Effect of Fire on Carrying Capacity of Concrete Columns Confinement with Multi-Layers of CFRP

Abstract

FRP reinforced polymers are widely accepted for use in civil engineering applications to strengthen constructions and application of confinement on the concrete columns, thereby increasing their ductility and increasing their carrying capacity as these materials are characterized by high tensile strength, high strength-to-weight ratio and high corrosion resistance of FRP composites, etc. In addition, the exposure of reinforced concrete structures to fire is one of the most dangers challenges that lead to great destruction and failure the structural in addition to loss of life. With the development of computer simulation theories to study the behavior of elements and structures under the influence of different loads (static, dynamic, thermal, etc.), it is possible to study the behavior of concrete columns under the influence of axial vertical and non-axial structural loads, and compare the results with previous research, thus saving time, effort and cost instead Of laboratory testing. Strengthening concrete columns with fiber-reinforced polymers (FRP) has been studied extensively, but the majority of published studies have focused on circular columns. Most concrete columns in the field have square or rectangular cross sections and resist eccentric loading as well. The objective of this study is to investigate the performance of square reinforced concrete (RC) columns, wrapped with carbon FRP subjected to fire so, in this paper, an analytical study was conducted using the ANSYS Workbench program, which follows the finite element method, to determine the effect of layers number of CFRP on carrying capacity of concrete columns and to know the effect of external standard fire on confined concrete columns with  CFRP. The numerical results were compared with experimental results as far as possible, and revealed the accuracy of the analytical models, when compared to the experimental studies. The results shown that with increase the layer number of CFRP, the carrying capacity of concrete columns will increase,   no benefit with increase the number of CFRP more than 4 layers where polymers materials are sensitive to fire so that it needs to insulation.

Keywords: confinement, CFRP, External fire, ANSYS Workbench.

DOI: 10.7176/CER/12-12-01

Publication date: December 31^st 2020