Application of Construction materials
Concrete
Concrete is used in construction areas. it is
mixture of Portland cement & water with a definite quantity of sand or
stone. This mixture is called cement paste. The strength of cement paste
depends on the relative quantity or proportion of water & cement.
Timber
Timber is used in construction and furniture works.
It is used in high class joinery & general joinery. It is also used in
structural grade .there are some common applications of timber for example
- Windows, doors & stairs
- Architectural structures
- Craft items & turnery
- Framing
- External structures & landscaping,
- Fitting & trims
Steel
- Steel is used in construction areas for example
- Reinforced concrete
- Bridge deck plates
- Educations & hospitals building
- Offices & tunnels
- Bridges, station & buildings
Specification of construction materials (concrete, timber, steel) regarding their performance in use
Specification of construction materials
Steel
The suitable specification of steel depends on
application areas. If we consider for construction application, the main factor
of steel is its strength. There are so many types of grades of steel.
There are so many types of ASTM specification.
For example
For hot rolled product – ASTM A36/A36M
For hot rolled product – ASTM A36/A36M
For sheet – ASTM 606, for
bolt, nut & washers- ASTM A307
Concrete
The specification of concrete for construction field
should be as per standard
IST EN206-1, this standard gives the whole
information about specification, production & application of concrete in
construction areas.
Timber
Timbers are widely using these days in construction
areas; there is some required specification for timber.
For example
- Moisture: moisture should be less than 20%.
- Grades: Timer grades as per standard BS EN 14081, timbers are graded according to some properties like Fissures, knots & slope of grain against the allowable limit.
- Strength: it is property of timber to apply resistance against yielding under the action of different type of loads.
- Dimension & tolerances: it should be as per requirement and design.
Stress-strain
diagram of steel and concrete
Behavior of steel structural under load
From stress strain diagram, we can find the below
information.
Point A is called as proportionality limit, up to
this point hook’s law will be followed and stress will be directional
proportional to strain.
Point B - Elastic
limit, up to this point the deformation will be elastic.
Point C – Ultimate
stress, it is the maximum value of stress in stress – strain diagram.
Point D- it is the fracture
point, up to this point the material will have only elastic & plastic
deformation ,but at this point fracture or rupture take place.
So we may know that
behavior of steel under load will be as ductile material because there is
elastic and plastic deformation before rupture.
Behavior of concrete under load
In case of concrete as
we can see the diagram
There is no plastic
elongation under load before fracture, so it is as brittle material.
Stress and strain diagram for Timber
Timber is also well known brittle material so its
stress & strain diagram will be same as above, there will be no plastic
elongation before rupture, and its stress and strain diagram will be same as of
concrete.
Conclusion
Before selection any material we have to know that
application area , that means where we are going to use and properties are
required over there.
So before selection any material we should know all the details required by application areas.
For example in case of construction of this house we
should know that it requires insulating material in order to reduce the loss of
heat. It requires ventilation system and we have also information
about the required capacity of ventilation system so accordingly we can quote
the materials.
What types of load are present and what is the
atmospheric condition we can select the materials.
So in one sentence we can say the selection of
materials is governed by demand and application areas.
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