Behavior of hybrid R.C. columns under the effect of fire furnace (experimental and numerical study)

ABSTRACT

When fire exposes the hybrid reinforced concrete R.C. columns, it seriously damages the mechanical qualities of steel bars, concrete, and glass fiber reinforced polymer G.F.R.P. bars. This study focused on hybrid reinforced concrete R.C. columns’ behaviour and failure modes that were eccentrically and concentrically loaded during the fire until a failure. The behaviour of these R.C. columns will be quantified by demonstrating and going over the load-displacement relationships, failure mechanisms, crack patterns, strain distribution at failure, ductility, and stiffness. The number and width of cracks in the columns heated to 300 ºC, 500 ºC, and 700 ºC were significantly more than in the unheated columns. When the specimen is exposed to high temperatures, less force is needed to cause a first crack, and the ultimate strength decreases as the applied load and eccentricity ratio values increase. Hence, all specimens’ axial and lateral displacement values increase. This can be explained by two factors: the depth of the practical section because of the thermal expansion effect and the cracking expansion of concrete when subjected to high temperatures, and heating causes a loss in stiffness of column because the elasticity of concrete’s modulus of elasticity drops.

KEYWORDS:

• Hybrid R.C. columns
• electrical furnace
• materials properties
• experimental work
• test the specimens
• numerical study

Acknowledgments

The authors would like to express deep thank for the technical assistance of the laboratory staff at the College of Engineering- University of Al-Qadisiyah.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Authors’ contributions

Ali Kadhim Sallal: he cast the specimens, tested them, and wrote the research

Haitham Ali AL-Thairy: he supervised the process of auditing the results of specimens testing

Seyed Alireza Zareei: he supervised the process of analysing data, and comparing the results with each other

Niloofar Salemi: she supervised the process of writing the thesis

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article [and/or] its supplementary materials.

Ethical approval

This article doesn’t contain any studies with human participation or animals performed by any of the authors.

Additional information

Funding

No funding was received for this project.