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

桥梁上部结构由混凝土或钢梁组成，顶部为钢筋混凝土（RC）桥面。在恶劣的环境中，例如在美国北方或加拿大气候中发现的那些，由于在冬季天气期间大量使用除冰盐，甲板中形成高度腐蚀性的环境。超高性能混凝土（UHPC）的发展为工程师提供了一个新的设计水平的机会，以创造具有高强度和更长设计寿命的更薄截面。通过在混合料中添加有机纤维或钢纤维来消除钢筋，从而简化了UHPC在建筑中的使用。纤维增强聚合物（FRP）复合材料作为一种新兴的材料，已经作为一种有吸引力的新型建筑材料被引入，作为钢材的替代品。FRP桥面板系统的重量约为类似RC桥面板的20%。 然而，尽管FRP提供了优点（例如高强度重量比、耐腐蚀等），全FRP桥面系统（相对于RC桥面）较高的初始建造成本仍然是FRP在桥梁建造市场中广泛采用的主要障碍之一。因此，必须开发具有成本效益的高性能结构系统，以混合结构系统的形式充分利用FRP复合材料的独特性能和UHPC的独特性能。建议的混合FRP-UHP混凝土截面由薄壁玻璃纤维增强塑料拉挤成型空心盒形截面与在压缩区浇注的薄层UHP混凝土和在拉伸区粘结的薄碳纤维增强塑料或钢纤维增强塑料片材组合而成。高刚度和强度部分的重量可以是等效RC构件的约1/3，这允许在工作现场快速部署和安装。该研究计划将调查所提出的系统在室温和低温下的静态，疲劳和长期负载下的性能。这项研究将为该行业带来一项新技术，允许使用和建造耐用的混合桥面系统，该系统有可能取代钢梁上的传统混凝土桥面，或作为自支撑的短跨度桥梁上部结构。

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.