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和钢筋混凝土（RC）桥面组成。在恶劣的环境中，比如在美国北部或加拿大的气候中，由于冬季天气大量使用除冰盐，甲板上形成了高度腐蚀的环境。超高性能混凝土（UHPC）的发展为工程师们提供了一个新的设计水平，创造出具有高强度和更长的设计寿命的更薄的截面。通过在混合物中添加有机纤维或钢纤维，消除了钢筋，从而简化了UHPC在建筑中的使用。作为新兴材料，纤维增强聚合物（FRP）复合材料作为钢的替代品，已成为新兴建筑的热门材料。玻璃钢桥面系统的重量约为类似钢筋混凝土桥面的20%。然而，尽管FRP具有优势（如高强度重量比、耐腐蚀等），但全FRP桥面系统（相对于RC桥面）较高的初始施工成本仍然是FRP在桥梁建筑市场广泛采用的主要障碍之一。因此，以混合结构体系的形式，充分利用FRP复合材料的独特性能和UHPC的独特性能，开发具有成本效益的高性能结构体系是至关重要的。拟议的FRP-UHP混合混凝土截面由薄壁玻璃钢挤压中空箱形截面与压区浇筑的超高压混凝土薄层和拉区粘结的碳纤维玻璃钢或玻璃钢薄板组成。高刚度和高强度部分的重量约为等效RC构件的1/3，可以在工作现场快速部署和安装。本研究计划将研究该系统在室温和低温下的静态、疲劳和长期载荷下的性能。这项研究将为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，该系统有可能取代传统的钢梁混凝土桥面，或作为自支撑的短跨度桥梁上层结构。

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.