New bridge construction using an innovative hybrid FRP-UHP concrete deck systems

点击翻译按钮获取中文摘要

Bridge superstructures consist of concrete or steel girders topped with a reinforced concrete (RC) deck. In harsh environments, such as those found in northern US or Canadian climates, a highly corrosive environment develops in the decks, attributed to the heavy use of deicing salt during winter weather. The development of Ultra High Performance Concrete (UHPC) provides engineers the opportunities of a new level of design to create thinner sections with high strength and longer design life. The use of UHPC for construction is simplified through the elimination of reinforcing steel by adding organic or steel fibers to the mix. As emerging materials, Fibre Reinforced Polymer (FRP) composites have been introduced as attractive materials for new construction as a substitute for steel. An FRP bridge deck system could weigh about 20% of a similar RC deck. However, in spite of the advantages offered by FRP (such as high-strength to weight ratio, corrosion resistant, etc.,), the higher initial construction cost of full FRP bridge deck systems (relative to RC deck) is still one of the major obstacles for wide-spread adoption of FRPs in the bridge construction market. Therefore, it is essential to develop cost-effective high-performance structural systems that take full advantage of the unique properties of FRP composites and the distinctive properties of UHPC in the form of hybrid construction system. The proposed hybrid FRP-UHP concrete section consists of a thin-walled Glass FRP pultruded hollow box section combined with a thin layer of UHP concrete cast in the compression zone and a thin Carbon FRP or Steel FRP sheets bonded in the tension zone. The high stiffness and strength section could weigh about 1/3 of an equivalent RC member that allows for rapid deployment and installation at the job site. This research program will investigate the performance of the proposed system under static, fatigue, and long-term loading at room and low temperatures. This research will bring a new technology to the industry that permits the use and construction of durable hybrid bridge deck systems that have the potential to replace conventional concrete bridge decks on steel girders, or to serve as a self-supported short span bridge superstructure.