Bond Strength of Standard and High-Modulus GFRP Bars in High-Strength Concrete

Abstract

The use of glass fiber–reinforced polymer (GFRP) bars in high-strength concrete (HSC) can solve durability problems associated with conventional steel reinforced concrete (such as premature deterioration due to corrosion) and increase the service life of structures. Experimental investigations were conducted to evaluate the bond characteristics of GFRP bars in HSC. Ninety six pullout specimens that had variable parameters, namely, bar diameter (15.9 mm and 19.1 mm), bar surface condition (sand coated), GFRP bar types (standard low modulus and high modulus), and embedded length (3, 5, 7, and 10 times bar diameter) were tested. The influence of each of these parameters is analyzed to understand interface bond between GFRP bar and HSC. Load-slip characteristics and failure modes of the pullout specimens are described. The performance of various codes in predicting bond stress of both low-modulus and high-modulus GFRP bars embedded in HSC is described based on experimental results.