Reinforced concrete is a mixture of concrete and steel. Such a mixture combines the best properties of both materials and overcomes their insufficiencies. Since concrete has a low tensile stress its good for fire resistance. On the other hand, steel has high tensile strength but suffer rapid loss of strength at high temperatures. So, when they are combined together, the steel provide the tensile strength while the concrete protects the steel from high temperature.
A structure refers to a system of a connected parts used to support and carry loads .
In design of reinforced concrete structure the following functions must be taken under consideration:
- Safety
- Serviceability
- Minimum cost
- Environmental constraints
- Esthetics
Before design any structure the first step is to put a primary model and then analysis process must be done to see how members are supported and connected together. The result of this analysis then can be used to design the structure accounting for more accurate determination of dimensions of the members and their other properties.
Design process are mix between science and art. So, they need technical and fundamental knowledge of material properties and laws of mechanics which govern materials response.
The purpose of structure design is to insure that:
- The structure is safe under the worst scenario loading.
- The structure is functional under the service loading condition.
General laws that control all structure system are :
- Stress-strain relationship
- Equilibrium conditions
- Compatibility