lecture 01 – mechanical and non- mechanical properties of ... · • mud brick, • masonry...

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:

https://mycourses.aalto.fi/course/view.php?id=12977

Basic information


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Instructors’ contact information:

• Prof. Jussi Leveinen (Geomaterials)

• Prof. Jouni Punkki (Cement BasedMaterials)

• Teacher: D.Sc. Fahim Al-Neshawy

• Course assistant: Kirsi Heikkinen

• E-mail: [email protected]

Basic information


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1. Knowledge:Ø will be able to learn basic theory about main building- and

construction materials:• material composition / Properties• applications in buildings and structures

2. Skills:Ø be able to make right and well-founded choice of materials

3. General competence:Ø understand how properties of materials can be related to

the characteristics of the material.

Learning outcomes

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1. Engineering concepts of building materials

2. Engineering properties of stones and aggregates

3. Cementitious materials and masonry products

4. Thermal insulation materials

5. Bituminous materials

6. Reinforcement steels and composite materials

Course content


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• Attending Lectures

• Weekly exercises – individual work

• Laboratory exercise – Group work

• Exam

Learning methods and activities

50 %

50 %


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Course assessmentActivity Quantity Points Total Grading

Individualand groupwork

Attending lectures 12 10

50

0 < 25 p

1 26 - 30

Exercises 6 30 2 31 - 35

3 36 - 40

Laboratory report 1 10 4 41 - 45

5 > 45

Exam (5 Questions) 1 50 50

0 < 25 p

1 26 - 30

2 31 - 35

3 36 - 40

4 41 - 45

5 > 45

For passing the course:• a minimum grade of (1) is required for the individual and group work and• a minimum grade of (1) is required for the exam.


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• Course content?• How to pass the course?• Teaching Staff?• Anything else?

Questions?

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Lecture 1. Mechanical and non-mechanical properties of

building materials

1.1 History of building materials

1.2 Introduction to building materials

1.3 Fundamental Properties of Building Materials

1.3.1 Parameters of state / structural characteristics

1.3.2 Physical properties

1.3.3 Mechanical properties

Lecture contents


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1. Knowledge:Ø will be able to learn basic theory about main building- and

construction materials:• material composition / Properties• applications in buildings and structures..

2. Skills:Ø be able to make right and well-founded choice of materials

3. General competence:Ø understand how properties of materials can be related to

the characteristics of the material.

Lecture outcomes


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Arch. Kevin Espina - History of Architecture

Pre-Historic

Egyptian

Near EastMesopotamian

GothicRoman Renaissance 18th-19th C:Revival

20th C:Modern

Greek

The HistoricalTimeline of Architecture

3000B.C.

300B.C.

1stcenturay

2nd

centuray

16thcenturay

17thcenturay

19thcenturay

21stcenturay


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Pre-Historic

Egyptian

Near EastMesopotamian


Before 3000 B.C.• Animal skins,

wooden frames,animal bones

3000 – 2350 B.C.• Clay, soil, reeds, rushes• Mud & Straw Bricks• Timber, copper, tin,

lead gold, silverimported

3050 –332 B.C.• Stone• Metal and timber

were imported• Mud Bricks• Reeds, Papyrus, Palm

etc.

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GothicRomanGreek


900 B.C. until the 1stcentury• Marble, Limestone,• mud brick,• masonry blocks• Timber and terra

cotta

100 B.C. – 400 AD• Stone sand, gravel• Marble• Earth for terra

cotta and bricks

Europe 12th to 16th

century• Red bricks, glazed

bricks and whitelime plaster


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Renaissance 18th-19th C:Revival

20th and 21st C:Modern


Industrial revolution• Cement and

concrete

• New and advancedmaterials

• Green buildingmaterials

• Sustainable buildingmaterials

Europe 14th to 17th

century• Marble• Bricks• Pilasters


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What is Building Material?• B.M. is any material which is used for construction purposes

in the form of solid, semi-solid or liquid, processed orunprocessed (raw material).

Ø Natural Building materials: clay, mud, rocks, sand, andwood, even twigs and leaves

Ø Man-made (synthetic) products: fired bricks and clayblocks, ceramics, cement, composites, concrete, thermaland sound insulation, glass, metal, plastics, polymers,etc.



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1.2 Introduction to building materialsResponsibilities of material engineer:Ø Selection of materials for structure elements (roofs,

walls, floors, sub-structures, etc.)Ø Specification of materialsØ Quality control of materials

Ø These responsibilities fulfillment must meet certaincriteria includes:o Climatic / culture conditionso Economic factorso Mechanical and non-mechanical propertieso Production/Construction considerationso Aesthetic consideration

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Discussion (5 – 10 min)

Family house• Structural elements?• Select suitable building

materials for each element• Factors affecting your

selection

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1.3 Properties of Building Materials

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1.3.1 Structural characteristics

• Density and unit weight• Porosity

Structural characteristics

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Density (r)• Density (AKA Practical density) is

the mass of a unit volume ofhomogeneous material

• Density of some buildingmaterials:

Material Density (kg/m3)Ø Brick 2500 – 2800Ø Granite 2600 – 2900Ø Cement 2900 – 3100Ø Wood 1500 – 1600Ø Steel 7800 – 7900Ø Concrete 2400

V is the volume under absolutecompact conditions (cm3).

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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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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.


Material Bulk density (kg/m3)Brick 1600–1800Granite 2500–2700Sand 1450–1650Pine wood 500–600Steel 7850

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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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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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Porosity (n)Porosity is ratio of the volume ofpores to that of the specimen


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Void Ratio (e)• is defined as the ratio of

volume of voids (Vv) to thevolume of solids (Vs)


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1.4.2 Physical Properties

• Hydro-physical properties• Thermal properties• Viscosity

Physical properties

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Water absorption• denotes the ability of

the material to absorband retain water.

• It is expressed aspercentage in weightor of the volume ofdry material


Water absorption test

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Thermal Conductivity (k or l)• is the material ability to conduct

heat.• The faster heat flows through a

material, the more conductive it is.


· k = the thermal conductivity of thematerial (W/mK).

· q = the resultant heat flow (Watts)· A = the surface area through which

the heat flows (m²)· ∆T = the temperature difference

between the warm and cold sidesof the material (K)

· L = the thickness / length of thematerial (m)

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Thermal Expansion


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• Viscosity is a measure ofthe resistance of a fluidwhich is being deformed byeither shear or tensilestress.

• In everyday terms (and forfluids only), viscosity is"thickness" or "internalfriction".

• Thus, water is "thin", havinga lower viscosity, whilehoney is "thick", having ahigher viscosity.

• Viscosity describes a fluid'sinternal resistance to flowand may be thought of as ameasure of fluid friction.

• Plastic viscosity of concreteis critical for the concreteindustry because it affectsplacement and workability.

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1.4.3 Mechanical Properties

• Strength / Loadings• Stress–strain relations• Elastic behavior• Elastoplastic behavior• Viscoelastic behavior• Ductility

Mechanical properties

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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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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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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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Stress–strain relations• Stress = Force / Original area

• Strain

oAF

=s

o

o

LLL -

=e

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Stress–strain relations

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3

2

1

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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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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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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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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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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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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

characteristicso Physical propertieso Mechanical properties

• Next Lecture: Sustainabledesign, Material variability,and Nature of materials

lecture 01 – mechanical and non- mechanical properties of ... · • mud brick, • masonry...

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