Consider the following statements: The addition of surfactants in the concrete mix results in: 1. increase in the water-cement ratio 2. decrease in the water-cement ratio 3. increase in the strength of concrete 4. decrease in the curing duration 5. increase in the density of concrete Which one of the following statements is correct?

Consider the following statements: The addition of surfactants in the concrete mix results in: 1. increase in the water-cement ratio 2. decrease in the water-cement ratio 3. increase in the strength of concrete 4. decrease in the curing duration 5. increase in the density of concrete Which one of the following statements is correct? Correct Answer 2, 3 and 5 only

Explanation:

• The introduction of suitable surfactants into the concrete mix results in the formation of fine and stable air bubbles.
• When the fresh mixture begins to cure, the bubbles within it become mineralized and become an integral part of it. In this way, additional space is created inside the concrete structure inside which the freezing water expands.
• This prevents an increase in internal pressure, which is responsible for the formation of cracks during low temperatures.
• As the voids in concrete are reduced, so less water is required to lubricate the mix, thus the water-cement ratio will be decreased, and the strength of concrete will be increased. The addition of surfactants will increase the density of concrete.