This CD-ROM consists of 11 papers which were presented in two special sessions sponsored by ACI Committee 440 at the ACI Spring Convention in Los Angeles, California, on March 31, 2008. The technical papers presented at the sessions and published in this volume cover both open and closed FRP forms, including bridge decks, concrete-filled tubes, and girders, and address important relevant aspects such as surface preparation, bond aspects, fatigue, constructability, confinement, and field applications.

Octaform(TM) system is a stay-in-place concrete forming system that consists of interconnected PVC polymer-based elements. These elements are assembled on the construction site to form a hollow wall shell structure, which is then filled with concrete to complete the wall. This paper reports on the flexural behavior of these specimens. Eight of the tested specimens were fabricated using the Octaform system and the remaining four acted as control specimens (without forming system). All specimens were 305 mm (12 in.) wide and 2.5 m (8.25 ft) long. The specimens were reinforced with two 10M bars. The variables studied were the depth of the specimen (150 mm [6 in.]) or 200 mm [7.87 in.]) and the connector configuration. Two types of connectors were used: flat in the middle or inclined (45o) at the corner. The specimens were monotonically tested in horizontal position (to simulate flexural behavior) in four -point bending. Test results showed that the Octaform system increased the cracking load, yield load. And ultimate load by 36%, 78% and 36% on average, respectively, compared to the control specimens. Also, the ductility index for specimens encased with Octaform increased by 25%. The type of the connectors had no effect on the general behavior of the Octaform-encased specimens. A simple limit state model was proposed to predict the flexural capacity of the Octaform-encased specimens. In general, the predicted values compared well with the experimental values.

This paper presents the development of a steel-free concrete bridge deck reinforced with carbon fiber-reinforced polymer (CFRP) stay-in-place (SIP) form. The SIP form has a configuration of a flat laminated CFRP plate stiffened with rectangular stand-ups filled with nonstructural foam and interlocking ribs at the interface. Thin layers of CFRP mesh are used for top tensile reinforcement at intermediate continuity regions. Performance evaluation of short-term static flexure was conducted through tests on a series of 610 mm (2 ft) wide deck specimens. Dynamic response of the system (for example, natural frequencies and mode shapes) was characterized using a forced vibration testing method. Furthermore, long-term behavior under fatigue simulating traffic loads was experimentally assessed using a full-scale continuously spanned specimen. The observations from these laboratory tests on load-carrying capacity and failure modes showed a satisfactory and efficient design of the system. These test results were further used to calibrate a finite-element based nonlinear model (ABAQUS) for numerical simulation and development of a simplified design procedure. Environmental effects due to temperature, creep, and shrinkage were considered using the calibrated numerical model, the results of which showed insignificant residual stress caused by these effects between concrete and CFRP composites over time.

An investigation of a structural fiber-reinforced polymer (FRP) stay-in-place (SIP) form used to construct and reinforce a deck for a prototype military bridge system is discussed. The FRP SIP form is supported by a deployable truss and the bridge is completed with a cast-in-place deck. A unique feature is that the fiber-reinforced concrete deck also acts as the upper chord of a truss for the bridge-subjecting it to combined bending and longitudinal axial load. An experimental program investigated the behavior and capacity of the fiber-reinforced concrete deck. Specimens spanning 1.83 m (6.00 ft) with simple supports and 3.66 m (12.0 ft) with an intermediate support were tested. The results were statistically analyzed and compared to the ACI 440.1R design guide. The results showed that flexural and flexural-shear capacities were accurately predicted, provided that the eccentricity, due to the combined loads, was accounted for in the calculations.

The State of Wisconsin recently constructed a highway bridge as part of the FHWA Innovative Bridge Research and Deployment Program. The superstructure is composed of precast concrete I-girders acting compositely with the concrete bridge deck that uses a fiber-reinforced polymer stay-in-place (FRP-SIP) formwork system that serves as positive flexural reinforcement. In-place load test strain data are used to compute wheel load distribution widths and estimates for bending moments acting on unit widths of bridge deck. These widths are compared with those computed using the AASHTO-LRFD and AASHTO Standard specifications. The in-place field data indicate that bending moments within the deck system are reasonably close to predictions made using the Standard and LRFD specification bridge deck approximate analysis procedures. The Standard specification estimates for bending moment per unit width of bridge deck were found to be conservative for interior and exterior deck spans. The LRFD specification estimates for strip width resisting wheel loads are also conservative for interior and exterior deck spans when compared to field-measurement-based predictions.