Correct option is D
Efflorescence is a crystalline, salty deposits that occurs on surface of bricks. It occurs when alkali salts are present in the bricks. Water on evaporation leaves behind the salts on the surface of the brick which give rise to efflorescence
Efflorescence is a crystalline deposit of salts that can form on the surface of bricks, concrete, and other building materials. It occurs when water carries salts to the surface, where it evaporates, leaving behind a white, powdery residue.
Causes of Efflorescence:
Alkalies: The primary cause of efflorescence in bricks is the presence of alkalies such as sodium sulphate, potassium sulphate, or other soluble salts in the bricks. These alkalies can come from the clay used in brick production, from the mortar, or from external sources like soil or water. When moisture penetrates the brick, it dissolves these salts, which are then carried to the surface by the evaporating water, resulting in efflorescence.
Lime, Organic Matter, and Iron: While lime, organic matter, and iron may also be present in bricks, they do not typically cause efflorescence. Lime can cause other issues, like lime bloom, which is a different phenomenon. Organic matter and iron do not typically contribute to efflorescence but may affect the color and durability of bricks.
Prevention of Efflorescence:
Good Quality Bricks: Using high-quality, well-fired bricks with low soluble salt content can reduce the likelihood of efflorescence.
Proper Drainage: Ensuring good drainage around the building to prevent water from accumulating and penetrating the bricks.
Sealants and Barriers: Applying water-repellent sealants or vapor barriers to prevent moisture from reaching the bricks.
Efflorescence is generally a cosmetic issue and does not typically affect the structural integrity of the bricks, but it can be unsightly and indicative of moisture problems that may need to be addressed.
