Durability of GFRP Reinforced Concrete in Field Structures

Abstract

Synopsis: Recently, ISIS Canada studied the durability of GFRP in concrete in several field structures across Canada. The objective of the study was to provide the engineering community with the results of the performance of GFRP materials that have been exposed to the concrete environment in built structures. Cores of GFRP-reinforced concrete were removed from five field structures. Analytical methods, namely optical microscopy, scanning electron microscopy and energy dispersive x-ray, differential scanning calorimetry and infrared spectroscopy, were used to determine the composition of GFRP after being subjected to the alkaline environment of concrete for five to eight years. Three research teams from four Canadian universities performed microanalyses of the GFRP and surrounding concrete independently. Results indicate that no deterioration of GFRP took place in any of the field structures. No chemical degradation processes occurred within the GFRP due to the alkalinity of the concrete. The overall conclusion of the study is that GFRP is durable in concrete. Also, it was concluded that the CHBDC was conservative in its first edition by not permitting GFRP as primary reinforcement. As a result of the study, the second edition of the CHBDC, currently in the final stages of approval, permits the use of GFRP as primary reinforcement.