Assistant professor, Faculty of Engineering, Zagazig University, Zagazig, Sharkia,
This paper presents an experimental investigation on the effect of cooling methods and means of fire extinguishing on the mechanical properties of steel bars used in reinforced concrete if subjected to a heat source. By simulating the heating effect of possible fire on the steel bars, an experimental plan has been made to include cases in which the bars may pass metallurgical phase transformation. Results indicate that the cooling of steel bars by means of water largely affects the mechanical properties especially if specimen temperatures are greater than the critical temperature compared with other cooling techniques, which are air or sand. The usual practice of extinguishing fire and cooling steel bars with water should be reconsidered as it increases the bars' hardness and ultimate tensile strength at the expense of reducing ductility. This makes the steel bars' properties less than the desired mechanical properties in building construction.
Paper ID: JTE10771J