Question

What is carbonation shrinkage?

(a) It is not a result of any change in the concrete production process. Rather, it is a result of certain environmental conditions which frequently occur in the Central Missouri area

(b) It is defined as the contracting of a hardened concrete mixture due to the loss of capillary water. This shrinkage causes an increase in tensile

(c) It is an important phenomenon in young concrete. At low w/c ratios, less than about 0.42, all the water is rapidly drawn into the hydration process and the demand for more water creates very fine capillaries

(d) It occurs when the concrete is exposed to air containing carbon dioxide

The question was asked in an internship interview.

Question is taken from Types of Shrinkage in chapter Elasticity, Creep and Shrinkage of Concrete Technology

Answer 1

The correct answer is (d) It occurs when the concrete is exposed to air containing carbon dioxide

Easiest explanation: It occurs when the concrete is exposed to air containing carbon dioxide.