PERFORMANCE OF THERMOPLASTIC FIBER REINFORCED POLYMER REBARS

摘要

Extensive efforts are being directed to application and development of FRP products in civil engineering structures, including the use of FRP rods as reinforcement for concrete. A new technology has been introduced for production of FRP utilizing a thermoplastic polymer matrix. An advantage of thermoplastic polymer resins is their ability to be formed after initial manufacturing of a straight profile similar to traditional steel rebar. Thermoset resins cannot be bent after the product is cured; bends must be made during initial production. Thermoplastics are in general tougher, more impact resistant, and more ductile than thermosets. An experimental program was carried out to investigate the mechanical properties of the thermoplastic composite rods and to optimize the product for use as a replacement of steel in reinforced concrete applications. In this endeavor, achieving an acceptable bond between concrete and FRP rods was critical. Several series of tests were conducted using various mechanical, geometrical, and surface treatment parameters to optimize the surface and cross-sectional shapes. To this end, the test program consisted of tensile strength and modulus of elasticity tests and bond to concrete tests. Development of the optimum rebar product is completed. In addition, a new test procedure was developed to address concerns about long-term bond performance of the rods with new material. A series of bond-creep tests were completed.