In the design of reinforced concrete structures, safety is the most important limit state but serviceability must also be satisfied for appropriate design.
Serviceability usually refers to control of deflections and crack widths at service loads.
This presentation deals with the control of deflections. In the current ACI 318-95 Code, there are two methods to control deflections. The first one is to use the indirect method of minimum thickness. The second one is to directly calculate deflections within the maximum allowable values specified in ACI Code if the minimum thickness value is not satisfied. However, the current minimum thickness values are limited for application to a range of design conditions.