Q. How to test the quality of Bricks at small construction sites?
Normally the bricks are tested for Compressive strength, water absorption, dimensional tolerances and efflorescence. However at small construction sites the quality of bricks can be assessed based on following, which is prevalent in many sites.
1. Visual check - Bricks should be well burnt and of uniform size and color.
2. Striking pf two bricks together should produce a metallic ringing sound.
3. It should have surface so hard that can’t be scratched by the fingernails.
4. A good brick should not break if dropped in standing position from one metre above ground level.
5. A good brick shouldn’t absorb moisture of more than 15-20% by weight, when soaked in water For example, a good brick of 2 kg shouldn’t weigh more than 2.3 to 2.4 kg if immersed in water for 24 hours.
Q. What is the importance of Frog (depression in the brick) in masonry?
The depression in the brick on top (approximately 100mmX40mm X10 to 15mm deep) is called the frog and the mortar is filled in the frog while laying the bricks in masonry work to help in bonding and acting as a shear key against horizontal loads.
Q. What precautions to be taken in brick masonry work?
1. Bricks should be soaked in water for adequate period so that the water penetrates to its full thickness. Normally 6 to 8 hours of wetting is sufficient.
2.A systematic bond must be maintained throughout the brickwork. Vertical joints shouldn’t be continuous but staggered.
3. The joint thickness shouldn’t exceed 1 cm. It should be thoroughly filled with the cement mortar 1:4 to 1:6 (Cement: Sand by volume)
4. All bricks should be placed on their bed with frogs on top (depression on top of the brick for providing bond with mortar).
5. Thread, plumb bob and spirit level should be used for alignment, verticality and horizontality of construction.
6. Joints should be raked and properly finished with trowel or float, to provide good bond.
7. A maximum of one metre wall height should be constructed in a day.
8. Brickwork should be properly cured for at least 10 days.
Q. How many days of curing are adequate for Brickwork?
The brickwork should be cured with water and kept moist for minimum 7 to 10 days period for proper development of strength.
Q. What is the difference between a load bearing masonry structure and RCC framed building?
Load-bearing masonry structure transfers the structural load of the building through the masonry walls and masonry footing and do not have concrete columns and footing. A RCC framed building would have columns (pillars) arising out of foundations, which bear the load of the building through column-beam frame and transfer the load to foundation. Load bearing walls are not economical in most cases if the building has more than three stories. RCC framed system is slender and having flexibility of shifting it’s internal light weight partition walls.