Methods of R.C.C. Design

Various method used for the design of R.C.C. structure are as follows:
  1. Working stress method
  2. Limit state method
  3. Ultimate load or load factor method
1.working stress method:- This method of design was the oldest one. It is based on the elastic theory and assumes that both steel and concrete are elastic and obey Hook's law. It means that the stress is directly proportional to strain up to the point of collapse. Based on the elastic theory, and assuming that the bond between steel and concrete is perfect, permissible stresses of the materials are obtained.
          In this method, the ultimate stresses of concrete and yield strength or 0.2% proof stress of steel are divided by factor to obtain permissible stresses.

2.Limit state Method:- This us the most rational method which takes into account the ultimate strength of the structure and also the serviceability requirements. The acceptable limit of the safety and serviceability requirements before failure occurs is called limit state.




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