DESIRABLE PROPERTIES OF MORTAR

 DESIRABLE PROPERTIES OF MORTAR

A mixture of cement, lime, fine aggregates and water makes up mortar. Cement and lime act as binding agents and fine aggregates are known as matrix. Their combined effect makes up the perfect binding agent which is also capable of providing strong joints.

Apart from the above mentioned facts, mortars are required to project certain properties:

• WORKABILITY: As the name suggests, mortar should be fluid and easy to work with. This includes being able to reach and fill the joints properly without any gaps. 
• RATE OF STIFFENING: As the amount of water reduces in mortar due to evaporation, it starts to become stiff and hard.  As stiffening accelerates, so does the rate of early strength development. Hence, mortars should have a high rate of stiffening.
• VOLUME CHANGE: Mortar is required to undergo minimum change in volume as this sets the standard of strength of bond. Higher the volume change, poor is the initial bond, hence poor strength.
• GOOD ADHESION: Since mortar is a binding agent, it is natural to expect good adhesion property because it will decide the strength of bond.
• COMPRESSIVE STRENGTH: As the structure undergoes compression, naturally mortar should have the desired compressive strength to counter the forces.
• DURABILITY: Higher durability means low maintenance and high strength.