The extrinsic influence of carbon fibre reinforced plastic laminates to strengthen steel structures

Abstract

The intrinsic advantages of strengthening the steel-based structures by the use of fibre reinforced plastic (FRP) material have not yet been fully exploited. In this paper, a succinct overview of recent studies made to enhance the strength of steel beams using FRP laminates is presented. The results presented and discussed in this paper were obtained by closely studying the behaviour of steel beams strengthened with carbon FRP material. An attempt is made to succinctly summarise the findings for two different types of strengthening of the steel beams using carbon FRP laminates. The first type of beams focuses on enhancing the strength of steel in flexure while the second focuses on increasing the shear strength of the beams. Three beams were designed so as to cause them to fail in flexure. Of the beams studied, two were strengthened using carbon FRP strips attached to the tension flange. One of the beams was tested to facilitate comparison of their behaviour to the two beams which are strengthened in flexure. Three other beams were designed such that they failed predominantly in shear. Of these three, two were strengthened with carbon FRP strips attached to the webs while the third beam was used as a control beam for the purpose of drawing comparisons. Preliminary results revealed a noticeable increase in the strength for both the flexure strengthened beams and the beams strengthened in shear. The observed increase in shear strength of the beams was 26% while the increase in strength for the beams tested in flexure was 15%. This study convincingly shows that it is possible to strengthen steel beams using carbon FRP laminates in both flexure and in shear.

Rehabilitation of Steel I-Beam with Basalt Fiber Reinforced Polymer

“…In other research, Selvaraj and Madhavan (2017) investigated C channel steel beams rehabilitated with CFRP sheet and found an improvement in failure modes (from lateral torsional buckling to yielding) and flexural moment capacity of the beams. Patnaik et al, (2008) studied flexural and shear strengthening of steel girders with CFRP plates. They showed that by using CFRP plates attached to the web of the girders, shear strength of the steel girders could be increased.…”

Effectiveness of Shear and Flexural Repair and Strengthening of Box section Steel Beams using CFRP Laminates

“…Some researchers have demonstrated different techniques for strengthening of steel webs subjected to shear by CFRP. Patnaik et al (2008) [11] has published results of an analytical and experimental program focused on shear strengthening of steel built-up I-beams. In this research three steel beams were designed to fail in shear.…”

Numerical Study of Strengthened Slender I‐girders With Fiber Reinforced Polymers

“…Most scientific research on the topic of FRP reinforcements and adhesives have been developed in the last five years. In most cases, carbon fibers were applied in the composition of FRP reinforcement [4][5][6][7][8][9][10], while some studies considered glass fibers [4,5,[10][11][12][13] or basalt fibers [14]. Furthermore, the FRP material as reinforcement was applied in different manners, as profiled shape ( Fig.…”

“…b) Ordered fibers and in situ application of the polymer matrix[8].c) FRP fabrics[6]. d) FRP laminated strips[10].| Reinforcement by stiffening the web surface using FRP and structural adhesives…”