Investigations on bond performances of GFRP/stainless steel reinforcements using distributed fiber optical sensors (DFOSs)

Abstract

This study aims to examine the bond behaviors between concrete and glass fiber reinforced polymer (GFRP)/stainless steel bars. Distributed fiber optical sensors (DFOSs) are employed to investigate the tensile and bond behaviors in tension and bond tests. The mechanical properties of two different types of GFRP bars and one type of stainless steel bar are determined through tension tests, while the accuracy of the DFOSs is evaluated through comparison with reference methods such as strain gauge and extensometer. The bond tests aim to investigate the bond behaviors between concrete and the reinforcement bars, with a particular emphasis placed on a type of GFRP bars with a grey coating. Furthermore, the study compares the results obtained from DFOS in the bar groove and DFOS on the bar surface. In addition, the impact of various DFOS coatings and adhesives on the measured bar strains is investigated. The best combination of DFOS and adhesive is identified and applied to other bars to analyze the differences in strain distribution. Finally, the research concludes by presenting and analyzing the full strain distributions along the three different types of embedded bars. Overall, the research provides novel insights into the full bond behaviors between concrete and GFRP/stainless steel reinforcement bars and highlights the effectiveness of DFOSs in measuring strain during bond tests.