Experimental Study On Durability Of Lhfrc And Application On Pavement

Based on the analysis of superior and weak properties on plain concrete and only one fiber reinforced concrete .In order to improve the scarcity of toughness and durability of LSFRC more, layer-hybrid-fibers-reinforced-concrete(LHFRC) is offered . Much less steel fibers are evenly distributed on the surface and the bottom about 20 mm of the pavement slabs, the middle body of which is composed of polypropylene fiber concrete . This type of new composite material pavement will utilize the different mechanical behavior of steel fibers and polypropylene fibers. LHFRC has outstanding comprehensive mechanical behavior, durability and cuts the cost.In this paper, the effect of layered steel fiber and polypropylene fiber on osmosis, pore ratio and bending impact toughness of concrete is investigated by comparing tests on layered-hybrid-fiber-reinforced concrete with those on plain concrete, layered-steel-fiber-reinforced concrete. The tests result and analysis demonstrate that the osmosis, pore ration and the bending toughness of layered-hybrid-fiber-reinforced concrete are better than that of plain concrete and layered-steel-fiber-reinforced concrete. It is very important for durability of layered-hybrid-fiber-reinforced concrete.The reinforcing and failing mechanism of LHFRC are investigated. Then, the temperature stress of LHFRC pavement slab are calculated through finite element method(FEM) with Winkler's soil model. Finally an investigation was conducted on the design of one-layer-hybrid- fiber-reinforced-concrete. The analysis demonstrates that with the thickness of one-layer-hybrid-fiber -reinforced concrete decreased, that construction is more simple and cost is lower.The testing result and analysis demonstrate that the properties of concrete(anti-crack, toughness, durability etc.)are improved greatly by hybrid fiber, therefore, LHFRC can be widely applied to pavement and other fields.