Long-Term Flexural Behaviors of GFRP Reinforced Concrete Beams Exposed to Accelerated Aging Exposure Conditions

Yeonho Park,Young Kim,Swoo-Heon Lee

doi:10.3390/polym6061773

Yeonho Park, Young Kim + Show 1 more

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https://doi.org/10.3390/polym6061773

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Abstract

This study investigates the impact of accelerated aging conditions on the long-term flexural behavior and ductility of reinforced concrete (RC) members with glass fiber-reinforced polymer (GFRP) bars (RC-GFRP specimen) and steel bars (RC-steel specimen). A total of thirty six specimens were designed with different amounts of reinforcement with three types of reinforcing bars (i.e., helically wrapped GFRP, sand-coated surface GFRP and steel). Eighteen specimens were subjected to sustained loads and accelerated aging conditions (i.e., 47 °C and 80% relative humidity) in a chamber. The flexural behavior of specimens under 300-day exposure was compared to that of the companion specimens without experiencing accelerated aging conditions. Results indicate that the accelerated aging conditions reduced flexural capacity in not only RC-steel, but also RC-GFRP specimens, with different rates of reduction. Different types of GFRP reinforcement exhibited different rates of degradation of the flexural capacity when embedded in concrete under the same exposure conditions. Several existing models were compared with experimental results for predicting the deflection and deformability index for specimens. Bischoff and Gross’s model exhibited an excellent prediction of the time-dependent deflections. Except for the deformability index proposed by Jaeger, there was no general trend related to the aging duration. This study recommends the need for further investigation on the prediction of the deformability index.

Highlights

The corrosion of steel reinforcement in concrete is a major deterioration mechanism, leading to degradation in the strength and stiffness of reinforced concrete structures
This study presents the flexural behaviors and ductility of concrete beams reinforced with glass fiber-reinforced polymer (GFRP)
Flexural GFRP reinforcement in the concrete led to a significant improvement in the flexural strength

Summary

Introduction

The corrosion of steel reinforcement in concrete is a major deterioration mechanism, leading to degradation in the strength and stiffness of reinforced concrete structures. The reduction in the useful service-life of steel-reinforced concrete structures is a cause of concern to the construction industry, mainly due to reinforcement corrosion [1]. To reduce costs for repairing significantly corroded structures, in recent years, non-metallic materials of fiber-reinforced polymer (FRP) are increasingly being used as an alternative to steel reinforcement. The growing application of FRP reinforcement is a result of its resistance to corrosion and high strength-to-weight ratio when compared to conventional steel reinforcement [2]. Hybrid carbon-glass FRP sheets have been used [5]. This study focuses on glass-FRP (GFRP) reinforcement as a construction material.

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