INTRODUCTION TO CONSTRUCTION MATERIALS.PPT(PDF)

1. CHAPTER -1
JIMMA UNIVERSITY
JIMMA INSTITUTE OF TECHNOLOGY
Faculty of Civil and Environmental Engineering
Department of Civil Engineering
INTRODUCTION TO BUILDING MATERIALS
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Construction Materials (Ceng-3111)
By: Frikot M.(Engr.)

2. General out line
➢Classification of Engineering(construction) Material.
➢Mechanical Properties of Materials.
➢Nature and Performance of Materials Under Load.
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3. Classification of Engineering(construction)Material.
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Defn; Construction Material is any material which is used in
construction industry. Examples: cement, soil, aggregates, asphalt,
etc

4. Mechanical Properties of Material(Static
stress-strain properties)
▪ Application of forces on solid bodies under equilibrium results
in the development of internal resisting forces and the body
undergoes deformations to a varying degree.
✓ Internal forces are called stresses.
✓ Internal deformations are called strains.
▪ These properties are concerned with the following properties
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5. Tensile strength (TS)
▪ It is the ability of a material to withstand tensile ( stretching )
loads without breaking. Example the stretching rod.
▪ Strength: is the ability of a material to resist applied forces
without fracturing.
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6. Toughness
▪ It is the ability of the materials to withstand bending or
▪ It is the application of shear stresses without fracture.
▪ So the rubbers and most plastic materials do not shatter,
therefore they are tough.
▪ For example, if a rod is made of high-carbon steel then it will
be bend without breaking under the impact of the hammer.
▪ If a rod is made of glass then it will broken by impact loading.
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7. Toughness (CON’T)
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8. Malleability
▪ It is the capacity of material to withstand
deformation under compression without rupture or,
▪ The malleable material allows a useful amount of
plastic deformation to occur under compressive
loading before fracture occurs.
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9. Hardness
▪ It is the ability of a material to withstand scratching
(abrasion) or indentation by another hard body.
▪ It is an indication of the wear resistance of the material.
▪ For example, a hardened steel ball being pressed first into a
hard material and then into a soft material by the same load.
▪ As it is seen below the ball makes a small indentation in the
hard material and deeper impression in the softer material.
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10. Hardness(CON’T)
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11. Ductility(CON’T)
▪ It refer to the capacity of materials to undergo
deformation under tension without rupture.
▪ Example, in wire drawing , tube drawing operation
e.t.c
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12. Stiffness
▪ It is the measure of a material's ability not to deflect under an
applied load.
▪ For example, consider steel and cast iron(more rigid).
▪ Steel is very strong than the cast iron ,but cast iron is preferred for
machine beds and frames.
▪ This is because it is more rigid and less likely to deflect with
consequent loss of alignment and accuracy.
 material which is rigid is not necessarily strong. Example see the
following fig(a and b)
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13. Stiffness(con’t)
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14. Brittleness
▪ It is the property of a material that shows little or no plastic
deformation before fracture when a force is applied.
▪ Also it is usually said as the opposite of ductility and
malleability.
▪ For example concrete is brittle material.
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15. Elasticity
▪ It is the ability of a material to deform under load and return to its
original size and shape when the load is removed.
▪ If it is made from an elastic material , it will be the same length
before and after the load is applied, despite the fact that it will be
longer while the load is being applied.
▪ All materials posses elasticity to some degree and each has its
own elastic limits.
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16. Elasticity
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17. Plasticity
▪ It is the state of a material which has been loaded beyond its
elastic limit so as to cause the material to deform permanently.
▪ This property is the opposite of elasticity.
▪ The ductility and malleability are particular causes .
▪ Under such conditions the material takes a permanent set and
will not return to its original size and shape when the load is
removed.
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18. Plasticity
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19. Nature and Performance of Materials Under Load.
▪ Here we are going to see the stress-strain property of materials.
▪ Stress is the ratio of applied force to the cross-sectional area or the
product of young’s modulus and strain.
▪ Strain is the ratio of extension to original length.
▪ The term that determines the performance of material under load are:
 Yield strength
 Ultimate strength and
 Breaking strength
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20. Performance of Materials(con’t)
▪ Yield strength: the stress at which the yield is initiated.
▪ Ultimate strength: the stress corresponding to the maximum
load applied to the specimen.
▪ Breaking strength: the Stress corresponding to the rupture.
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21. Performance of Materials(con’t)
▪ Now let as see the stress-strain performance of
1. Ductile materials, such as structural steel and other alloys of
metals.
2. Brittle materials such as cast iron, glass, stone and concrete.
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22. Typical stress-strain curve for annealed mild
steel.
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23. Typical stress-strain curve of a light alloy.
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24. Typical stress-strain curve of grey cast iron.
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25. Typical stress-strain curve of brittle materials
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26. Check your progress
▪ Do you understand the classification of construction
materials ?
▪ Would you explain the mechanical properties of
engineering materials?
▪ Do you understand the performance of materials under
load? That is the stress-strain properties of materials under
load.
▪ Calculate the modulus of elasticity for a material which
produces the following data when undergoing test:
Applied load = 35.7 kN,
▪ Cross-sectional area = 25mm2, Gauge length = 28 mm,
Extension = 0.2 mm.
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