EFFECTS OF HEAT ON THE PROPERTIES OF STEEL REINFORCEMENT IN REINFORCED CONCRETE STRUCTURES

ABSTRACT

With the increased incidents of major fires in buildings and concrete being subjected to elevated temperature, a critical study on the effect of heat on the properties of steel reinforcement in concrete structures has become a topical interest. In this topic the experience of real-life problems is presented which add immense value to this. This topic also gives a comprehensive knowledge on the overall effect of heat on reinforced concrete then focuses on the effect of heat on steel which is a major component of a reinforced concrete. The aim of this research was to study the effect of heat on the properties of steel reinforcement in concrete structures. The research has been done to find out the effect of the heat on the properties of reinforcement steel bars by heating the bar samples of Y-16mm to temperatures of 100°C, 300 C, 600°Cnand 750°C. The heated samples of Y-16mm, were rapidly cooled by quenching in water and normally cooled by exposure to the atmosphere (air cooling). The change in the mechanical properties are studied using a universal testing machine (UTM). The Yield Strength (YS). Ultimate Tensile Strength (UTS), Fracture Strength (FS) and Elongation were all investigated. It was concluded that there was a steady decline in the strength of the steel bars and the ductility of the bars was affected at elevated temperature above 500°C. In the reinforcement bars it was observed that there is significant reduction in ductility and significant reduction in strength when rapidly cooled by quenching. In the same case when cooled in normal atmospheric conditions the effect of temperature on ductility is not high but the strength is significantly affected. By heating the reinforcement bars, the mechanical properties can be changed which could affect the structure.