Correct Answer - Option 1 : More economical
Explanation:
Methods of designing an RCC structure:
There are 3 methods of design an RCC structure:
1. Working stress method:
- This was the traditional method of design.
- The method basically assumes that the structure behaves in a linear elastic manner.
- The actual stresses developed due to the actual working load.
- Stresses developed are kept within permissible stress value.
- The factor of safety is applied to stress values only.
- The design usually results in relatively large sections of the structural members.
2. Ultimate load method:
- This method is sometimes also referred to as the Load factor method.
- In this method, the stress condition at the site of the impending collapse of the structure is analyzed, and the nonlinear stress-strain curves of concrete and steel are made use of.
- The concept of modular ratio and its associated problems are avoided entirely in this method.
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This method is more economical than the working stress method.
3. Limit state method:
- A condition of the structure once achieved, the structure cannot perform its intended function satisfactorily in the future in terms of safety or serviceability.
- Condition of a structure, once achieved the structure cannot be used satisfactorily in future is called limit state condition.
- Limit state can be achieved due to Limit state of collapse and Limit state of serviceability.
- This method is based on the Ultimate Strength of the structure, satisfactory performance at the working stage, and satisfying the serviceability & durability requirements.
