Reinforced concrete beams and columns

This chapter presents the basic theory governing the design of reinforced concrete (RC) members subjected to bending and compression. The design of beams in bending and shearing is considered, as well as the basic applications of mechanics to the detailing of reinforcement and the calculation of the minimum area of reinforcement. The control of deflections is not considered, because the stiffness of RC beams is difficult to assess due to cracking, which is normal in RC beams. Because of this, deflections are normally controlled by empirical methods involving span-to-depth ratios. The chapter considers the design of columns and shows how to construct moment versus axial force design charts. During design, the objective is to ensure that the shear resistance is greater than the applied shear force. Concrete has an inherent shear capacity in the absence of shear links. The surface of rebar is ribbed to prevent slippage through the concrete. RC is a composite of steel and concrete.