Fibre reinforced polymer bridge decks: Sustainability and a novel panel-level connection

Licentiatavhandling, 2014

Fibre reinforced polymer (FRP) bridge decks have emerged as a competitive alternative to traditional decking solutions for the refurbishment of existing bridges, as well as the construction of new ones, in the past two decades. FRP decks offer inherent properties such as light weight, high strength and high resistance to aggressive environments. In addition, the prefabrication of FRP decks brings the benefits of industrial bridge construction and rapid on-site assembly leading to the minimisation of traffic disturbance. Even though the use of FRP decks started in the early 1990s, the uptake of these decks has been slow in bridge construction and there remains a need for research in diverse technical areas to promote the widespread use of these decks. The existing research and field applications of FRP decks were synthesised to recognize the standing level of knowledge and map out possible knowledge gaps. As an outcome several research needs were identified wherein two of them were: to determine the potential of bridges with FRP decks with respect to sustainability, and to develop connections which enable rapid on-site assembly. This thesis aims to contribute in bridging these knowledge gaps by investigating the sustainability of bridges with FRP decks and developing a novel panel-level connection for potential swift on-site assembly of FRP bridge deck panels. The sustainability of bridges with FRP decks was evaluated using life-cycle cost (LCC) analysis and life-cycle assessment (LCA) with a focus on carbon emissions. An existing steel-concrete bridge with a deteriorated concrete deck was selected as a case study. Two scenarios were studied and analysed: the total replacement of the bridge and a bridge rehabilitation scenario in which the concrete deck is replaced by an FRP deck. The analyses revealed that the latter scenario contributes to potential cost savings over the life cycle of bridges in addition to a reduced environmental impact in terms of carbon emissions. A novel panel-level connection was developed by following a process in which the client, designer, manufacturer and contractor were involved. Numerical analyses and experimental tests were conducted to investigate the overall structural behaviour and the load-carrying capacity of the developed panel-level connection. The results demonstrated that the connection exhibits sufficient load-carrying capacity and ductility, while the requirements in the serviceability limit state (SLS) were not fully satisfied due to geometric flaws in the connection modules. More experimental studies encompassing specimens with higher level of precision are therefore recommended to obtain enhanced performance in the serviceability limit state.