Correct Answer - Option 4 : White lime
Explanation:
Different types of lime:
Fat lime:
(i) This lime slake vigorously due to which it's volume increases by 2 to 2.5 times than it's original volume. Hence it is referred as fat lime.
(ii) It posses perfectly white colour, hence also termed as white lime.
(iii) It is obtained by the calcination of lime stone of approx. 95% purity, hence it is also referred as pure lime, rich lime or highly caustic lime.
(iv) It's properties are:
- It hardness very slowly with vigorous slaking.
- It has good solubility in water
- It possesses a high degree of plasticity.
- In the presence of air it sets slowly
- Fat lime is mostly used for plastering and white washing.
Hydraulic lime:
(i) It is also referred as water lime as it is capable of setting in water and in damp locations.
(ii) It is obtained by the calcination of lime stone having the purity in the range of 70 - 92%.
(iii) It is insoluble in water and possess off white colour.
(iv) It hardness comparatively faster than fat lime, hence is used in engineering works where strength is require. Ex: Brick masonry and stone masonry
Poor lime:
(i) It is also referred as impure lime or lean lime as it obtained from the calcination of lime stone having purity less than 70%.
(ii) This lime does not undergoes slaking, hardness very slowly, possess muddy white colour, hence is used in Engineering works of minor importance. Ex: Brick work around foundation.
