Introduction to rocks with properties and their uses

1. SUBJECT: BUILDING MATERIAL
(3330601)
CH-3 ROCKS & STONES
TAPI DIPLOMA ENGINEERING COLLEGE
Prepared by
Mr. Dhaval Mithaiwala

2.  Classification of Rocks:
Building stones are obtained from
rocks occurring in nature and
classified in three ways.
1. Geological classification
2. Physical classification
3. Chemical classification
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ROCKS & STONES

3.  Igneous rocks: Rocks that are formed by cooling of
Magana (molten or pasty rocky material) are known
as igneous rocks.
Eg: Granite, Basalt and Dolerite etc.
 Sedimentary rocks: these rocks are formed by the
deposition of production of weathering on the pre-
existing rocks.
Examples: gravel, sandstone, limestone, gypsum,
lignite, etc.
Geological Classification

4.  Metamorphic rocks. These rocks are formed by the
change in character of the pre-existing rocks. Igneous
as well as sedimentary rocks are changed in character
when they are subject to great heat and pressure.
Known as metamorphism.
Examples: Quartzite, Schist, Slate, Marble and
Gneisses.
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5.  Stratified Rocks: These rocks
posses planes of stratification or
cleavage and such rocks can be
easily split along these planes.
Ex: Sand stone, Lime stone
 Un stratified rocks: The
structure may be crystalline
granular or compact granular.
Examples: Granite, Basalt, etc.
 Foliated Rocks: These rocks have a
tendency to split up in a definite
direction only.
Ex: Slate
Physical Classification

6.  Siliceous rocks: In these rocks, silica is
predominates. The rocks are hard; durable and
not easily effected by weathering agences.
Ex: Granite, Quartzite, etc.
compact or may be soft.
Ex: slates, Laterites etc.
 Argillaceous Rocks: In these rocks, clay
predominates. The rocks may be dense and
Chemical Classification

7.  Calcareous rocks: In these rocks, calcium
carbonate predominates. The durability to
these rocks will depend upon the constituents
present in surrounding atmosphere.
Ex: Lime Stone, marble etc.
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8. 1.Structure: Stones are used for foundations, walls,
columns, lintels, arches, roofs, floors, damp proof course
etc.
2.Face works. Stones are adopted to give massive
appearance to the structure. Wall are of bricks and facing is
done in stones of desired shades. This is known as
composite masonry.
3.Paving stones: These are used to cover floor of building
of various types such as residential, commercial, industrial
etc. They are also adopted to form paving of roads, foot
paths etc.
Uses of stones:

9. 4.Basic material: Stones are disintegrated and
converted to form a basic material for cement concrete,
morum of roads, calcareous cements, artificial stones,
hallow blocks etc.
5.Misalliances: Stones are also used for (i) ballast for
railways (ii) flux in blast furnace (iii) Blocks in the
construction of bridges, piers, abutments, retaining
walls, light houses, dams etc.
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10. Qualities of a good building stone
 Crushing strength: For a good building stone, the
crushing strength should be greater than l000kg per cm2.
 Appearance: Good building stone should be a uniform
colour, and free from clay holes, spots of other colour
bands etc capable of preserving the colour for longtime.
 Durability: A good building stone should be durable. The
factors like heat and cold alternative wet and dry,
dissolved gases in rain, high wind velocity etc affect the
durability.
 Fracture: For good building stone its fracture should be
sharp, even and clear.
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11.  Hardness: The hardness greater than 17, treated as hard
used in road works. It is between 14 to 17, medium
hardness, less 14 said be poor hardness.
 Percentage wear: For a good building stone, the
percentage wear should be equal to or less then 3 percent.
 Resistance to fire: A good building stone be fire proof.
Sandstone, Argillaceous stone resists fire quite well
 Specific gravity: For a good building stone the specific
gravity should be greater then 8.7 or so.
 Texture: A good building stone should have compact fine
crystalline structure should be free from cavities, cracks or
patches of stuff or loose material. 29

12.  Water absorption: For a good building stone, the
percentage absorption by weight after 24 hours
should not exceed 0.60.
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13. 1) Granite : Igneous un-stratified type of rock, and includes
quartz, felspar, mica, hornblend.
It is closely grained strong rock, with very low porosity.
Resists weathering action. Available in varieties of colours.
Uses : Heavily loaded structures like bridge, abutment, pier,
railway ballast, flooring, cooking platform etc.
2)Basalt : Igneous volcanic rock strong, durable, fine grained.
Available in black, blue, green, greyish colour.
Uses : Road metal, pavement, aggregates, rubble masonry
3) Trap : Igneous rock, properties similar to Basalt.
Uses : Similar to basalt.
STONES WITH PROPERTIES AND USES
OF STONES :

14. 4)Sand stone: Sedimentary rock, containing silica, lime,
magnesia and available in red, green, white, yellowish
colour.
It is strong durable resists weathering action, suitable for
carving work. Free from chlorides mica.
Uses : Walls columns, carving, road metal.
5) Lime stone: Sedimentary rock containing silica, clay,
magnesium carbonate.
It is soft, porous, less durable. Available in white, grey,
pink, red, blew, brown, green, yellowish colours. It is dense
and compact.
Uses : Road metal, railway ballast, steps, walls, blast furnace.
STONES WITH PROPERTIES AND USES
OF STONES :

