the vertical compressive stress at the top of subgrade were taken as analysis objects, and the influences of axle load, speed and tire pressure on the dynamic response were studied.The regression models among dynamic response, axle load and speed were established respectively.Four kinds of pavement structures were tested in different axle loads, speeds and tire pressures.Analysis result shows that under moving vehicle loads, the strain response at the bottom of surface layer is in the alternative condition of tensile strain and compressive strain.Under intermediate test temperature, the strain response at the bottom of surface layer increases linearly with the increase of axle load, the vertical compressive stress at the top of subgrade shows uniaxial stressed state, and it increases with the increase of axle load.Speed affects the strain response at the bottom of surface layer significantly, but it has little influence on the vertical compressive stress, and affects the stress pulse duration only, and the stress pulse duration and strain response at the bottom of surface layer reduce with the increase of speed.The destroy degree of pavement is more serious in low speed and heavy load, but tire pressure has little influences on the strain at the bottom of surface layer and the vertical compressive stress at the top of subgrade.