A Fatigue Damage Analysis of Composite Construction Composed Asphalt Concrete Pavement and Steel-Box Beam Deck of Steel Bridge

摘要

Asphalt concrete is road pavement material with excellent property and is widely used in the steel bridge pavement. The system of steel bridge pavement is a composite structure composed asphalt surface and steel-box beam deck. Investigation shows that steel bridge deck support the mainly load in this composite structure. Because steel has good character on resisting fatigue, damage mainly generate in the asphalt concrete pavement under the moving vehicle loads. Fatigue crack has become one of main disasters in the bridge pavement. The system of steel bridge pavement can be simplified into a model of composite beam under some condition. Based on the bending test of composite beam simple, the curve of deflection in the mid-span of composite beam vs the cycle number can be gained. Due to the damage accumulation in the asphalt concrete, the varieties of bending rigidity and mid-span deflection of composite beam in the fatigue process are studied by the method of damage mechanics. The control equations of fatigue damage are also developed. The prediction method of fatigue life of steel bridge pavement is discussed initially. The theoretical predictions are in good agreement with the experimental curve.