Clay products
Clay products are one of the most important classes of structural materials. The raw materials used in their manufacture are clay blended with quartz, sand, chamatte (refractory clay burned at1000–1400°C and crushed), slag, sawdust and pulverized coal. Structural clay products or building ceramics are basically fabricated by moulding, drying and burning a clay mass.
Bulk specific gravity of clay brick ranges from 1.6 to 2.5. According to the method of manufacture and structure, bricks, tiles, pipes, terracotta, earthenwares, stonewares, porcelain, and majolica are well recognized and employed in building construction.
Clay bricks have pleasing appearance, strength and durability whereas clay tiles
used for light-weight partition walls and floors possess high strength and resistance to fire. Clay pipes on account of their durability, strength, lightness and cheapness are successfully used in sewers, drains and conduits.
* Polycrystalline materials and products formed by baking natural clays and mineral
admixtures at a high temperature and also by sintering the oxides of various metals and
other high melting-point inorganic substances.
Higher the bulk specific gravity, the stronger is the clay product. This rule does not hold good for vitrified products since the specific gravity of clay decreases as vitrification advances.