Predictive model for slenderness limit of circular RC columns confined with FRP wraps

Abstract

Application of fiber-reinforced polymer (FRP) for retrofitting and rehabilitation of concrete structures is a common method. The main role of FRP confinement for reinforced concrete (RC) columns is to increase the ultimate strength and strain of confined concrete core and therefore improve in the load carrying capacity of the columns. However, it is possible that a previously short column fails due to buckling after the application of FRP confinement. In other words, the enhanced compressive strength of a retrofitted column may go beyond its buckling load. Therefore, a design criterion to predict this condition is necessary for the designers in the preliminary and final stages of the design. In this paper, a predictive model is proposed to determine the slenderness limit of FRPconfined circular RC columns. The suggested relation was derived using one of the accurate design-oriented strength models for FRP-confined concrete columns as well as analytically derived buckling equations. The effect of hybrid FRP confinement is also incorporated in the suggested slenderness limit. Moreover, a parametric study was performed on the suggested model to specify most influential parameters. The accuracy of the proposed relation was evaluated using a database of experimental results collected from previous studies. The results of the evaluations demonstrated acceptable accuracy of the proposed relation in predicting behavior and failure mode of FRP-confined RC columns.

Analysis of a compressive strength model for FRP‐confined damaged concrete columns based on the Drucker–Prager yield criterion

“…Numerous studies have shown that fiber reinforced polymer (FRP), such as aramid fiber reinforced polymer (AFRP), basalt fiber reinforced polymer (BFRP), carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP), can significantly improve the load bearing and deformation capacity of damaged/undamaged concrete structures 1–8 . To accurately predict the load bearing capacity of damaged concrete after FRP strengthening, many compressive strength models have been proposed 9–18 .…”

Failure analysis of hybrid strengthened RC square column

“…In developing fibre-reinforced plastics (FRP) materials, different FRP techniques have been developed and used because of their distinct properties, such as high tensile capacity, high strength-to-weight ratio, and easy handling; however, FRP also has some disadvantages, such as inappropriate use in fire environments, wet surfaces, and inadequate bonding with concrete surfaces. Additional treatment is required to counter these environments [7][8][9][10][11].…”