Stones

Outline

• 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• 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• 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)

• 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

• 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)

• 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 UseStone 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.

• 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:• Granite is the igneous rock most commonly quarried for construction in North America.• Granite is nonporous, hard, strong, and durable, the most nearly permanent of building stonesUSES• 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• 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• Limestone is very common in architecture, especially in Europe and North America.• Manufacture of Cement.

DO YOU KNOW • So many buildings in Kingston, Canada were constructed from it that it is nicknamed the 'Limestone City'.

SANDSTONE• 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

The Taj Mahal is made of marble.

Ancient marble columns in a prayer hall

Marbles Used In Construction

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

USESChalk 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 long-lasting 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.