In this tutorial, we’ll introduce the role of steel reinforcement in reinforced concrete design. We’ll see that steel plays a critical role in developing an internal moment of resistance and compensates for concrete’s inherent brittleness and weakness in tension. We’ll explore the fundamental mechanical model used to describe the behaviour of the cross-section under load. We’ll also see that to avoid a brittle failure, we must limit the depth of the neutral axis at the ultimate limit state. After reading this tutorial, you’ll have a good understanding of how to perform concrete section analysis and basic design.