Consider the following statements:

1) Hydrophobic cement grains possess the low wetting ability

2) Rapid-hardening cement is useful in concreting under static, or running water

3) Quick-setting cement helps the concrete to attain high strength in the initial period

4) White cement is just a variety of ordinary cement-free of coloring oxides.

Which of the above statements are correct?

Sr no

Type of cement

Key points

1.

 Hydrophobic cement

1. It contains 0.1-0.4% oleic acid and stearic acid
2. Due to the presence of oleic acid, a film is formed surrounding the grains of cement, which acts as a water repellent film. Hence it has a low wetting ability.
3. It is useful in humid places.

2.

 Rapid hardening   cement

1. Also known as high early strength cement.
2. The curing period is less.
3. It hardens fast but has the same setting time as OPC.
4. It is useful in cold weather concreting.
5. Not used for a massive concrete structure.

3.

 Quick-setting cement

1. Quick setting cement also is known as fast setting cement or rapid set cement has less initial and final setting time.
2. It sets quickly so the cement paste can take the required shape rapidly.
3. It has an initial setting time of 5 minutes and a final setting time of 30 minutes.

 White cement

1. The white color of cement is due to the low percentage of iron oxide (in negligible percentage).
2. It is ordinary cement-free of coloring oxides.

5.

 Low heat Portland   cement

1. It has a low percentage of C₃S, C₃A, and a high percentage of C₂S.
2. It has less heat of hydration.
3. Useful for mass concreting.

6.

 Sulfate resisting   cement

1. It contains more amount of silicates and less amount of C₃A, which results in resisting power against sulfates.
2. Used for underwater structures, canal lining, culverts exposed to alkali action.

7.

 High alumina cement

1. It contains about 35% alumina.
2. It sets quickly and attains high ultimate strength in a short time.
3. Use for structures subjected to the action of seawater, chemical plant, and furnaces.