The lime in excess makes the cement unsound and causes the cement to expand and disintegrate
The silica in excess makes the cement stronger but its setting time also increases
The excess amount of alumina weakens the cement
All the above
Answer is Right!
Answer is Wrong!
The correct answer is D. All of the above.
Lime, silica, and alumina are the three main components of cement. The proportions of these components vary depending on the type of cement being produced. However, if any of these components are present in excess, it can have a negative impact on the quality of the cement.
- Excess lime can make the cement unsound and cause it to expand and disintegrate. This is because lime is a basic substance, and if it is present in excess, it can react with the acidic components of the cement to form calcium carbonate. Calcium carbonate is a weak material that is not as strong as the original cement.
- Excess silica can make the cement stronger, but it also increases its setting time. This is because silica is a non-reactive material, and it takes longer for it to react with the other components of the cement. The longer setting time can be a problem in some applications, such as when the cement is being used to make concrete.
- Excess alumina weakens the cement. This is because alumina is an acidic substance, and if it is present in excess, it can react with the basic components of the cement to form aluminum hydroxide. Aluminum hydroxide is a weak material that is not as strong as the original cement.
Therefore, it is important to ensure that the proportions of lime, silica, and alumina in cement are within the correct range. This will ensure that the cement is of good quality and will perform as expected.