Mechanical behavior of concrete prisms reinforced with steel and GFRP bar systems

Abstract

Being immune to corrosion, and having a tensile strength up to three times higher than structural steel, glass fiber reinforced polymer (GFRP) bars are suitable for reinforcing concrete structures exposed to aggressive environmental conditions. However, a relatively low elasticity modulus of GFRP bars favors the occurrence of relatively large deformability of cracked reinforced concrete. Lack of ductility and degradation of properties under high temperature can be also identified as debilities of GFRP bars over steel ones. Combining GFRP and steel bars can be a suitable solution to overcoming these concerns. Nevertheless, the application of such reinforcement systems requires reliable material models. Unfortunately, the influence of the relative area of GFRP and steel bars on the tensile capacity of cracked concrete was never investigated from the experimental point of view, mainly crossing results from different tools on the assessment of the cracking process. This paper experimentally investigates deformations and cracking behavior of concrete prisms reinforced with different arrangements of steel and GFRP bars. The test results of 11 elements are reported. The cracking process is analyzed considering the hybrid reinforcement particularities and a preliminary approach is proposed for the prediction of the crack width for this type of reinforced concrete elements.

Parametric Design Studies of Mass-Related Global Warming Potential and Construction Costs of FRP-Reinforced Concrete Infrastructure

“…However, a lower GWP at construction and a possible longer service life can be motivations for choosing an FRP variant over a fully steel-reinforced variant. In addition to enhancing the durability, a hybrid option with two layers of main reinforcement (one FRP layer and one steel layer) also improves the tensile response of a structure, as the stiffness is higher compared to a pure FRP-reinforced structure, while the steel reinforcement can be exploited in the post-yielding stage [68]. However, it should be noted that in hybrid steel-CFRP structures, direct contact between the CFRP and steel reinforcement must be avoided, as it triggers accelerated galvanic corrosion [69].…”

Damage of bond in reinforced concrete: A detailed finite element analysis

“…1 Moreover, bond controls the effect of tension stiffening of the cracked RC elements. 2 Although the mechanics of bond behavior is quite well understood, still much needs to be done in quantifying various aspects of this highly complex phenomenon. 3,4 In the last decades, numerical simulation of bond action has emerged as a promising tool for bond analysis.…”

“…The bond ensures the composite action between reinforcement and concrete, controls the strength of the overlapped joints and beam‐column connections, limits the crack width, and guarantees the RC element's ductility under the ultimate loads 1 . Moreover, bond controls the effect of tension stiffening of the cracked RC elements 2 . Although the mechanics of bond behavior is quite well understood, still much needs to be done in quantifying various aspects of this highly complex phenomenon 3,4 …”

Factors influencing strength loss of glass‐fiber‐reinforced composite bars in highly alkaline environment of concrete

“…However, GFRP bars are an attractive alternative to traditional steel reinforcement of structural concrete exposed to highly corrosive environments, owing to their excellent resistance to electrochemical corrosion processes. 18,19,33,36,42 Some contrasting findings on the strength and stiffness characteristics of GFRP bars in the alkaline environment have been reported in the earlier studies. For example, Esmaeili et al 43 reported an inverse relationship between the strength loss and diameter of GFRP bars in contradiction to the findings of Arczewska, Polak, and Penlidis 44 and that of Benmokrane et al 45 Similarly, varied findings have been reported with regard to the reduction in elastic modulus of GFRP bars in the alkaline environment at elevated temperature.…”

“…This degradation is a major concern when GFRP is utilized as a reinforcement material in concrete. However, GFRP bars are an attractive alternative to traditional steel reinforcement of structural concrete exposed to highly corrosive environments, owing to their excellent resistance to electrochemical corrosion processes 18,19,33,36,42 . Some contrasting findings on the strength and stiffness characteristics of GFRP bars in the alkaline environment have been reported in the earlier studies.…”