Which one of the following is NOT correct for characteristics of lime?
- ALime possesses good plasticity and is easy to work with.
- BIt stiffens easily and is resistant to moisture.
- CThe excellent cementitious properties make it most suitable for masonry work.
- DThe shrinkage on drying is large because of its high water retentivity.Correct
Solution
Concept
Lime has high water retentivity, so it loses water slowly and its shrinkage on drying is small, not large.
Step-by-step solution
1. List the standard properties of lime: good plasticity, easy to work, stiffens easily, resists moisture, and has good cementing value for masonry. 2. High water retentivity means water is held in the mix for longer. 3. Because the mix dries slowly, shrinkage on drying is small. 4. Option D says shrinkage is large, so it is NOT correct. 5. So the answer is (D).
Explanation
Lime holds water well, which is called high water retentivity. Because of this it dries slowly and the shrinkage on drying is small. Statement D says the shrinkage is large, so it is wrong.
Why the other options are wrong
A, B and C are standard textbook properties of lime: good plasticity and workability, easy stiffening with moisture resistance, and good cementing value for masonry.
Shortcut
High water retentivity leads to slow drying and less shrinkage.
Common mistake
Thinking that high water content always means more shrinkage.
Correct answer: D) The shrinkage on drying is large because of its high water retentivity.