1.1 Reinforced Concrete
1.1.1 Deﬁnition of Reinforced Concrete
Reinforced concrete is concrete in which reinforcing bars or other types of reinforcement have been integrated to improve one or more properties of the concrete. For many years, it has been utilized as an economical construction material in one form or another in buildings, bridges, and many other types of structures throughout the world. A large part of its worldwide appeal is that the basic constituent materials—cement, sand, aggregate, water, and reinforcing bars—are widely available and that it is possible to construct a structure using local sources of labor and materials. In addition to being readily obtainable, reinforced concrete has been universally accepted because it can be molded essentially into any shape or form, is inherently rigid, and is inherently ﬁre-resistant. With proper protection of the reinforcement, a reinforced concrete structure can be very durable and can have a long life even under harsh climatic or environmental conditions. Reinforced concrete structures have also demonstrated that they can provide a safe haven from the potentially devastating effects of earthquakes, hurricanes, ﬂoods, and tornadoes. Based on these and other advantages, it is evident that reinforced concrete can provide viable and cost-effective solutions in a variety of applications. This book focuses on the design of reinforced concrete members in building structures.
1.1.2 Mechanics of Reinforced Concrete
Concrete is a brittle, composite material that is strong in compression and weak in tension. Cracking occurs when the concrete tensile stress in a member reaches the tensile strength due to externally applied loads, temperature changes, or shrinkage. Concrete members that do not have any type of reinforcement in them will typically fail very suddenly once the ﬁrst tension cracks form because there is nothing to prevent the cracks from propagating completely through...