Presents the test results on fundamental mechanical properties of several kinds of continuous fiber bars. Three kinds of fiber materials (carbon, glass, and aramid) have been used. The shape of the deformed bars differed and the diameter was approximately constant (8 mm). Tensile strength, Young's modulus, tensile creep, and pullout bond strength were tested. The main results were that Young's modulus of carbon fiber bars is about two-thirds that of Young's modulus of steel bars, whereas that of glass fiber bars and aramid fiber bars are nearly one-third that of steel bars; also, the initial slip bond stress and maximum bond stress were more likely to differ with the shape of the continuous fiber bars than with the kinds of fiber materials.

Aramid FRP rods, a composite of reinforced aramid fibers, are corrosion-free and used in various fields. Aramid FRP rods have been gaining attention for their use in prestressed concrete tendons. They have high tensile strength and excellent resistance. They are manufactured from aramid fibers and vinylester resin using a pultrusion process. The physical properties of aramid FRP rods were determined experimentally. Use of aramid FRP rods as prestressed concrete tendons requires a high-bond performance with grout or concrete, and a special anchoring system also had to be developed. Studies carried out in response to these requirements enabled the authors to conclude that aramid rods could make viable prestressed concrete tendons. A pretensioned road bridge (L = 12.5 m), a post-tensioned road bridge (L = 25.0 m); a ground anchor, and a prestressed concrete berth were constructed using aramid FRP rods.

Lateral confinement of concrete members by means of spirally wrapping fiber-reinforced-plastic (FRP) composites onto the concrete surface may increase compressive strength and ultimate strain (pseudo-ductility). It may also provide a mechanism for shear resistance, and inhibit longitudinal steel reinforcement buckling. Lateral confinement of concrete members as a strengthening/repair technology is expected to have an impact in the rehabilitation/renovation of buildings and infrastructure. Structures that have been damaged, or need to comply with new code requirements, or are subjected to more severe usage are the primary targets. In this project, an experimental and analytical study of concrete strengthened with FRP lateral confinement I conducted using compression cylinders (300 and 600 mm in length) and l/4 scale column-type specimens. The latter specimens have a circular cross section and given longitudinal/transverse steel reinforcement characteristics. Column-type specimens are subjected to cyclic flexure with and without axial compression. When an aramid FRP tape is used as the lateral reinforcement, the variables are tape area and spiral pitch. In the case of filament winding with glass fiber, the thickness of the FRP shell is varied. The limited experimental results obtained at this stage of the research program indicate that lateral confinement significantly increases compressive strength and pseudoductility under uniaxial compression.

The use of fiber reinforced plastic reinforcement in reinforced and prestressed concrete structures is gaining increased attention. This paper describes the results of a preliminary experimental program in which strands made of carbon fiber composites (trade name CFCC - Carbon Fiber Composite Cable) were used as pretensioning reinforcement in two partially prestressed concrete T beams. The beams were ten foot in length and 12 inches in depth and contained, in addition to the carbon fiber strands, conventional reinforcing bars Experience gained with the stressing, anchoring, and releasing of CFCC strands is described. Relevant test results regarding load-deflection response, curvature, stress-increase in the reinforcement with increased load, cracking and crack widths, and failure modes are reported, and compared to results obtained from similar tests using prestressing steel strands. The load deflection response of beams prestressed with CFCC strands showed generally a trilinear ascending branch with decreasing slope up to maximum load. Deflections and crack widths were generally small but increased rapidly upon yielding of the non-prestressed steel reinforcement. The post-peak response was characterized by rapid step-wise decrease in load due to successive failures of the CFCC strands, and stabilization at about the load-carrying capacity of the remaining steel reinforcing bars. The presence of reinforcing bars helped the beams sustain large deflections before crushing of the concrete in the compression zone. Analytical predictions of the load-deflection response using a nonlinear analysis method were used and led to reasonable agreement with experimental results.

The three-dimensional fabric studied as reinforcement for concrete is a stereo-fabric made of fiber rovings, woven into three directions, and impregnated with epoxy resin. Fiber material, number of filaments, and distance between rovings can be varied easily. Efficient production is also possible, since three-dimensional weaving, resin impregnation, and hardening can all be done by an automatic weaving machine. The authors investigated the flexural and fire-resistance behaviors of three-dimensional fabric reinforced concrete (3D-FRC) toward applying the material to building panels. The fibers studied were carbon and aramid, and the matrix was vinylon short-fiber reinforced concrete. The results demonstrate that 3D-FRC panels have sufficient strength and rigidity to withstand design wind loads, and the fire resistance of 60 min was achieved. The 3D-FRC panels have been used for curtain walls, parapets, partition walls, louvers, etc., and installations amount to 7000 m 2.