The Mechanism Of Void Evolution And Fatigue Damage On Cement Concrete Pavement With Hydrodynamic Pressure

With the rapid development of national economy, the standard on the roadquality gets higher and higher.The cement concrete pavement was widely used as ahigh-grade road. Because of frequent overload, the cement concrete pavement wasdestroyed heavier and heavier, and its life got lower. Many domestic and foreignresearches said that early damage of cement concrete pavement was caused by theexpansion of void areas with board bottom hydrodynamic pressure cycle, in additionto the overload factor. The microscopic mechanism of void evolution and fatiguedamage on cement concrete pavement with board bottom hydrodynamic pressurecycle was useful and effective to extend the life of the road and improve theperformance of pavement.In order to research hydrodynamic pressure of the empty region in board bottom,the technology of Fiber Bragg Grating was used in small-scale simulation and fieldtest, and the influence of various factors on hydrodynamic pressure was obtained.Through literature and results of experiments, the microscopic mechanism of voidevolution on cement concrete pavement with board bottom hydrodynamic pressurecycle was researched, and the influence of various factors on void evolution wasobtained. Relying on Tanshao highway, the pavement structural model of3D finiteelement was established, which was under the void state. Load stress of concretepavement with different void size and different axle load was calculated by softwareABAQUS. Calculation formula of load stress was calculated though statisticalregression of the results, which applied to concrete pavement of Tanshao highway.The influence of void evolution on fatigue stress of cement concrete was analyzed.The accumulative number of fatigue damage under void state was calculated. Tanshaohighway was analyzed.The mechanism of void evolution with hydrodynamic pressure cycle was furtherrevealed in this paper, which was necessary to deeply research the influence of voidevolution on fatigue damage and so on.