224 / 2022-06-11 12:29:07

Development and Behavior of Novel FRP-UHPC Tubular Members

glass fiber reinforced plastic,uhpc

Ultra-high performance concrete (UHPC) have obtained increasing attention in research and industry communities. The unique merits of UHPC include extraordinary compressive strength and excellent corrosion resistance. However, UHPC under tension may exhibit a post-peak strain softening behavior. Although increasing fiber dosage could mitigate the strain softening behavior, using excessive fibers in UHPC for enhanced tensile properties may not be a good idea. Particularly, the issue of steel fiber corrosion is unavoidable if steel fibers are employed in UHPC.



Recently, fiber-reinforced polymer (FRP) grid or fiber textile has been proposed to be internal reinforcement for UHPC to solve the above issues. Our studies have also indicated that FRP grids have good bonding with the cementitious matrix with short fibers (Fig. 1). FRP grid also has an excellent tensile strength and satisfactory ultimate tensile strain owning to continuous fibers in FRP composites, making FRP-reinforced UHPC composite plates doomed to have excellent tensile properties. Also, FRP reinforcement could not only decrease the fiber dosage and cost of the UHPC, but also alleviate possible corrosion problem of the steel fibers in UHPC. If non-metallic fibers (e.g., polyethylene (PE) fibers) are used in FRP grid-reinforced UHPC composites, problems associated with corrosion are expected to be avoidable.



In this study, a series of novel forms of tubular members made of FRP grid-reinforced ultra- UHPC (referred to as “FRP-UHPC tubular members”) are developed. FRP-UHPC tubular members have excellent mechanical properties, and their excellent performances are demonstrated through three preliminary studies: i) behavior of FRP-UHPC plates and tubular beams (Figs. 2-3); ii) behavior of FRP-UHPC tubular columns under axial compression (Fig. 4); and iii) behavior of FRP-UHPC plates with a novel grouting sleeve connection system under bending (Fig. 5). The experimental programs and results are briefed in the abstract. The proposed FRP-UHPC tubular members are attractive in various structural applications such as pipelines, bridge box girders, permanent formwork of beams/columns, especially in marine environments (e.g. floating structures).