Mechanical Properties of Reinforcing and Prestressing Steels after Heating

Abstract

This paper reports test results showing how the heating-cooling process like the one occurring during fire action can affect the tensile strength and the strain after rupture of the steels normally used in reinforced and prestressed concrete structures. Laboratory tests were carried out to assess the values of these properties after heating. In these tests, steel samples were heated up to different temperature levels followed by a cooling process. Cooling in the air, cooling by water jet, and cooling by total immersion in water with agitation were the cooling processes used. For temperatures up to 600°C, the tested reinforcing steel showed no major alterations. However, for temperatures above 700°C, important changes in the steel properties could be observed. For the prestressing steel, those alterations began at 400°C.