Bond performance of small-diameter GFRP Bars in concrete

A comprehensive comprehension of the bond behavior between Fiber-Reinforced Polymer (FRP)bars and concrete structures is essential for the successful reinforcement of concrete structures using FRPbars. This understanding is necessary to ensure adequate force transfer and effective control of cracks. Onthe other hand, practical implementation of design standards for FRP bars can present challenges, as theyoften require extremely long development lengths. This issue arises from the assumption of uniform bondstress, making it difficult to achieve in real-world scenarios. Therefore, this study presents an experimentalinvestigation conducted to assess the bond behavior of glass fiber-reinforced polymer (GFRP) bars usingpullout test. The bond strength of four pullout test specimens were conducted to investigate the effect ofembedment length of small-diameter (i.e., ۸ mm) GFRP bars in concrete. The theoretical developmentlength was computed using the equations of ACI and CSA standards. The specimens with an embedmentlength of ۱۵db failed due to the rupture of GFRP bars. Test results demonstrated that the design standardsoverestimate the development length of GFRP bars. Hence, test results indicated that the prediction ofdesign standards could result in significant differences in the development length of small-diameter GFRPbars in concrete.

کلیدواژه ها:

GFRP bar ، Pullout test ، Development length ، Bond strength.