Illustrates about the need for reinforcement?

NEED FOR REINFORCEMENT

Concrete is economical and durable and is currently universally utilized for footings. Plain concrete is adequate to carry relatively light loads. The minimum plan dimensions are decided by the safe bearing capacity. Usually, the load distribution through the footing is assumed to be independent of the material and to occur at 45 "as demonstrated in figure:

Plain Concrete Footing for a Brick Wall

The thickness of the footing should be sufficient so that column loads can be spread through them at 45 " dispersion to give uniform bearing pressure less than allowable bearing capacity. Stepped or sloped footings are most commonly used to reduce the concrete away from the column where the bending moment and shear forces are small. As the load increases, the thickness of the footing increases. Quantities of concrete increases and deeper excavations have to be made. Beyond a certain thickness, you may find it more economical to use reinforcement in the footing than plain concrete. The thickness of the footing will then be reduced. Also excavation will be less.