QUALITIES OF SAND FOR MORTAR

Sand particles are small soil grains of silica. As per the Indian Soil Classification, particles of diameter greater than 0.075 mm and less that 4.75 mm are categorized as sand.

Sand is naturally available and may be classified as (i) pit sand, (ii) river sand and (iii) sea sand. Sea sand is not suitable for mortar.

For the purposes of mortar, sand is classified as fine, coarse and gravelly sand. Fine sand is one that passes through a screen with clear openings of 1.59 mm, coarse sand passes through a screen with clear openings of 3.18 mm and gravelly sand passes through a screen with clear openings of 7.62 mm. Fine sand is used for plastering, and coarse sand is used for masonry work.

The properties of sand required for mortar are as follows:

1. It should be free from any organic matter.
2. It should be chemically inert.
3. It should be well graded.
4. The fineness modulus of sand should be between 2 and 3.
5. It should be sharp, angular, coarse and clean.