Reinforced concrete structures without prestressing generally crack and in some cases have excessive deflection. If some of the reinforcement is prestressed steel, cracking and deflection can be controlled. The amount of prestressing may be sufficient to avoid cracking. This condition is referred to as full prestressing, as opposed to partial prestressing where controlled cracking is allowed. Partial restressing is widely used and is often considered preferable to the two extremes of no prestressing and full prestressing. When full prestressing is adopted, non prestressed steel is commonly provided to control cracking due to temperature and shrinkage.
