STONES, BRICKS AND CLAY PRODUCTS
INTRODUCTION
Stones, Bricks and clay products are inert materials used in building construction,
roads, dockyards, airfields etc. Stone is a natural material of construction and it is
in use since prehistoric days. Bricks are blocks of tempered day moulded to
suitable shape and sizes, used for most of the building works. Sometime bricks
are used as substitute for stone, where stone is not cheaply available. Tile is one
of the clay product used for roof covering and paving. The focus of this unit will
be on stone, bricks and tile and we will be studying their classification, uses,
characteristics, manufacturing and tests.
Objectives
After studying this unit, you should be able to
• classify rocks, bricks and tiles,
• describe uses of stones, bricks and tiles
• explain characteristics of good building stones, bricks and tiles,
• appreciate the importance of tests of stones and bricks, and
• distinguish between stone and brick as a material of construction.
STONE
Stone is a natural material of construction and is obtained from quarries. It has
been used for constructing different components of buildings like foundations,
walls, lintels, floors, roofs, bridges, weirs, dams etc.
Stones that are used for construction of structures are known as building stones.
Uses of Stones
Stones are extensively used for the following purposes :
(i) It is used as stones ballast for railway track, for road construction, for
preparing cement concrete required for foundations, flooring, hollow
and solid blocks, artificial stones and reinforced cement concrete.
(ii) It is used as a crushed stone (stone dust) as a substitute for sand.
(iii) It is used as blocks in the construction of buildings, lintels, arches,
walls, columns, abutments and piers of bridges, in weirs and in dams
etc.
(iv) It is used as blocks and slabs for face work of buildings requiring
architectural treatments.
(v) It is used as thin slabs for roofing and for flooring buildings and
pavements.
(vi) It is used as limestone in the manufacture of lime, cement and in
various other chemical processes.
(vii) Thin slabs of impervious stones are used for laying Damp Proof
Course in buildings.
(viii) Base material for water and sewage filters, in case of waterworks and
sewage treatment plants.
(ix) Stone may be used to give massive and pleasing appearance.
(x) Lime stone is also used as a flux in the blast furnaces.
Limitations in Uses of Stones
Stones are gradually losing their Universal use as a building material
because of following reasons :
(i) Important buildings these days are being constructed of steel or RCC,
because of their being less bulky, stronger and more durable.
(ii) Strength of structures made of stones cannot be so rationally analysed
as of those made with steel and RCC.
(iii) Suitable, durable and more easily workable alternatives materials are
now available.
(iv) Cast stone, sand faced rusticated bricks, furnace ware etc. can be
given architectural treatment more easily and have, therefore,
overshadowed the use of stones.
(v) Stones are not cheaply and conveniently available in the plains.
(vi) Bringing the stone to required shape and size is time-consuming and
results in slow pace of construction.
Classification of Stones
Stones are obtained from rocks. A rock forms portion of earth’s crust having no
definite shape or chemical composition. It is usually a mixture of two or more
minerals and is not homogeneous.
Rocks from which stones can be had for building purposes are classified in the
three different ways :
(i) Geologically
(ii) Physically
(iii) Chemically
Classification based on hardness of the stone are :
Geological Classification
This classification depends upon how the rock was originally formed.
Geologists classify rocks into three main categories:
Igneous Rocks
Inner layers of earth are at such high temperatures that masses of
silicates melt. This molten mass, known as magma, is forced up.
Magma solidifies into rocks when it reaches the surface of earth and
forms basalts and traps. If, however, the magma solidifies before
reaching the surface of earth it forms solid crystalline rock known as
Granite. Basalt, Trap and Granite are Igneous rocks.
Sedimentary Rocks
Surface of earth is subjected to the destructive action of rain, frost,
winds and chemical actions. These destructive agents break up the
surface of earth which gets further broken up when carried down by
rains and rivers. In the journey of river from mountains to sea the
velocity goes on decreasing as the river moves further.
Uses of Stones
Stones are extensively used for the following purposes :
(i) It is used as stones ballast for railway track, for road construction, for
preparing cement concrete required for foundations, flooring, hollow
and solid blocks, artificial stones and reinforced cement concrete.
(ii) It is used as a crushed stone (stone dust) as a substitute for sand.
(iii) It is used as blocks in the construction of buildings, lintels, arches,
walls, columns, abutments and piers of bridges, in weirs and in dams
etc.
(iv) It is used as blocks and slabs for face work of buildings requiring
architectural treatments.
(v) It is used as thin slabs for roofing and for flooring buildings and
pavements.
(vi) It is used as limestone in the manufacture of lime, cement and in
various other chemical processes.
(vii) Thin slabs of impervious stones are used for laying Damp Proof
Course in buildings.
(viii) Base material for water and sewage filters, in case of waterworks and
sewage treatment plants.
(ix) Stone may be used to give massive and pleasing appearance.
(x) Lime stone is also used as a flux in the blast furnaces.
Limitations in Uses of Stones
Stones are gradually losing their Universal use as a building material
because of following reasons :
(i) Important buildings these days are being constructed of steel or RCC,
because of their being less bulky, stronger and more durable.
(ii) Strength of structures made of stones cannot be so rationally analysed
as of those made with steel and RCC.
(iii) Suitable, durable and more easily workable alternatives materials are
now available.
(iv) Cast stone, sand faced rusticated bricks, furnace ware etc. can be
given architectural treatment more easily and have, therefore,
overshadowed the use of stones.
(v) Stones are not cheaply and conveniently available in the plains.
(vi) Bringing the stone to required shape and size is time-consuming and
results in slow pace of construction.
Classification of Stones
Stones are obtained from rocks. A rock forms portion of earth’s crust having no
definite shape or chemical composition. It is usually a mixture of two or more
minerals and is not homogeneous.
Rocks from which stones can be had for building purposes are classified in the
three different ways :
(i) Geologically
(ii) Physically
(iii) Chemically
Classification based on hardness of the stone are :
Geological Classification
This classification depends upon how the rock was originally formed.
Geologists classify rocks into three main categories:
Igneous Rocks
Inner layers of earth are at such high temperatures that masses of
silicates melt. This molten mass, known as magma, is forced up.
Magma solidifies into rocks when it reaches the surface of earth and
forms basalts and traps. If, however, the magma solidifies before
reaching the surface of earth it forms solid crystalline rock known as
Granite. Basalt, Trap and Granite are Igneous rocks.
Sedimentary Rocks
Surface of earth is subjected to the destructive action of rain, frost,
winds and chemical actions. These destructive agents break up the
surface of earth which gets further broken up when carried down by
rains and rivers. In the journey of river from mountains to sea the
velocity goes on decreasing as the river moves further.
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