Question

study of flexure of a bar

Answer 1

While much attention has been given to the effect of the variability of concrete strength and properties on the response of reinforced concrete structures, there is little, if any, information on the effects of variability of steel strength. This lack of interest may be explained by the assumed assurance that steel manufactures are always complying with minimum code specifications. However, steel mechanical properties are sometimes exceeding the minimum nominal strength values for a specific grade of steel. This happens in many countries as there are different steel producers who adopt different methods of manufacturing. The mechanical properties of steel are governed by the production technique, chemical compositions, mechanical working of rebar, and the method of heat treatment as described by (Davis et al., 1982). Seismic standards have been developed with the aim of allowing steel to yield without rupture during an earthquake, in order to enhance seismic energy absorption of the structure and avoid collapse. For this purpose, steel bars should possess high strength with sufficient ductility and low variation in yield strength to experience large number of inelastic cycles of deformation with large plastic strains. In this regard, most international specifications outline and control the mechanical properties requirements for rebar to be used in seismic resistant systems as reported by (Milbourn, 2010)