Transcript Document

CHAPTER I
Testing of Material
Properties
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1.1 Significance of testing materials
The testing of materials may be performed with one
of the three points below:
(1) to supply routine information on the quality of a
product- commercial or control testing,
(2) to develop new or better information on known
materials or to develop new materialsmaterials research,
(3) to obtain accurate measures of fundamental
properties of materials- scientific measurement.
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Commercial testing
Commercial testing is concerned with;
 checking the acceptability of materials with respect
to the specifications,
 control of production.
Generally, the type of the test has been specified,
standard procedures are used, and the object is to
determine whether the properties of a material fall
within the required limits.
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Materials research
Materials research is done in order to;
(1) obtain new understanding of known materials,
(2) discover the properties of new materials,
(3) develop meaningful standards of quality or
test procedures.
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Scientific testing
Scientific testing is the accumulation of orderly
and reliable informations on the fundamental
and useful properties of materials.
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What is the difference between
experiments and tests?
Experimentation means that the outcome is
uncertain, that new insights are to be
gained.
Testing is a more defined procedure, with the
limits and results are clear.
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Materials testing may be carried out on
1. Full size structures, members, or parts,
2. Models of structures, members, or parts,
3. Specimens cut from finished parts,
4. Specimens of raw or processed materials,
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Destructive testing vs
Non-destructive testing
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Destructive testing is carried out until the
specimen’s failure. These tests are generally
much easier to carry out, yield more
information and are easier to interpret than
non-destructive testing
Non-destructive testing is the type of testing
that does not destroy the test object. It is vital
when the material in question is still in
service.
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Field Tests vs Laboratory Tests
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Field tests usually lack the precision of
similar tests conducted in the laboratory,
However, some tests cannot be made in
the laboratory and others cannot be
made in the field.
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Precision & Accuracy
Precision: repeatability of a measurement
Accuracy: its closeness to the true value
Exp/ If an instrument consistently gives nearly
identical but wrong readings- precise but
inaccurate
If readings vary considerably but do center about
the true value- accurate but imprecise
Test results should be both precise and accurate!
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1.2 Standard Specifications &
Standardizing Agencies
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Specification: A precise statement of a set of
requirements, to be satisfied by a material,
product, system or service. It is desirable that the
requirements, together with their limits, should be
expressed numerically in appropriate units.
A standard specification for a material is the result
of agreement between those concerned in a
particular field and involves acceptance for use by
participating agencies.
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Standardizing Agencies &
Relevant Standards
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Turkish Standards Institute (TSE)-Turkish
Standards (TS) http://www.tse.org.tr/
American Society for Testing and Materials
(ASTM)- ASTM Specifications
http://www.astm.org
International Standards Organization (ISO)ISO Standards http://www.iso.org
European Commitee for Standardization
(CEN)- European Norms (EN)
http://www.cen.eu
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1.3 Properties of Engineering
Materials
Principal materials used in construction are;
 metals,
 woods,
 portland cement concretes,
 bituminous mixtures,
 clay products,
 masonry materials,
 plastics.
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Engineering Materials
The principal function of these materials is
to develop
 Strength,
 Rigidity,
 Durability,
adequate to the service for which they are
intended.
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An important property- Strength
The major work of the ordinary materials
testing laboratory has to do with mechanical
properties. – mechanical testing
A first requirement of any engineering material
is adequate strength
The term testing machine refers to a machine
for applying loads.
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Properties of engineering
materials-1
Class
Property
General
Density or specific gravity,
Porosity
Moisture content
Macrostucture
Microstructure
Chemical Oxide or compound composition
Acidity or alkalinity
Resistance to corrosion or weathering
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Properties of engineering
materials-2
Class
Physicochemical
Property
Water-absorptive or water-repellent action
Shrinkage and swell due to moisture
changes
Mechanical Strength: Tension, compression, shear
and flexure
Stiffness
Elasticity, plasticity
Ductility, brittleness
Hardness, wear resistance
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Properties of engineering
materials-3
Class
Thermal
Electrical and
magnetic
Property
Specific heat
Expansion
Conductivity
Conductivity
Magnetic permeability
Galvanic action
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Properties of engineering
materials-4
Class
Acoustical
Optical
Sound transmission
Sound reflection
Color
Light transmission
Light reflection
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TASK
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Visit the Civil Engineering laboratory,
notice where the general equipment is
located.
Learn the instruction of the operation of
the compressive strength testing
machine.
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References
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“The Testing of Engineering Materials,” H.E.
Davis, G.E. Troxell and G.F.W. Hauck, McGrawHill Book Company, 1964.
“The Science and Technology of Civil Engineering
Materials,’’ J. F. Young; S. Mindess; R.J. Gray and
A. Bentur, Prentice Hall, 1998.
“Civil Engineering Materials,” S. Somayaji,
Prentice Hall, NJ, 1995.
“Design and Control of Concrete Mixtures”,
Portland Cement Association, USA, 1979.
www.wikipedia.org
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