Experimental and numerical behaviour of hybrid R.C. columns under the effect of fire furnace

Purpose The purpose of this research is to study the effect of high temperature on concrete columns which are considered the most important part of the concrete structure. Glass fibres were used to study the effect of heat on them as well as on the properties of reinforcing steel and concrete. Design/methodology/approach High tensile stress may develop at the tension zone of the column section when the column is exposed to an axial compressive load with a relatively high eccentricity. Since fibre bars have a higher tensile strength than steel bars, they can be used in the tension zone of hybrid reinforced concrete columns to resist tensile stress, while steel bars can be used in the compression zone to resist compressive stress. However, as documented in prior research studies and advised by standards and codes, the mechanical qualities of concrete, steel and fibre bars are considerably damaged when hybrid columns are exposed to high temperatures. Findings When the fire temperature rises, the ultimate load value of the reinforced concrete column decreases. Also, steel bar reinforcing is more efficient than glass fibre bars in resisting high temperatures. The rate decrease in the strength of reinforced concrete columns to applied load on it decreases with the rise of the temperature to which the specimen was exposed during the burning period. Originality/value The experimental and numerical work includes a study of the effect of a fire furnace on the behaviour of hybrid R.C. columns. Three types of reinforcement were used steel bars only, G.F.R.P bars only and hybrid (steel and G.F.R.P) bars. These columns specimens were cast and divided into three groups according to the details of reinforcement, the effect of fire temperature and according to the eccentricity ratio. Two types of hybrid are used in this work. Fourteen R.C. columns were casted and divided into, 4 specimens not burn and 10 specimens burn at temperatures 300, 500 and 700.