Transcript Stones

Stones
Outline
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Classification of Source
Quarrying
Dressing
Qualities
Testing
Uses
Types and their Uses
Classification of Rocks
• Geological Classification
– Igneous rocks
• Formed by cooling of molten lava
• Un-stratified rocks
• E.g. Granite, Basalt, Trap
– Sedimentary Rocks
• Formed from weathering deposits (sediments)by wind or water
• Stratified rocks
• Solidified to rocks due to compaction caused intense pressure from
overlaying sediments.
• E.g. Sandstone, Gypsum, Lime stone, peat
– Metamorphic rocks
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Changed from igneous or sedimentary rocks
Foliated ricks
Changed due to intense heat or pressure inside earth
E.g. Marble, Slate, Laterite Gneiss, Quartzite
Classification of Rocks
• Chemical classification
– Siliceous rocks:
• Silica (SiO2) is the major constituent
• Granite, Sandstone
– Argillaceous rocks:
• Clay is the main constituent
• Slate, Laterite
– Calcareous rocks:
• Calcium Carbonate (CaCO3) is the main constituent
• Limestone, marble
Quarrying(Extraction Of Stones)
• The Process of extracting or taking out stones
from rock beds is known as quarrying of stones.
• A Mine is one in which the process is carried
on.
• Methods Of Quarrying
– Digging or excavating, heating, wedging
• For soft rocks like limestone, marble
– Blasting-blasting rocks with explosives
• For hard dense rocks like granite, basalt
Dressing Of Stones
• Stones obtained from quarrying have rough
surface
• Dressing is the process of cutting the stones
into regular shape and size with the required
finished surface.
• Purpose
– Suitable size
– Regular shape and pleasing appearance
– Proper bedding for stone masonry
Qualities of A Good stone
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Crushing strength >100 N/sq.mm
Uniform color
Fine crystalline structure, strong and should be durable
Easy to carve and dress
Building stone should be sharp and clear
Stones used in road work must be hard enough
Wear and tear < 3%
Wear and tear = 3% (tolerable)
Wear and tear >3% (not satisfactory)
• Specific gravity >2.7
• Should not absorb water more than 0.6% by weight
• Acid resistant, fire resitant
Testing Of Stones(Exam Point Of View)
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Hardness Test: tested by pen knife which will not produce scratch
Impact Test(Toughness): tested by impact test machine.
Test for crushing strength:
crushing strength= max load at failure
Area of bearing face
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Microscopic Test: to study properties like Mineral constitution, texture,
average grain size etc
Attrition/Abrasion Test: to test % of wear of stones in Deval’s attritions test.
% wear=(Loss in weight/initial weight) *100
Smith’s Test: to find presence of earthly matter in stone
(broken pieces of stone shaken with water vigorously)
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Electrical Resistance Test: resistance of stones is measured from its water
absorption capacity (as wet stones have less resistance)
Crystallization Test: immersed in a solution of Sod. Sulphate and dried in hot
air. Diff in weight if any is recorded and that determines the durability of
stones
Acid test: corners of the stone become roundish and loose when kept
immersed in HCl or H2SO4 for a long period. This test is carried out in order to
determine whether the stone can be used in smoky atmosphere
Fire Resistance Test: to find its fire resistance, test for the amount of Calcium
Carbonate present (Add H2SO4 and you get bubbles)
TO REMEMBER THESE POINTS – MASE HIT CAFÉ (E no use)
Basic Use
Stone is used in two fundamentally different ways in buildings:
• It may be laid in mortar, much like bricks or concrete blocks, to make walls, arches,
and vaults, a method of construction referred to as stone masonry.
• It may be mechanically attached to the structural frame or walls of a building as a
facing, called stone cladding.
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As known it is used for construction like construction of walls, columns, arches,
roofs, floors etc
For foundation of buildings, damp proof courses etc.
Hard stones used for pavements and roads.
As a basic material in concrete manufacturing.
As flux in blast furnaces, blocks in construction of bridges, piers etc
Types Of Building Stones
GRANITE:
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Granite is the igneous rock most commonly quarried for construction in North America.
