Research On The Composite Steel Fiber Reinforced Concrete Pavement

Cement concrete pavement under the overloaded wheels repeated load is easy to produce cracks,because of the low flexural tensile strength and fatigue resistance, the small tensile deformation and thepoor crack resistance and impact resistance toughness. In addition to concrete slab in the wheel load,because its elastic modulus and mechanical strength is much higher than the corresponding modulus andstrength of the grass-roots and soil base, while the load along the depth in concrete slab internal dissipatesquickly, it’s easy to produce flexural tensile fracture along the bottom of the panel.A new type of composite steel fiber concrete pavement is put forward, based on the mechanicalcharacteristics of cement concrete pavement on Winkler foundation and the foundation on half space elasticlayered system and the performance of steel fiber concrete. Simulating biaxial load test and cost analysisabout the composite steel fiber reinforced pavement have been proceeded. The results show that:(1) Theflexural strength of composite steel fiber concrete pavement as similar with the traditional steel fiberreinforced concrete pavement is higher than ordinary concrete pavement’s and layered Steel Fiberreinforced concrete pavement’s. Simultaneously, compared with ordinary concrete pavement, the compositesteel fiber concrete slab shows ductility in damage, thus the brittle fracture at the bottom of pavementresulted by subgrade softening and slab hollow can effectively alleviate.(2) The cost of composite steelfiber reinforced concrete pavement is equal to ordinary concrete pavement’s and layered steel fiberreinforced concrete’s, but it is far less than traditional steel fiber reinforced concrete pavement’s.(3)Compared with layer steel fiber reinforced concrete pavement, Composite steel fiber reinforced concretepavement is more flexible, So we can rationally regulate the thickness and the volume fraction of steel fiberat the bottom of steel fiber reinforced concrete for different geological features, in order to achieve thereasonable use of resources. Finally, enhanced and failure mechanism analysis of composite steel fiberreinforced concrete pavement structure from macro and micro perspective are proceeded. The results showthat:(1) Composite steel fiber reinforced concrete pavement experience micro-cracks stage, Micro-cracksexpansion stage, Micro-cracks through stage and plate body destruction stage from its beginning to bearloads completely destroyed. In four stages, Steel fiber has obvious restraining effect on concrete cracks and expansion, thereby the comprehensive performance of the plate body has effectively enhanced. Meanwhile,Steel fiber plays a crucial role in the process of delaying plate body damage and improving the carryingcapacity.(2) On condensation early of the composite steel fiber concrete pavement, there will producesome Micro-cracks that can’t be avoided in the bonding interface between cement paste and aggregate. Theinteractions between these Micro-cracks and shrinkage stress generated by concrete creep process canaffect the fatigue strength and service life of composite steel fiber concrete pavement.