Testing of a complete bridge at scale with FRP stay-in-place structural forms for concrete deck failing in punching shear

Fibre Reinforced Polymer (FRP) Stay-in-Place (SIP) formwork has received increasing attention recently as a system for constructing concrete bridge decks, particularly in slab on girder bridges. The system offers the potential for faster construction and improved durability for bridge decks. While the system has been investigated experimentally and seen some field application, there is an absence of test data regarding the ultimate limit state performance of FRP SIP formwork decks in the context of an actual bridge. Testing is most often conducted on bridge deck sections with free edges which provides a conservative but inaccurate estimate of the actual bridge deck's capacity. This phenomenon was investigated by comparing the test results of four bridge deck tests including once bridge deck section and three deck panels within a full bridge. The testing was conducted at 1:2.75 scale. Testing of a bridge deck section revealed a 20% drop in capacity when compared to a panel in a full bridge of identical design. The deck section also exhibited a 23% lower post cracking stiffness (in terms of centreline deflection). Comparison of two bridge panels with different spans revealed span to effect on stiffness but a negligible impact on punching shear capacity. Several failure criterion were evaluated against the test results to assess their efficacy in predicting punching shear capacity. Three code equations (AASHTO, CSA A23.3 and CSA S6-06) as well as a failure criterion proposed in the literature were found to be conservative in predicting the capacity of the FRP SIP formwork decks in question.