2. Clay is the result of chemical reactions
with felspar of Igneous rock.
The theoretical formula for clay is Al2O3
2SiO2 2H2O, an alumina-silicate, but none
are that pure and uncontaminated.
Clay products are one of the most
important classes of structural materials.
6. Clay is the most important raw material used for
making bricks, Thus this type of clay is known as
Brick clay.
One of the oldest building material brick continues
to be a most popular and leading construction
material because of being cheap, durable and easy
to handle and work with. Clay bricks are used for
building-up exterior and interior walls, partitions,
piers, footings and other load bearing structures.
7. Clay bricks are commonly used since these are
economical and easily available. The length,
width and height of a brick are interrelated as
below:
Length of brick = 2 × width of brick + thickness
of mortar
Height of brick = width of brick
standard brick:19 × 9 × 9 cm and 19 x 9 x 4 cm
Clay bricks are commonly used since these are
economical and easily available.
10. • Tiles are like bricks reduced thickness. They
can be prepared from selected clay after
molding and drying in kilns.
• These give a very pleasing appearance and
good service properties. Roofing tiles, flooring
tiles, wall tiles and partition tiles are some of
the examples.
14. • These are made by burning the ordinary clay at low
temperature and cooling slowly.
• To check shrinkage, sand and crushed pottery are
mixed with clay.
• This also increases the toughness, hardness and
strength of the ware.
• Earthenware is used for manufacturing drain pipes
and light weight partition walls.
• Earthenware is commonly used in the making of
terra cotta pots, roofing tiles, and other low-fire
ware.
15. China Clay
clays are subdivided as residual and transported
clays. Residual clays, known as Kaolin or China clay,
are formed from the decay of underlying rocks and
are used for making pottery.
16.
17. Stone Wares
• A hard ceramic material resembling porcelain
with a different colour, usually grey or brownish
is made from refractory clay mixed with
crushed pottery, stones and sand burned at
high temperatures and cooled slowly.
• Uses :
• Light sanitary wares, e.g. wash basins, water
closets, etc.
• Flooring tiles and wall tiles in toilets and
kitchens.
18. Porcelain
• White, thin and semi transparent
earthenware prepared from pure plastic clay
felspar and quartz is known as porcelain.
• A high grade ceramic ware having white
color, zero water absorption and glazed
surface
• which can be soft or hard.
21. Terra-cotta
• It is an Italian word, Terra means clay and Cotta
means burnt. Terracotta is refractory clay
product and is used in ornamental parts of
buildings.
USES
• Terra-cotta is used for decorative and
ornamental works.
• Cornices and arches.
• Being fire proof, terracotta is most suitable as
casing for steel columns and beams.
• Porous terracotta is used for sound insulation.
25. • Fireclay is a type of clay that is able to
withstand intense heat.
• It is suitable for making articles which will not
melt, nor even perceptibly soften when
exposed to a high temperature.
• It is used to make fire brick or refractory brick.
• Fireclay consists alumina and silica.
26. • A fire brick or refractory brick is a block of
refractory ceramic material used in lining
furnaces, kilns, fireboxes, and fireplaces.
• A refractory brick is built primarily to
withstand high temperature, but will also
usually have a low thermal conductivity for
greater energy efficiency.
