What is lime Mortar? -

Lime Mortar: Introduction

Lime mortar is ancient Indians first used mortar for temples, forts and historic structure
It is typically used as plastering, masonary (either stone or bricks) and as a binding material.

There are two types of lime is there,
1. Hydraulic lime Mortar
1. Fat lime Mortar
Classification of Mortar: Read more>>>

In this mortar hydraulic lime and sand in 1:2 ratio is used in very damp conditions
Mostly it is suitable for waterlogged areas.

fat lime is used and the quantity of fat is lime is almost 2 to 3 times greater than sand requirements in fat lime mortar
Mainly this type of mortar is used in dry work, where the high plasticity is required.

Lime mortar is mortar in which lime (hydraulic lime or fat lime) is used as binding material in combination with sand and water.
Basically, fat lime and hydraulic lime is used in lime mortars.
Fat lime mortar is used commonly and for damp situations hydraulic lime mortar is used
It is ancient type of mortar and widely used in historic structures along with stones.

It is more plastic and workable when it is wet in condition.
It has good workability and working properties when it made from excessive calcium lime.
It also develops slow lateral strength for very long time.
It does not set by action of water loss due to absorption and evaporation.
Provides strength and strong surface if used in plastering.
It provides strong bond between the joints when used in masonary joints.

Lime mortar can be re worked for up to 24 hours as it has great setting time.
It reduces the wastage when used in silos structures.
It reduces the movement in joints.
It possesses the constant prime quality and colour of mortar.
As it possesses constant colour, it enhances the masonary joints in various masonary.
It also acts as water shedding barrier when used in masonary.
This provides the breathable types of construction.
By the end of the finish of life, this mortar also permits masonary to be recycled.
It absorbs the CO₂ while curing processes.
Makes use of much less energy to produce than cement.

Quick setting time of lime mortar has limitations on casting.
Lime mortar can not be repaired with cement mortar as it does not form bond between lime and cement mortar when it gets harden.
An excessive amount of initial chemical set ignores the importance of extended carbonation of the non-hydraulic component.
The danger that segregation occurs, whereby the cement separates from the lime as the mortar dries and hardens.
The use of cement leads the consumer to deal with gold lime mortars as it has been purely hydraulic lime or cement.
Ph of mortar drops about 8.6 when lime mortar get dried and harden.

The Lime mortar can be used as plastering, joinery and in masonary.

For Foundation Works: fat lime mortar can be used in all types of foundation work in dry sub grade – water table is 2.4 m below the foundations level.
For All Masonry Works: loading – 20 to 60 tonnes/m² (light and medium loading)
- Fat lime and hydraulic lime, both are suitable.
- Lime mortar can be replaced by cement mortar.
- To bind stones, bricks or concrete blocks together

Lime mortar cannot be applied when:

Sub grade soil is moist water table is within 2.4 m.
- Heavy loading is expected.
- Construction is massive and very thick.

Mortars with hydraulic lime should be used within 4 hours after mixing.
Lime mortars with surkhi should be used within 24 hours after mixing.
Composite (lime and cement) mortars should be used within 2 hours after mixing.
All lime mortar shall be kept wet after grinding.
The workers who are to handle lime mortar should protect their skin by using oil, rubber gloves etc.