Mortar is the mix ratio of cement and sand for binding of brick masonry or stone masonry. Mortar is also used for finishing a face of wall, ceiling or any other uneven surface of construction work.
Other than cement and sand, there may be lime, Pozollana also used in a fix proportion to obtain better workability. Lime is used instead of cement material.
Mortar material in Mix ratio
Different types of binding material is used to make a smooth mortar material, these constituents are as follows
Cement is major constituents for strength. Generally Portland 43 grade cement is used for the mortar mixing.
Cement is easily available material and every meson is well known with cement mortar so most commonly used mortar mixing material.
Curing is necessary for the cement mortar.
lime is another binding material used for making of mortar, but it is not easily available and mesons are not so familiar with this so lime is not so common nowadays.
This imparts less strength than cement whereas the workability is increased with the help of lime.
Pozzalana is not so common and used in rare case.
Sand is major contributor in the volume of any types of mortar because it is similar material and easily available with low cost.
It is necessary to used well graded sand for the better result in compressive strength of mortar after 28 days of cube compression test.
If well graded sand is not available then the ratio of sand can be changed as per local requirement and testing.
MORTAR MIX RATIO
Mortar is mixed in different proportion best on requirement of strength of mortar material.
The most common mortar mix ratio for wall plastering is 1:6, here 1 part is cement and 6 part is sand in a workable amount of water.
The strength of 1:6 ratio of mortar after 28 days is 3.0 N/mm2.
The strength can be increased upto 2.0 N/mm2 by decreasing one portion of sand. i.e. 1:5 ratio of mortar impart compressive strength of 5.0 N/mm2 after 28 days of cube testing.
If you require more strength, then 1:4 ratio is best suited. it gives 7.5 N/mm2 of compression strength.
The thickness of mortar is varied as per the work and load on work.
Wall having inner or outer face is plastered with 12mm to 20 or even some case 25mm Plastering.
Ceiling plaster is done with 6 mm thickness of mortar.
Same case is used in brickwork or stone masonry, the thickness is near about 12mm is common for better result.
If you want to calculate cement sand quantity in plastering read here