JEC COMPOSITES MAGAZINE - Issue #33 - June 2007 - 47

ver 156,000 bridges out of the 595,000 included in the 2005 USA National Bridge Inventory (Federal Highway Administration, 2005) do not meet standard safety requirements. In particular, 76,000 bridges are classified as “structurally deficient” and are in need of rehabilitation or, in the worst cases, replacement. Corrosion of the steel reinforcement in concrete decks and safety appurtenances is by far the major instrument of degradation, accruing from the routine use of de-icing salts on roads and exposure to harsh environments. Higher traffic demands and load requirements further emphasize the need to upgrade the USA transportation infrastructure. O Rapid bridge deck construction with FRP reinforcing grids GRIDFORM® – FRP deck reinforcement solution STRONGWELL CORPORATION FABIO MATTA, GRADUATE STUDENT, CENTRE FOR INFRASTRUCTURE ENGINEERING STUDIES, UNIVERSITY OF MISSOURI-ROLLA CORPORATE MARKETING MANAGER, Bridge owners need solutions to rapidly replace bridge decks and safety railings in order to avoid costly road closures and traffic disruptions normally associated with traditional steel reinforced concrete bridge deck construction. Prefabricated stay-inplace FRP reinforcing panels that take advantage of advanced composites’ versatility, lightweight, and corrosion resistance make the construction of durable bridge decks faster, safer, and very competitive. GLENN BAREFOOT, Application • two-part vertical connectors that space the grating layers 100 mm apart. The panels are typically fabricated 2.5 m long and to the width of the bridge deck to be constructed. The I-bars are the main load-carrying elements and their shape and spacing are designed to make walking over the panels easy and safe. The cross-rods provide shrinkage and temperature reinforcement and constrain the core concrete to ensure load transfer into the I-bars. Stay-inplace (SIP) form plates are epoxy-bonded onto the outer face of the bottom-layer I-bars. The panels weigh a little less than 24 kg/m2 (figure 1). Fig. 1: Close-up of prefabricated FRP SIP deck reinforcement panel. In 2001, Dr Lawrence Bank, a civil engineering professor at the University of Wisconsin-Madison, began working with Strongwell Corporation to create very large FRP prefabricated panels for the internal reinforcement of concrete bridge decks using pultruded grating components. The two-layer reinforcing grid panels are prefabricated by assembling three off-the-shelf pultruded glass/vinyl ester profiles, which are normally used in grating applications for corrosive environments. The components are: • I-bars (38 mm) running continuously in the direction perpendicular to traffic; • three-part cross-rods running through pre-drilled holes spaced at 100 mm on-centre in the I-bars web in the direction parallel to traffic; The structural effectiveness of pultruded FRP reinforcing grids as internal reinforcement of concrete decks has been proved through extensive research during the last 14 years. The firstgeneration GRIDFORM® panel system was installed on a Waupun, Wisconsin bridge in 2003 and a second project was No33 June 2007 / JEC Composites Magazine

JEC COMPOSITES MAGAZINE - Issue #33 - June 2007

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #33 - June 2007