3-Types of Limes and their classification; lime mortar
Types of Limes and their classification
It’s a very important binding material used in building construction work. The Lime has been used in civil engineering as the material of construction work from the earliest time lime mortar; When it was mixed with the sand it provides lime and when mixed with the sand and coarse aggregate (40mm), it forms lime concrete for the foundation works.
- Fat lime. (1st)
2. Hydraulic lime (2nd)
3. Poor lime. (3rd)
- It is composed of 95 per cent of calcium oxide. When water is added, it slakes
vigorously and its volume increases to 2 to 21/2
times. It is white in color. Its properties are:
(a) hardens slowly
(b) has a high degree of plasticity
(c) sets slowly in the presence of air
(d) white in colour
(e) slakes vigorously.
- It contains clay and ferrous oxide. Depending upon the percentage (%) of clay soil present, hydraulic lime is divided by the following three types are given below.
- Feebly hydraulic lime (5% – 10% clay content)
2. Moderately hydraulic lime (11%- 20% clay content)
3. Eminently hydraulic lime (21% – 30% clay content)
The properties of hydraulic lines are:
- Sets underwater
- Colour is not perfectly white
- This Forms are thin paste with the water and do not dissolve in water.
- Its binding property improves if its fine powder is mixed with sand and kept in the form of the heap for a week, before using.
- It contains more than 30% clay. Its colour is muddy. It has poor binding property. The lime made with such as lime is used for in inferior works.
Class A Lime:
It is predominantly hydraulic lime. It was normally supplied as the hydrated lime and it was commonly used for structural works in construction works.
Class B Lime:
It contains both hydraulic lime and fat lime. It’s supplied in a hydrated lime or quick lime. It’s was used for making lime for masonry works in construction.
Class C Lime:
It was predominantly fat lime type, it is supplied both as the quick lime type and fat lime types. It was used for the finishing coat in plastering and whitewashing works in construction.
Class D Lime:
This lime contains a large quantity of magnesium oxide and is like fat lime. This is also commonly used for whitewashing and for finishing coats in plastering.
Class E Lime: It is an impure limestone, known as kantar. It is available in modular and block form. It is supplied as hydrated lime. It is commonly used for masonry mortar.