Working Stress Method in Reinforced Concrete Design

The working stress method is one of the common methods used to design reinforced concrete structures. In this method, the stress in the concrete and steel is calculated based on their allowable stresses. The stresses are then compared with the strength of the materials to ensure that the structure is safe and can withstand the loads.

Permissible Compressive Stress

Permissible compressive stress is the maximum stress that a concrete can withstand without causing any permanent deformation or failure. The permissible compressive stress of concrete depends on its grade and is usually given by the manufacturer.

Modular Ratio

Modular ratio is defined as the ratio of the modulus of elasticity of steel to that of concrete. It is denoted by the symbol n and is used to convert the stress in the steel to the corresponding stress in the concrete.

Calculation of Modular Ratio

As per the working stress method of reinforced concrete design, the modular ratio is approximately given as 93/p, where p is the permissible compressive stress of the concrete.

Explanation of Answer

Option A is the correct answer as it represents the formula for calculating the modular ratio as per the working stress method of reinforced concrete design. The other options, B, C, and D, are not correct as they represent different values of the modular ratio formula.

Conclusion

The working stress method is a widely used method to design reinforced concrete structures. The modular ratio is an important parameter used in this method, which helps to convert the stress in the steel to the corresponding stress in the concrete. The formula for calculating the modular ratio is 93/p, where p is the permissible compressive stress of the concrete.