Common Defects in Bricks: Causes, Effects, and Prevention

Common Defects in Bricks: Causes,
Effects, and Prevention

Bricks are a fundamental building material used in construction. However,
various defects can occur during the manufacturing process, affecting the
quality and durability of bricks. Understanding these defects, their causes,
effects, and prevention methods is crucial for ensuring the structural
integrity of brickwork. This post will explore common defects in bricks and
provide insights into how to prevent them.

Common Defects in Bricks: Causes, Effects, and Prevention

Table of Common Defects in Bricks

Detailed Analysis of Defects

1. Over-burning of
   Bricks:
• Effect: Produces a
  soft molten mass, leading to loss of shape.
• Prevention: Monitor and
  control the kiln temperature to avoid excessive heat.
2. Under-burning
   of Bricks:
• Effect: Results in
  higher water absorption and lower strength.
• Prevention: Ensure
  sufficient heat exposure during the burning process to close pores and
  achieve desired strength.
3. Bloating:
• Effect: Spongy,
  swollen mass on brick surface.
• Prevention: Control the
  amount of carbonaceous matter and sulphur in the clay.
4. Blackcore:
• Effect: Bricks
  develop a black core due to impurities.
• Prevention: Ensure
  complete removal of impurities like carbon and manganese through proper
  oxidation during burning.
5. Efflorescence:
• Effect: White powder
  patches form on the brick surface.
• Prevention: Use clean,
  quality materials and proper curing techniques to minimize alkali
  content.
6. Cracks or
   Checks:
• Effect: Caused by
  lumps of lime or excess water.
• Prevention: Use
  well-processed clay and control the amount of water in the mix.
7. Spots:
• Effect: Dark surface
  spots due to sulphide.
• Prevention: Avoid using
  clay with high sulphide content.
8. Blisters:
• Effect: Broken
  blisters on brick surface.
• Prevention: Ensure proper
  moulding techniques to avoid air entrapment.
9. Laminations:
• Effect: Weak
  laminations on brick faces.
• Prevention: Properly
  compact the clay to remove air voids.
10. Chuffs:
• Effect: Deformation
  of brick shape.
• Prevention: Protect hot
  bricks from exposure to rainwater.

FAQs

1. What causes
   over-burning of bricks?
• Over-burning
  of bricks occurs when bricks are exposed to excessive heat, resulting in
  a soft molten mass and loss of shape. Such bricks are unsuitable for
  construction.
2. How can
   under-burning of bricks be prevented?
• Under-burning
  can be prevented by ensuring that bricks are exposed to sufficient heat
  during the burning process to close the pores and achieve the desired
  strength.
3. What is
   efflorescence in bricks, and how can it be avoided?
• Efflorescence
  is caused by alkalies present in bricks that form white powder patches on
  the surface when in contact with moisture. It can be avoided by using
  clean, quality materials and proper curing techniques.
4. Why do bricks
   develop blackcore, and what are its implications?
• Blackcore
  develops when impurities like carbon and manganese are not completely
  removed during burning. It indicates improper burning and can affect the
  brick’s strength and appearance.
5. What are the
   effects of sulphide spots on bricks?
• Sulphide spots
  cause dark surface spots on bricks, making them unsuitable for exposed
  masonry work and potentially harmful due to the presence of sulphides.

Conclusion

Understanding the common defects in bricks, their causes, and prevention
methods is essential for producing high-quality bricks and ensuring the
longevity of brick structures. By addressing these issues during the
manufacturing process, builders can avoid potential structural problems and
maintain the integrity of their constructions.