011 1 Materials&Engineering

8/14/2019 011 1 Materials&Engineering

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Materials of Construction-Materials and Engineering 1

MATERIALS

AND

ENGINEERING

Chapter 1


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What is Civil Engineering?

"...the art of directing the great sources of power in

nature for the use and convenience of man*

* Institution of Civil Engineers, www.ice.org.


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Engineering Structures-

Requirements

Engineering structures have to be-SSE;

Safe,

Servicable,

Economical

These depend on a sound knowledge of

materials.


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Engineering Knowledge

The engineer should know:

1. how to selectthe most appropriate materials,

2. properties of materials, including mechanical propertiesand behavior under different environmental conditions,

3. the standard specifications relevant with selectedmaterials,

4. the most appropriate testing method for measuring thequality of materials, and the procedures for inspecting theperformance of the materials.


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Selection of Materials-

Considerations

-Types and properties of the available materials,

-Initial and maintenance costs of the available

materials,

-Methods of preparation or manufacture of

materials,

-Methods of testing and inspection of thematerials according to relevant specifications.


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Concrete Asphalt

Initial Cost +

Useful Life +

Frequency of Repair +

Cost of Repair +

Comfortability +

Example: Comparison of concretepavement vs. asphalt pavement


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3. Ceramics : (mainly aluminosilicates formed

by mixed bonding, covalent and ionic)

A. Structural clay products (bricks, tiles, pipes)B. Porcelains4. Composite Materials :

A.Natural (agglomerates)

B.Artificial (Portland cement concrete)

Internal Structure & Chemical

Composition Classification


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5. Reinforced Composite Materials :

(reinforced concrete, reinforced plastics)

One of the most important task of an

engineer is to select the most suitable

material for a given civil engineeringstructure.

Internal Structure & Chemical

Composition Classification


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PROPERTIES OF MATERIALS

1)Mechanical

-Strength

Compression

Tension

Shear

Flexure

Fatigue

-Elasticity, elastic moduli (E, G, K)

-Stress-strain relationship

-Plasticity, flow

-Ductility, brittleness

-Hardness, wear resistance


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2) Physical

-Dimensions, shape, surface texture

-Density or specific gravity

-Porosity-Moisture content, absorption

-Macrostructure

-Microstructure

3) Chem ical

-Oxide or compound composition

-Acidity, alkalinity

-Resistance to corrosion, sulfates, acids, etc.


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4) Phys ico-chemic al

-Water-absorptive or water-repellent action

-Shrinkage, swelling

5) Therm al

-Specific heat

-Expansion

-Conductivity

6) Electr ical

-Conductivity

-Galvanic action


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7) Acoust ical

Sound transmission

Sound reflection

8) Optic al

Color

Light transmission

Light reflection


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Mechanical Properties of

Engineering Materials

Mechanical Properties define the behavior

of the materials under various types of

loads.

The mechanical properties are affected

mainly by the physical, chemical andthermal propertiesof the material.


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Durability of Engineering

Materials

Durability is the ability of a material to resist

weathering action, chemical attack, corrosion,

abrasion, and other destructive forces duringthe useful life of the structure.

The durability of materials is affected by their

physical, chemical, physico-chemical, thermal,electrical and mechanical properties.


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Standard Specifications

A specificationis a written detailed description of

something, or of a plan or proposal for that

something.

Various organizations have established

definitions, testing procedures and evaluation

of test results of materials. These descriptionsare presented as standards.


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Standardization Bodies

Relevant Standards

Institutes (Agencies) Relevant Standards orSpecifications

Turkish Standards Institute(TSE)

Turkish Standards (TS)

American Society for Testingand Materials (ASTM)

ASTM Specifications

American Concrete Institute(ACI)

ACI Specifications orRecommendations

International StandardsOrganization (ISO)

ISO Standards

European Committee forStandardization (CEN)

European Norms (EN)


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Standards - Advantages

Standards,

- reduce misunderstandings between the producer andthe consumer,

- help the manufacturer to produce more uniform andcheaper products,

- allow the designers to select a materials withreasonable assurance of obtaining,

- provide testing procedures for material characteristicsor to evaluate the test results for accepting or rejectingthe materials.


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Materials Testing

Materials may show variations in their

characteristics and performance.

Therefore, testing and inspection of qualityand performance of a material are of vital

importance.


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References

* See course outline for references.

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011 1 Materials&Engineering