12/10/2016 1 CIV-E1010 Building Materials Technology Lecture 01 – Mechanical and non- mechanical properties of building materials 12.09.2016 CIV-E1010 Building Materials Technology Fahim Al-Neshawy 2 • Time: 12.09 – 20.10.2016 • Lectures: Mondays and Tuesdays 14:00 to 16:00 • Exercises: Thursdays 8:30 to 10:00 • Status of the course: Master degree course • Academic Year, Period: Autumn 2016 (Period I) • Location: Otaniemi / Lecture hall R2 • Language of Instruction: English • Course Website: https://mycourses.aalto.fi/course/view.php?id=12977 Basic information CIV-E1010 Building Materials Technology Fahim Al-Neshawy 3 Instructors’ contact information: • Prof. Jussi Leveinen (Geomaterials) • Prof. Jouni Punkki (Cement Based Materials) • Teacher: D.Sc. Fahim Al-Neshawy • Course assistant: Kirsi Heikkinen • E-mail: [email protected]Basic information CIV-E1010 Building Materials Technology Fahim Al-Neshawy 4 1. Knowledge: will be able to learn basic theory about main building- and construction materials: • material composition / Properties • applications in buildings and structures 2. Skills: be able to make right and well-founded choice of materials 3. General competence: understand how properties of materials can be related to the characteristics of the material. Learning outcomes
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Lecture 01 – Mechanical and non- mechanical properties of ... · • mud brick, • masonry blocks • Timber and terra cotta 100 B.C. – 400 AD • Stone sand, gravel • Marble
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12/10/2016
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CIV-E1010 Building Materials Technology
Lecture 01 – Mechanical and non-mechanical properties of building
materials12.09.2016
CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
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• Time: 12.09 – 20.10.2016• Lectures: Mondays and Tuesdays 14:00 to 16:00• Exercises: Thursdays 8:30 to 10:00• Status of the course: Master degree course• Academic Year, Period: Autumn 2016 (Period I)• Location: Otaniemi / Lecture hall R2• Language of Instruction: English• Course Website:
V is the volume under absolutecompact conditions (cm3).
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
1.3.1 Structural characteristics
Ways to determine densitya) Direct measurement of
mass and volumeØ When measuring liquids and
regularly shaped solids, massand volume can bediscovered by directmeasurement and these twomeasurements can then beused to determine density.
b) Indirect volumemeasurementØ To calculate the density of
solids with irregular surfacesØ Pour water into the
graduated cylinderØ Mark the original water levelØ Add the object to the water
and record the new waterlevel.
Ø The difference between thenew water level and theoriginal level will be theobject's volume.
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
Bulk Density (rb)• is the mass of a unit volume of
material in its natural state (withpores and voids)
• For most materials, bulk densityis less than density
• Properties like strength and heatconductivity are greatly affectedby their bulk density.
1.3.1 Structural characteristics
Material Bulk density (kg/m3)Brick 1600–1800Granite 2500–2700Sand 1450–1650Pine wood 500–600Steel 7850
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
1.3.1 Structural characteristics
Density Index (r0)• is the ratio,
• It indicates the degree to whichthe volume of a material is filledwith solid matter.Ø For almost all building
materials r0 is less than 1.0Ø no absolutely dense bodies in
nature.
Specific Weight (g)• aka. (the unit weight) = the weight
per unit volume of material,
• Specific weight can be used in civilengineering to determine theweight of a structure designed tocarry certain loads whileremaining un-broken andremaining within limits regardingdeformation.
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
1.3.1 Structural characteristics
Specific Gravity (Gs)• S.G. of solid particles of a
material is the ratio ofweight/mass of a givenvolume of solids to theweight/mass of an equalvolume of water at 4°C.
• Because the density ofwater in g/cm3 is 1.0, the SGof an object is will be almostthe same as its density ing/cm3.
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
Porosity (n)Porosity is ratio of the volume ofpores to that of the specimen
1.3.1 Structural characteristics
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
Void Ratio (e)• is defined as the ratio of
volume of voids (Vv) to thevolume of solids (Vs)
1.3.1 Structural characteristics
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
1.3.1 Structural characteristics
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
1.4.3 Mechanical Properties
Types of loadings:• Transverse• Axial loading• Torsional loadingProduced stress• Direct stress (direct tensile stress
or direct compressive stress)• Bending stress (tensile stress or
compressive stress)• Shearing stress,• Torsional stress, or• A combination of the different
stresses.
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
1.4.3 Mechanical Properties
Loading conditions:• Periodic load, repeats itself with
timeà For example, rotatingequipment in a building canproduce a vibratory load.
• Random load, the load patternnever repeats, such as thatproduced by earthquakes
• Transient load is an impulse loadthat is applied over a short timeinterval, after which thevibrations decay until the systemreturns to a rest condition. Forexample, bridges must bedesigned to withstand thetransient loads of trucks.
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
1.4.3 Mechanical Properties
Stress–strain relations
• Stress-strain curve - basic relationship that describesmechanical properties for static stresses to whichmaterials can be subjected:1. Tensile - stretching the material2. Compressive - squeezing the material3. Shear - causing adjacent portions of the material to
slide against each other
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
1.4.3 Mechanical Properties
Stress–strain relations• Stress = Force / Original area
• Strain
oAF
=s
o
o
LLL -
=e
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
1.4.3 Mechanical Properties
Stress–strain relations
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3
2
1
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
1.4.3 Mechanical Properties
Elastic behavior• Material returns to its
original length when stressis removed
• Relationship between stressand strain is linear
Hooke's Law:s = E e
where E = modulus ofelasticity
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
1.4.3 Mechanical Properties
Yield Point in Stress-Strain Curve• As stress increases, a point in the
linear relationship is finallyreached when the materialbegins to yieldØ Yield point Y can be identified
by the change in slope at theupper end of the linear regiono Y = a strength property
Ø Other names for yield point:o Yield strengtho Yield stresso Elastic limit
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
1.4.3 Mechanical Properties
Plastic Region• Yield point marks the
beginning of plasticdeformation
• The stress-strain relationshipis no longer guided byHooke's Law
• As load is increased beyond Y,elongation proceeds at amuch faster rate than before,causing the slope of the curveto change dramatically
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
1.4.3 Mechanical Properties
Viscoelastic behavior• Viscosity can be defined using two
parallel plates separated by adistance d and a fluid fills the spacebetween the two plates
• Typical viscoelastic materials usedin construction applications areasphalt and plastics
• Some of the properties ofviscoelastic materials are theirability to:Ø creep,Ø recover,Ø undergo stress relaxationØ absorb energy.
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
1.4.3 Mechanical Properties
Ductility• ability of material to undergo large deformations without rupture before
failure• beneficial to the users of the structuresà it will undergo large
deformations before failure and thus provides warning to the occupants
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CIV-E1010 Building Materials TechnologyFahim Al-Neshawy
Summary
We discussed:Ø The history of using
building materialsØ Types of materials used
by engineersØ The criteria of selecting
suitable buildingmaterial
Ø the material propertiesimportant to civilengineering:o Structural