Steel Fiber Reinforced Concrete Deck Pavement Engineering Technology Research

In recent years, with the increase of traffic volume and heavy vehicle, the deterioration of bridge deck pavement is comparatively severer and the maintenance period is becoming increasingly shorter. Damages of bridge deck pavement emerge soon after opening to traffic, such as longitudinal, lateral and diagonal cracks as well as chuckhole, crackle and peeling. These problems not only disturb traffic safety, influence aesthetics of bridge deck, but also bring about biggish economic loss. Steel fiber reinforced concrete (referred as SFRC thereafter) is a kind of new constructional material and possesses many eximious performances. Owing to favorable crack resistance, flexural toughness, high impact resistance performances and so on, SFRC is extensively used in construction engineering. Engineering practices show that when SFRC is used in architecture it not only effectively reduces all kinds of cracks, defers crack appearance, but also enhances bonding strength of architecture structure, elongates service life of construction, and therefore strengthens stability and reliability of monolithic construction. Combining practical engineering, material properties of SFRC and mechanical characteristics and building technology of bridge deck pavement and so on are systematically studied in this thesis, and principal research findings obtained is as follows:1. Through data searches and preliminary experimental study, strengthening mechanism, technical performance and static load mechanics characteristic of SFRC are probed into. Based on which, through experiment research of compressive strength, tensile splitting strength, bending strength and flexural toughness of two kinds of SFRC, the influence of steel fiber contents and types on concrete mechanics performance are analyzed, and consequently reliable technical foundation is supplied for ascertaining SFRC mix ratio suitable for bridge deck pavement characteristics.2. Through static experiments of full-scale one-way and two-way SFRC and reinforced concrete (referred as RC thereafter) slabs under concentrated load, simply supported along its two opposite edges, their mechanical properties and failure modes are discussed. By comparing performance differences of the two kind of concrete slabs, performance influence of steel fiber on resisting and blocking fissure as well as toughness of concrete members in flexure are detailedly analyzed. By transforming load acting location and load acting area, the influenceof load acting mode on mechanical properties of RC slab and SFRC slab is studied. Based on which, the feasibility of SFRC partly superseding RC is probed into bridge deck pavement.3. Integrating relative specifications, construction technique of SFRC bridge deck pavement is analyzed. Based on experiments and computational analysis, we apply SFRC to loyang huai village Zhong Bridge (assembled hollow-core Slab Bridge). Through practical application, operating performance of SFRC material and the reasonability of design method of bridge deck pavement are analyzed, and comparatively satisfactory effects are obtained.As a new constructional material, although SFRC can overcome many disadvantages and insufficiencies of plain concrete, the cost of which is comparatively higher and therefore its application is restrained. With the development of foundation establishments and the increase of construction investment, exploring new material and the exploitation and use of new technology in key projects of bridge, tunnel and so on will prolongate the service life of engineering structure, advance investment benefit and guarantee safe traffic passage. The research findings in the thesis supply certain technical base for extensive application of SFRC to bridge deck pavement and it not only possess significant theoretical value but also possess all-important instructional significance and practical value for engineering practice.