FRP-Reinforced/Strengthened Concrete: State-of-the-Art Review on Durability and Mechanical Effects

Abstract

Fiber-reinforced polymer (FRP) composites have gained increasing recognition and application in the field of civil engineering in recent decades due to their notable mechanical properties and chemical resistance. However, FRP composites may also be affected by harsh environmental conditions (e.g., water, alkaline solutions, saline solutions, elevated temperature) and exhibit mechanical phenomena (e.g., creep rupture, fatigue, shrinkage) that could affect the performance of the FRP reinforced/strengthened concrete (FRP-RSC) elements. This paper presents the current state-of-the-art on the key environmental and mechanical conditions affecting the durability and mechanical properties of the main FRP composites used in reinforced concrete (RC) structures (i.e., Glass/vinyl-ester FRP bars and Carbon/epoxy FRP fabrics for internal and external application, respectively). The most likely sources and their effects on the physical/mechanical properties of FRP composites are highlighted herein. In general, no more than 20% tensile strength was reported in the literature for the different exposures without combined effects. Additionally, some provisions for the serviceability design of FRP-RSC elements (e.g., environmental factors, creep reduction factor) are examined and commented upon to understand the implications of the durability and mechanical properties. Furthermore, the differences in serviceability criteria for FRP and steel RC elements are highlighted. Through familiarity with their behavior and effects on enhancing the long-term performance of RSC elements, it is expected that the results of this study will help in the proper use of FRP materials for concrete structures.

Experimental Behavior of High-Strength Concrete Reinforced with Aramid Fiber and Polyurethane Resin

“…The study emphasizes the need for proper understanding of these factors to ensure the effective use of FRP materials in concrete structures and discusses serviceability criteria for FRP-reinforced concrete elements. Overall, the findings contribute to enhancing the long-term performance of RC elements using FRP materials [31]. Imjai et al introduced a new macro-mechanical model to accurately calculate the bend capacity of bent fiber-reinforced polymer (FRP) bars in reinforced concrete elements.…”

“…Addition of AF in concrete mixes gradually reduces the workability properties, but addition of PR in optimized AF enhances the slump value of HSC mixes made with optimum dosages of AF (Figure 3). It is concluded that the production of HSC is possible with the addition of AF without compromising the workability properties of concrete, thereby adding the PR [29][30][31][32].…”

Damage Detection in FRP-Reinforced Concrete Elements

“…The literature on the application of non-destructive testing (NDT) methods for the internal application of FRP is limited and scarce. There is no standard guide available for the inspection of FRP-RC elements [ 24 , 25 , 26 ]. This represents a knowledge gap that this research study attempts to address.…”

Experimental and numerical investigations of masonry ‎ beams performance under bending loads

“…Additionally, CFRP bars possess outstanding structural properties such as high tensile strength, a high strength-toweight ratio, and non-corrosive, non-magnetic attributes. The strength-to-weight ratio of CFRP bars is 10-15 times higher than that of steel bars [1][2][3][4][5][6][7][8][9][10]. Using non-corrosive FRP (fiber-reinforced polymer) bars in such constructions has proven advantageous in overcoming the issue of steel corrosion and effectively enhancing durability [11].…”