What is Rock A rock is a naturally occurring solid. It is made of minerals (which are crystalline), or other mineral-like substances. The Earth's outer solid layer, the lithosphere, is made of rock. That means the Earth's crust is made of rock. Mechanical Behavior Of rocks Elasticity of Rock Specific gravity stress Strain Permeability Porosity Strength

1. Mohammad Waqas (19CH18)
 Presentation Topic: Mechanical
Behavior of Rock/Stone
 Subject: Engineering Materials
 Date: 23/7/2020
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2. What is Rock
 A rock is a naturally occurring solid. It is made of minerals (which
are crystalline), or other mineral-like substances. The Earth's outer
solid layer, the lithosphere, is made of rock. That means the Earth's
crust is made of rock.
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 Rocks

3. Mechanical Properties of Rocks
Elasticity of Rock
Specific gravity
stress
Strain
Permeability
Porosity
Strength
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4. Elasticity Of Rock:
 Some of the deformation of rock under stress will be recovered when the load is
recoverable deformation is called elastic and the non recoverable part is called
plastic deformation .plastic behavior involves continuous deformation after some
critical value of stress has been reached
SPECIFIC GRAVITY
 Specific gravity is the ratio of the mass (weight) of a rock to the mass of the same
volume of water
 Water has a density of 1.0g/cm3 so the numeric value of specific gravity is the
ratio. It has no unit
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5. Stress
 Stress is the force per unit area acting on a plane at any point within a material .there
are three types of forces
 Compressive stress: equal forces that act towards a point from opposite direction
 Tensile stress: equal forces that pull away from each other
 Shear stress: equal forces that act in opposite directions but off set from each other
to act a couple
Strain
 The application of stress to a material causes it to deform .The amount of
deformation is called strain
 Axial Strain: deformation along the direction of loading
 Lateral Strain: the lateral extension perpendicular to the direction of along
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6. PERMEABILITY
 Is the capacity of porous medium to transmit water or liquid i.e relative easy to flow
of a liquid under unequal preasure
 It a factor how a rock will act as a source of water for a well
 A rock permeable when the rock has got many connected pore space
POrOSITY
 Porosity is an index the amount of the groundwater then can be stored in the
saturated formation
 Porosity is the ratio between the total voids or pores of particular rocks to the total
volume of same rock
 It is usually expressed in percentage of the bulk volume of the rocks
 There are two types of porosity
 Primary porosity (before the formation)
 Secondary porosity (after the formation)
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7. STRENTH
 The strength of a material is defined as the load under which
the material cracked and disintegrated
 The experimental definition of strength is determined by
increasing the load observing at the point at which the first
crack appeared
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8. DIFFERENT TYPES OF STONES USED IN
CONSTRUCTION
BASALT AND TRAP
 GRANITE
MARBLE
SLATE
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9.  BASALT AND TRAP
 The structure is medium to fine grained and
compact. Their colour varies from dark gray to
black. These are igneous rocks. They are used
as road metals. They are also used for rubble
masonry works for bridge piers, river walls and
dams.
 GRANITE
Granites are also igneous rocks. The colour
varies from light gray to pink. The structure is
crystalline, They take polish well. They are
hard durable. They are used primarily for
bridge piers, river walls, and for dams. They
are used as kerbs
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10. MARBLE
 This is a metamorphic rock. It can take
good polish. It is available in different
pleasing colours like white and pink. It is
used for facing and ornamental works. It
is used for columns, flooring, steps etc.
 SLATE
 These are metamorphic rocks. They are composed of
quartz, mica and clay minerals. The structure is fine
grained. They split along the planes of original bedding
easily. The colour varies from dark gray, greenish gray,
purple gray to black. They are used as roofing tiles, slabs,
pavements etc.
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 References
 https://www.slideshare.net/mobile/pramodgpram
od/mechanical-characters-of-rock
 https://www.britannica.com/science/rock-
geology/Mechanical-properties