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Granite is nonporous, hard, strong, and durable, the most nearly permanent of building stones
USES
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Granite has been extensively used as a dimension stone and as flooring tiles in public and commercial
buildings and monuments.
Life-size elephant and other creatures
carved in granite; Mahabalipuram.
Polished granite is also a popular choice
for kitchen countertops due to its high durability
and aesthetic qualities
LIMESTONE
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Limestone is one of the two principal sedimentary rock types used in construction.
Limestone may be composed either of calcium carbonate (oolitic limestone) or of a mixture of calcium and
magnesium carbonates (dolomitic limestone).
USES
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Limestone is very common in architecture, especially in Europe and North America.
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Manufacture of Cement.
DO YOU KNOW
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So many buildings in Kingston, Canada were constructed from it that it is nicknamed the 'Limestone City'.
SANDSTONE
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Sandstone is the second major sedimentary rock type used in building
construction.
Sandstone was formed in ancient times from deposits of quartz sand (silicon
dioxide).
USES
• Flooring: Sandstones are mainly used in paving, flooring, roofing etc. This is very
strong that makes it perfect material for flooring.
• Resistant to Corrosion and weathering.
• The different shades and patterns of sandstone make garden pavement gorgeous.
Sandstone composed mainly of quartz grains
QUARTZITE
• Quartzite is a hard metamorphic rock which was originally sandstone.
• Sandstone is converted into quartzite through heating and pressure.
• Pure quartzite is usually white to grey, though quartzites often occur in
various shades of pink and red due to varying amounts of iron oxide
(Fe2O3).
USES
• Quartzite is a decorative stone and may be used to cover walls, as roofing
tiles, as flooring, and stair steps.
• Crushed quartzite is sometimes used in road construction .
Quartzite mine in British Columbia,
Canada
Quartzite with shades
of Red and Pink due to
amounts of iron oxide
(Fe2O3).
SLATE
• Slate is one of the two metamorphic stone groups utilized in construction.
• Slate was formed from clay.
• It is a dense and hard stone.
USES
• Slate can be made into roofing slates, also called roofing shingles
• Slate is particularly suitable as a roofing material as it has an extremely
low water absorption index of less than 0.4%.
• Slate tiles are often used for interior and exterior flooring, stairs, walkways
and wall cladding.
Slate roof.
Buildings with slate
roofs.
MARBLE
• Marble is the second of the major metamorphic rock groups.
• In its true geologic form it is a recrystallized form of limestone.
• It is easily carved and polished and occurs in white, black, and nearly every
colour, often with beautiful patterns of veining.
USES
• Mainly used for Flooring.
• Finely ground marble or calcium carbonate powder is a component
in paper, and in consumer products such as toothpaste, plastics,
and paints.
• Also for interior decorations.
Different Textures Of Marble
Marbles Obtained Form the
site
Marble Stone
Marbles Used In Construction
The Taj Mahal is made of
marble.
Ancient marble columns
in a prayer hall
CHALK
• Chalk is a soft, white, porous sedimentary
rock, a form of limestone composed of
the mineral calcite.
• Calcite is calcium carbonate or CaCO3. It
forms under relatively deep marine
conditions
USES
Chalk is used to make quicklime and
slaked lime, mainly used as lime mortar
in buildings.
LATERITE
• Laterites are soil types rich
in iron and aluminium, formed in hot and
wet tropical areas. Nearly all laterites are
rusty-red because of iron oxides.
• They develop by intensive and longlasting weathering of the underlying parent
rock.
USES
• Used in wall Construction and
rough stone masonry work.
GRAVEL
• Gravel is a rock that is of a specific particle size range. Specifically, it is any
loose rock that is larger than 2 mm (0.079 in) in its smallest dimension .
• The next smaller size class in geology is sand.
USES
• Gravel is an important commercial product, with a number of applications.
Many roadways are surfaced with gravel, especially in rural areas where
there is little traffic.
• Both sand and small gravel are also important for the manufacture
of concrete.