In relation to brick work the mortar can be defined as the gap filling adhesive which evens out any slight irregularities in size and shape of bricks to give an even bed and ensuring the uniform distribution of loads. The mortar also influences the compressive strength, durability and resistance to rain penetration through brickwork.
Generally mortar consists of a binder, an aggregate and water, to which plasticizers, coloring pigments etc. may be added as required.
The selection of a suitable mortar mix is vital. The compressive strength, cost to be incurred at site and the workability are some factors that should be considered in this regard. The higher cement content would increase the strength but in non-load bearing constructions like this the strength is not the main criteria. Also the lower cement content has a positive effect on the workability in addition to water. Thus in the site we used 1:5 (cement: sand) mixture with adequate amount of water adjusted according to the workability.
The overlapping arrangement of bricks in order to tie them together to form the brickwork is termed as the ‘bonding’. It is very important to do the bonding accurately as the bond governs the strength of the wall. The selection of a proper bond pattern and adopting it correctly is very important in this regard.
All the 9// walls in our site are done in English bond while the 4 ½ // walls are done in Stretcher bond.
To ensure satisfactory bondage the following points should be adhered to.
- Good bonding should have a minimum of vertical joints in any part of the work, and it should not be continuous in two successive courses since it is a source of weakness.
- The lap should be one fourth of a brick as much as possible.
- The bricks should be uniform in shape and size. The length of the brick should be equal to twice the width of the brick plus thickness of one mortar joint.
- The vertical joints should be vertically above each other in the alternate courses.
- The stretchers should be used only in the facing, while hearting should be done in hearts only.
- The centerline of the header should coincide with the center of the stretcher in the course below or above it.
Least number of bats should be used.