15. 6)Marble: It is non porous, fine grained, durable, strong
metamorphic rock. Available in pink, blue, white, yellowish,
black, grey, green, colours.
It is easy to dress and suitable for carving work.
Uses : Ornamental works, Dado, floor, statues, columns.
7) Slate: It is metamorphic type rock containing silica and
alumina. It is available in purple to greenish black colours.
Less absorbent and tough.
Uses : Roofing cover, sills, Damp proof courses, partition
walls in sanitary works.
STONES WITH PROPERTIES AND USES
OF STONES :

16. 8) Gneiss: It is metamorphic rock. Splits in thin slabs, easy
to work. It is soft, available in verities of colours.
Uses : Building construction, road metal, pavement,
rough masonry, pitching work, aggregates for concrete.
9) Laterile: It is metamorphic porous soft rock. Poor
weather resistance.
Uses : road metal, rough masonry.
10) Kankar: It is sedimentary type impure lime stone.
Uses: Road metal, hydraulic lime.
11) Kotah: Green or Yellowish..
Uses: Flooring, Kitchen platform, Partition Walls, etc.
STONES WITH PROPERTIES AND USES
OF STONES :

17. Strength : Stone proposed to be used in construction must
be strong enough to bear the incoming loads and stresses.
Strength of stone depends on its compactness. It should have
more specific gravity, strengths of the stones proposed to be
used for piers, abutment, dams must be strong enough.
Durability : Ordinarily the life of a building is estimated as
more than60 years. Hence stones used for its construction
should be durable enough to resists against adverse
weathering actions. Stones should not be porous to absorb
water and then create different problems.
REQUIREMENT OF GOOD
BUILDING STONES

18. Workability : As we have discussed earlier, the stone
should be strong as well as durable. But at the same time too
strong stones creates problems while dressing. All stones
have to be dressed before they are used in construction.
Stones should not take more time for dressing and should not
break while dressing.
Appearance : External faces of the construction forms the
image about the building. Outer surfaces must be pleasing.
This is particularly true when the external surfaces are not
plastered, stones should have uniformity in colour.

19. Fire Resistance : Igneous type compact stones easily break
as they can not resist fire for a longer period. Lime stones
resist fire to some extent. Sand stones, can resist fire for a long
time.
Weather Resistance : Stones disintegrate due to following
reasons :Temperature - Alternative shocks of severe
temperature are not registered by stones and they easily
disintegrate.
Wind velocity : Blast of wind carrying sand particles produce
abrasive actions against the faces of stones. Prolonged effects of
this type damage the stones.

20. Rain : Rain water being acidic may react with the
constituents of the stone causing disintegration. It also create
problems of dampness in the structure.
Vegetation : Roots of vegetation developed and hence are
responsible informing cracks in walls.
Frost : In cold regions when water absorbed by the stone
converts into ice, it expands and damages stones.
Insects : Building stone should not contain insects. Some
insects create holes in the stones and create acidic condition,
stones disintegrate due to chemical reactions with its
ingredients.

21. (1)Structure : Arrangements of minerals in a stone.
Arrangements can be in the form of layers or not.
(2)Hardness / Toughness: It is the capacity of stone to resist
shock.
The value of toughness for an average good stone should
be about 17.
According to Moh's scale hardness is covered between 1
and 10 where1 indicates soft and 10 indicates the hardest
stone (diamond).
CHARACTERISTICS OF
BUILDING STONES:

22. (3)Texture : Texture indicates the arrangements of fine
mineral particles.
• Glassy texture
• Compact texture
• Granular texture
• porphyritic texture
• Porous granular texture
• cellular texture

23. (4) Specific Gravity : For major stone sp. gr. lies between 2
and 3. Stones having more sp. gr are compact and stronger.
(5) Porosity : It indicates proportions of holes in stone. Porous
stones when exposed to atmosphere, absorbs water and
ultimately disintegrates.
(6) Weight : Weight of unit volume of stone depends upon the
sp.gr. of stone.
(7) Durability : Chemical composition, weather resistance,
texture etc. Decide the durability of a stone. A stone
becomes more durable when its natural beds are kept in the
direction perpendicular to the direction of application of
load.

24. (8)Natural Bed of Stone: Natural bed is the layer on which
sedimentary stone was originally deposited.
• The compressive strength of layered stones is always
found to be greater when load is applied in the direction
approximately perpendicular to the beds (layers).
• When load is applied along the direction, parallel to the
direction of beds, it fails by slipping along the bedding
planes.
• When stones are to be used in construction, stones should
be placed in such away that the pressure incoming upon
the stones is always along the direction perpendicular to
the natural bed of stone.

25. (9) Plane of Cleavage: Stones can break easily when
chisel is kept at the joints between two layers. The stone
break along the plane containing layers. Such plane is
called "plane of cleavage of stone".

26. ARTIFICIAL STONES

27. (1)Stone having desired size and shape can be prepared.
(2)No sawing and cutting.
(3)No dressing of stones.
(4)Desired colour can be given to stones
(5)Better weather resisting capacity
(6)Carving is possible.
(7)No natural layers hence stone can be placed in any manner.
(8)Can resist weather changes.
(9)Strength can be increased by providing reinforcements.
(10)Special treatment can be given to the thin layer forming front face.
(11)Beautiful attractive stones can be obtained economically.
Advantages of Artificial stones

28. Types of Artificial Stones
1) Concrete Blocks
2) Terrazzo
3) Hard Concrete Blocks
4) Chemical Stone
5) Reconstructed Stone
6) Artificial marble

29. Comparison of stones with bricks