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This paper describes research on the evolution of a cost-effective, structural stay-in-place (SIP) formwork bridge deck system with an integrated modular three-dimensional fiber-reinforced polymer (FRP) reinforcement cage. Recent research conducted at the University of Wisconsin is reviewed to show the evolution of the reinforcing system to include an integral FRP SIP form. The evolution occurred through laboratory testing, which was followed by the design and construction of two bridge structures owned by the State of Wisconsin. Each structure used different FRP reinforcement and formwork. These projects pointed out the need for a competitive SIP formwork to be used in conjunction with FRP reinforcement. Two specimens with different FRP reinforcement and SIP formwork arrangements were tested. Full-scale deck slab specimens were tested by applying a simulated wheel design load to investigate the static response, ultimate capacity, and failure mechanism. The most economical FRP reinforcing system has been implemented in a superstructure replacement project in Greene County, Missouri.

A description is given of laboratory testing, initial test results, and continuing research to develop design procedures and plans for construction of a two-span highway overpass on US-151 in the state of Wisconsin using only a fiber-reinforced polymer (FRP) reinforcement system in the concrete bridge deck. The use of FRP reinforcing is being pursued to increase the durability of bridge decks and to reduce unit cost and time. The unique aspect of the new bridge is that it will use FRP stay-in-place formwork, placed over precast concrete I girders, to serve as formwork and as the bottom transverse reinforcement of the bridge deck. In addition, a heavy-duty prefabricated FRP grid will be used for the top layer of concrete reinforcing. Full-scale prototype laboratory testing is being used to develop design recommendations including effective distribution widths. From the spring to fall of 2003, a construction productivity study comparing the FRP deck construction sequence with that of identical adjacent steel reinforced deck will be conducted. Both bridges will be field load tested before opening to traffic. The FHWA Innovative Bridge Research and Construction Program is supporting the research and construction.

A model specification for fiber-reinforced polymer (FRP) composite materials for use in civil engineering structural systems was developed. The model specification provides a classification system for FRP materials, describes admissible constituent materials, and specifies limits on selected constituent volumes. The specification provides procedures for qualifying FRP composite laminates and for accepting FRP composite parts constructed of qualified laminates. Test methods to obtain mechanical and physical properties were devised, along with stipulation of limiting values for selected properties for both laminates and parts. Based on the Arrhenius model, a protocol was outlined for predicting long-term property values subjected to accelerated aging.

The experimental and simulated response of steel W-beam guards to pendulum impact loading for impact velocities of 20 km/h, 30 km/h, and 35 km/h are presented. The guardrails were supported by four posts and cable-anchored at each end to ensure that the full tension capacity of the rail could be developed. Experiments carried out with a 912-kg impact pendulum are compared with LS-DYNA finite-element simulations of the impact events. Pendulum tests were completed at the Turner Fairbank Highway Research Center of the Federal Highway Administration. Acceleration, velocity, and displacement time histories are compared for the pendulum impact test and the LS-DYNA simulations. Comparison of the experimental and simulation acceleration records is made using the Numerical Analysis of Roadside Design time-domain statistics. The comparative statistics show that the simulations are in good agreement with the experiments. Guardrail tension data and cable tension data are presented from the LS-DYNA simulations. Results show that the guardrail was close to its tension yield point when impacted an initial velocity of 35 km/h.