Stress and Strain Curve of Concrete in Compression

Stress and strain curve of concrete in compression is an important characteristic of concrete which represents the behavior of concrete under compressive loading. This curve is obtained by testing the cylindrical specimen of concrete under uniform rate of strain. The correct option is 'A'.

Uniform Rate of Strain

Uniform rate of strain is the rate at which the strain is applied to the concrete specimen. This rate is kept constant during the testing of the specimen. Uniform rate of strain is preferred over uniform rate of stress as it provides a better representation of the true behavior of concrete under compressive loading.

Testing of Cylindrical Specimen

Cylindrical specimen of concrete is used for testing the stress and strain curve of concrete in compression. The diameter of the specimen is usually 150 mm and the height is usually 300 mm. The specimen is placed in a testing machine and is subjected to a uniform rate of strain. The load is applied continuously until the specimen fails.

Stress and Strain Curve

The stress and strain curve of concrete in compression is obtained by plotting the stress (load per unit area) against the strain (change in length per unit length). The curve shows the behavior of concrete under compressive loading from the initial stage to the failure stage. The curve has two distinct parts – the elastic part and the plastic part.

Elastic Part

The elastic part of the curve represents the behavior of concrete under small stress. In this part, the curve is linear and shows a proportional relationship between stress and strain. The slope of the curve in this part is known as the modulus of elasticity.

Plastic Part

The plastic part of the curve represents the behavior of concrete under large stress. In this part, the curve is non-linear and shows a non-proportional relationship between stress and strain. The curve in this part shows a gradual increase in strain with the increase in stress until the concrete fails.

Conclusion

The stress and strain curve of concrete in compression is an important characteristic of concrete which provides valuable information about the behavior of concrete under compressive loading. The curve is obtained by testing the cylindrical specimen of concrete under uniform rate of strain.