Influence of rebar design on mechanical behaviour of Tempcore steel

Abstract

Tensile behaviour of metals beyond the ultimate tensile strength (UTS) must be considered to calculate toughness or absorbed energy till fracture. Structural steels, designed to withstand earthquakes, are the typical material where post necking behaviour can be of paramount importance. This paper deals with the tensile stress-strain behaviour of Tempcore Rebar, a specifically shaped structural steel. Helical, short ribs, formed by rolling, protrude from the cylindrical basic shape of the Rebar. This help in increasing concrete/steel adherence in reinforced structures. On the other hand, those ribs make it difficult to assess strain distribution in the necking area, according to well-known theories describing neck profile. New or modified experimental methods, along with new theoretical approaches must be developed to help in studying neck profile evolution and corresponding stresses in rebars. Advances in such methods and theories are presented in this paper along with comparison with Tempcore cylindrical bars necking behaviour. The effect of ribs is clearly identified.