International Concrete Abstracts Portal

"The American Concrete Institute sponsored an unprecedented six technical sessions on FRP Reinforcement for Concrete at the Vancouver Conference on March 28-31, 1993. Speakers and attendees were present from Europe, Japan, Canada and the United States. The papers in this Special Publication are organized in the same subject areas as the conference. The subject topic areas and symposium sections are: 1. FRP Material Properties and Testing Methods 2. FRP Reinforcement for Reinforced Concrete 3. FRP Reinforcement for Prestressed Concrete 4. Analysis And Design 5. The Japanese National Project for FRP Development 6. Applications of FRP Reinforcement The 55 technical papers in this report represent the most comprehensive compilation to date of FRP research, design, and application information. A comparison of the papers provides an insight to the approach to the use and development of FRP reinforcement within the research communities of Europe, Japan and North America. The two symposium volumes are also significant because substantial portions of the extensive Japanese national research project have been translated into English. The Japanese papers provide an insight to both the magnitude of the technical work being conducted in Japan and the organization of the Japanese research program." Note: The individual papers are also available as .pdf downloads.. Please click on the following link to view the papers available, or call 248.848.3800 to order. SP138

The authors introduced bends into FRP rods and, after embedding them in concrete, applied loads to investigate the tensile strength of the bent portions. The results show that the FRP rods ruptured at the bend, and that tensile strength decreases as the curvature of the bend increases. They also indicate that the tensile strength of the bend varies with the strength of concrete, fiber type, and method by which the rods are manufactured. 214-493

Fiber composites have become increasingly popular in the civil engineering community in recent years. The primary area of research and development of fiber composites in the concrete industry has been related to fiber reinforced plastic (FRP) reinforcing bars. Paper presents a different application of fiber composites in concrete structures, namely, confinement of concrete columns with fiber composite wraps for improved ductility and seismic performance. The confinement is accomplished by wrapping high-strength fiber composite belts around the columns. The belts are made very thin, resulting in flexibility sufficient to their being wrapped around circular as well as rectangular columns. The belts can be wrapped around the column in individual rings or in a continuous spiral. The ends of the belts can be mechanically coupled or they can be epoxy-bonded to the column. The confinement provided by the belts results in significant increase in the crushing strain of concrete well above that of unconfined concrete. This will improve the overall strength and ductility of the column. Paper presents the results of an analytical study and ongoing experimental study of concrete columns externally confined with fiber composite wraps.

Investigates the cracking control effectiveness for flexural cracking of carbon fiber net (CFN) reinforcement, a two-dimensional grid consisting of sets of continuous carbon fibers. Prestressed concrete sheet piles with and without CFN reinforcement were tested in bending and the crack widths were examined. The CFN used in these tests had an element spacing of 20 mm in each direction; each element consisted of three strands each of 18,000 (18K) filaments. The netting was located in the specimens at a concrete cover of 3 mm. Since CFN could be set near the concrete surface and the transverse strands of CFN play an important role in resisting the applied tensile force, the crack widths were controlled effectively. A model for the prediction of crack width in concrete reinforcement with CFN is proposed. Good agreement with the calculated results and the experimental data is obtained.

Presents the results of experimental study on the shock-absorbing performance of a prototype three-layered cushion system. This system consists of a concrete core slab reinforced with a braided aramid fiber plastic (AFRP) rod, and sandwiched between sand (top) and expanded polystyrol (bottom) layers. To study the effect of the rigidity, elongation, and bond strength of reinforcing bars on the shock-absorbing performance of a three-layered cushion system, three types of reinforcing bars were used: AFRP rod with surface bonded with silica, nonsand surfaced AFRP rod, and deformed steel bar. Furthermore, these results were compared with the results when a single sand layer was used as cushion material. The results achieved from these experiments are: (1) the transmitted stress of the three-layered cushion system is distributed more effectively than that of a single sand layer; (2) the distribution pattern of the transmitted stress in the three-layered cushion system was affected by the bond property of the reinforcing bar; and (3) duration time of the transmitted impact force was affected by the rigidity of the reinforcing bars.