Abstract: Composite column systems have become popular in tall building construction due to combining the rigidity and formability of reinforced concrete with the strength, ductility, and speed of construction of structural steel to produce an economic structure. This paper presents an experimental study to get more knowledge about the characteristics and the fire resistance of encased composite concrete columns. Three-scale three reinforced composite concrete columns were constructed and tested up to failure under direct fire at 500◦C for two hours. The experimental program Consists of three specimens with 150 mm in diameter and 1500 mm in height, the first specimen (CIG 500 ͦc) reinforced by steel bars and built-up section have 7 gaps with a diameter of 5cm at the section web, the second specimen (CIB 500 ͦc) reinforced by steel bars and built-up section have 56 bolts and finally, the third specimen (CIP 500 ͦc) reinforced by steel bars and built-up section has 14 welded metal plate. The performance of the tested composite columns specimens is evaluated based on the crack pattern, first crack, failure load, ductility. Moreover, the experimental results are shown a proportional relationship between the degree of temperature and residual strength, causing the residual strength to decrease by 18.29 %. The result shows that the failure load for the encased composite column by plates (CIP 500 ͦ c column) was much greater than the load-carrying capacity of other composite columns, this is due to the high capacity of steel material which is found inside the column. After exposure to a degree of fire 500 ◦ C, the encased composite column by plates steel shows that the failure load is higher than the failure load for the encased composite column by gaps and bolts by 29.7% and 8.17% respectively.
Keywords: encased composite; concrete columns; fire exposure; civil engineering.
Title: Behavior of Encased Composite Concrete Columns under Fire Exposure
Author: Mohammed E. Elghobary, Ahmed Bakhit, Fouad Khairallah, Hala Mamdouh
International Journal of Civil and Structural Engineering Research
ISSN 2348-7607 (Online)
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