Some handy tips to find out the compressive strength of mortar
It is advisable to apply 2 inch or 50mm cubes as stated by ASTM C109 / C109M ? Standard Test Method for Compressive Strength of Hydraulic Cement Mortars to define the compressive strength of mortar.
Mortar is a formed by amalgamating cement, sand mixed with water. Application of mortar is found in masonry works like brick masonry and stone masonry and for plastering walls, columns etc.
Mostly utilized mix ratio of mortar in masonry works range from 1:3, 1:4 and 1:6 of cement to sand ratio. For vital masonry structures like brick walls, 1:3 ratio is applied.
Why Compressive Strength Test of Mortar is Important?
Usually masonry structures are built up as load bearing. As for instance, load bearing walls, load bearing masonry columns etc. are developed for residential and other masonry buildings. For a masonry buildings, foundations are also built up with brick masonry.
Towards a load bearing masonry construction, vital fact is to recognize the compressive strength requirement of masonry to resist the load that operates on it. A masonry wall is likely to deal with compressive loads from floors over it and should contain adequate strength to resist it. Therefore, masonry compressive strength should have been adequate to support the loads on wall.
How to find out the Compressive Strength of Mortar
To determine the compressive strength of standard cement sand mortar cubes, the following apparatus and methods of the test are undertaken :-
Apparatus: 7.06cm cubes moulds (50cm2 face area), apparatus for measuring and blending mortar, vibrator, compression testing machine etc.
Method for checking Compressive Strength of Mortar
Choose 200gm of cement and 600gm of standard sand in the mix ratio 1:3 by weight) in a pan.
The standard sand is made of quartz, of light, gray or whitish variety and does not contain silt. The sand grains is like angular, the shape of grains is similar to the spherical form, extended and flattened grains are found in very small quantities.
Standard sand passes across 2 mm IS sieve and is kept on 90 microns IS sieve with the particle size distribution as given below.