Characterisation of steel reinforcement for RC structures: An overview and related issues
P. Prabir C. Basu, Shylamoni P. and Roshan A. D.
Characterisation of steel reinforcement is as important as that of concrete ingredients. The paper presents an overview of characterisation along with some related issues. After briefly highlighting the mechanics of RC structures, important characteristics of reinforcement, namely, bond with concrete, strength, ductility, resistance to corrosion are discussed. The effects of manufacturing process on the rebar characteristics are then described. Finally, a comparison of specifications of standards of different countries dealing with reinforcing steel is presented. The authors have suggested certain modifications in the Indian specifications IS 1786.
Steel is the time proven match for reinforcing concrete structures. Reinforced concrete structure is designed on the principle that steel and concrete act together to withstand induced forces. The properties of thermal expansion for both steel and concrete are approximately the same, this along with excellent bendability property makes steel the best material as reinforcement in concrete structures. Another reason steel works effectively as reinforcement is that it bonds well with concrete. When passive reinforcement (steel bars) is employed, the structure is known as reinforced concrete (RC) structure. In prestressed concrete structure, the reinforcement (steel wire) is stressed prior to subjecting the structure to loading, which may be viewed as active reinforcement. Passive steel reinforcing bars, also known as rebars, should necessarily be strong in tension and, at the same time, be ductile enough to be shaped or bent. Rebars are rolled from billets that are obtained from a furnace. Billets can be produced either from iron-ore through the blast furnace converter route, or by melting scraps and refining the same in the furnace. When billets are produced from scrap, they are...