This question asks about the required percentage content of silica (SiO2) in good quality brick earth.
Silica Role in Brick Earth
Silica, usually in the form of sand or fine quartz, is a major component of brick earth. Its primary role is:
- To provide plasticity to the clay during molding.
- To prevent shrinkage and cracking during drying and burning.
- To form hard, durable bricks when burnt.
Ideal Silica Content
For good quality bricks, the percentage content of silica in the brick earth should be within a specific range to balance workability and final properties. Excessive silica can make the bricks porous and weak, while insufficient silica can lead to shrinkage issues.
The generally accepted ideal range for silica content in good quality brick earth is approximately 50% to 60%.
Matching with Options
Comparing this range with the given options:
- Option A: 20-30% (Too low)
- Option B: 30-40% (Too low)
- Option C: 40-50% (Acceptable, but not optimal)
- Option D: 50-60% (Optimal range for good quality bricks)
Therefore, the percentage content of silica in a good quality brick earth falls within the 50% to 60% range.
Important Questions from Bricks and Mortar
The Indian standard brick size is
Statement (I): Bricks are soaked in water before using in brick masonry for removing dirt and dust.
Statement (II): Bricks are soaked in water before using in brick masonry so that bricks do not absorb moisture from the bonding cement mortar.
Mortars for masonry construction are designated based on their strength as per IS: 2250 and IS: 1905, with classifications including $L_1, L_2, H_1, H_2, M_1$ and $M_2$. What is the correct sequence representing the decreasing order of strength for these designations?
The mortar mix proportion used in brick masonry is generally taken as
As per Indian Standard, the modular size of bricks is-
