CMT Lesson 3

Physical Properties

Characteristics of matter not associated with a change in its chemical composition.

Mechanical Properties

Determine the range of usefulness of a material and establish the expected service life.

Chemical Properties

Observed when a substance undergoes a chemical change.

Electrical Properties

Ability to conduct or resist electricity through materials.

Magnetic Properties

Behavior of a material under a magnetic field, determining its suitability for magnetic applications.

Thermal Properties

Govern the rate of heat transfer between the inside and outside of a building.

Density

Dry mass per unit volume of a substance under absolute compact conditions.

Bulk Density

Mass per unit volume of a material in its natural state with pores and voids.

Specific Gravity

Ratio of weight/mass of a given volume of solids to the weight/mass of an equal volume of water at 4°C.

Porosity

Volume of material interspersed with pores, expressed as a ratio of pore volume to specimen volume.

Hygroscopicity

Property of a material to absorb water vapor from the air, expressed by moisture content.

Thermal Capacity

Property of a material to absorb and release heat when heated and cooled.

Flame Resistance

Property of a substance not to flame when contacting fire in the air.

Strength

Greatest stress a substance can bear under external force without destruction.

Elasticity

Ability to deform with external forces and return to its original shape when the stress is removed.

Corrosion Resistance

Material's ability to withstand degradation caused by chemical reactions with its environment.

Thermal Conductivity

Amount of heat transferred through a unit area of a specimen with unit thickness in unit time.

Density Index

• ratio of bulk density and density.

• the volume of a material is filled with solid matter.

Specific Weight

• the unit weight per unit volume of material

• density of distilled water at this temperature is equal (1 g/cm3 ) or (1000 kg/m3).

True or Absolute Specific Gravity

the specific gravity if both the permeable and impermeable voids are excluded to determine the true volume of solids

Apparent or Mass Specific Gravity

the specific gravity if both the permeable and impermeable voids are included to determine the true volume of solids

Void Ratio

• ratio between the volume of voids to the volume of solid material

Water Absorption

• water are exposed to water.

• expressed by the water-absorption ratio.

Weathering Resistance

ability of a material to endure alternate wet and dry conditions for a long period

Water Permeability

capacity of a material to allow water to penetrate under pressure.

Water Impermeability

• the ability of a material to resist the pressure of water or the infiltration of other liquids. 

• Materials like glass, steel, and bitumen are impervious.

Frost Resistance

the ability of water-saturated material to endure repeated freezing and thawing

Thermal Deformation

the property of a substance to expand with heat and contract with cold.

• Non-Flammable Materials

• Fire-Retardant Materials

• Flammable Materials

3 Types of Flame Resistance

Non-Flammable Material

cannot be fired, carbonized or slightly burned when contacting with fire

Fire-Retardant Materials

• hard to be burned or carbonized when contacting with fire 

• stop burning or slightly flaming immediately when leaving the fire.

Flammable Materials

• ignited or flame immediately when contact with fire

• continue to burn or slightly flame when leaving the fire.

Heat Conductivity

ability of a material to conduct heat

Refractoriness

• to withstand prolonged action of high temperature without melting or losing shape.

• the property of a material which cannot melt or lose its shape at prolonged high temperatures (1580 C or more).

Chemical Resistance

to withstand the action of acids, alkalis, seawater, and gases.

Durability

• to resist the combined effects of atmospheric pressure and other factors

• redistribution of stress at the ultimate limit state

Spalling Resistance

• ability of a material to undergo a certain number of cycles of sharp temperature variations without failing.

• describe areas of concrete which have cracked

Coefficient of Softening

• the ratio of compressive strength of a saturated material to its compressive strength in dry state.

• affects the strength of water absorbent materials like soil.

• Physical Properties

• Mechanical Properties

• Chemical Properties

• Electrical Properties

• Magnetic Properties

• Thermal Properties

PROPERTIES OF MATERIALS

• Density

• Bulk Density

• Density Index

• Specific Gravity

• True or Absolute Specific Gravity

• Apparent or Mass Specific Gravity

• Porosity

• Void Ratio

• Hygroscopicity

• Water Absorption

• Weathering Resistance

• Water Impermeability

• Water Permeability

• Frost Resistance

• Thermal Capacity

• Thermal Deformation

• Flame Resistance

• Heat Conductivity

• Refractoriness

• Chemical Resistance

• Durability

• Spalling Resistance

• Coefficient of Softening

PHYSICAL PROPERTIES

• Strength

• Elasticity

• Plasticity

• Brittleness

• Toughness

• Hardness

• Abrasive Resistance

• Fatigue

• Impact Strength

• Creep

MECHANICAL PROPERTIES

• Corrosion Resistance

• Ph Sensitivity

• Reaction With Water

• Compatibility With Adjacent Materials

• Chemical Resistance To Aggressive Substances

CHEMICAL PROPERTIES

• Thermal Capacity

• Thermal Conductivity

• Thermal Resistivity

• Specific heat

THERMAL PROPERTIES

• Durability

• Rheology

• Safety

• Purity

PROPERTIES OF MOST COMMONLY USED IN ASPHALT

• Strength

• Toughness

• Ductility

PROPERTIES OF MOST COMMONLY USED IN STEEL

Strength

• greatest stress

• substance can bear under external force (loads) without destruction.

Elasticity

• deform with external forces 

• return to its original shape when the stress is removed.

Plasticity

• describes the deformation of a material undergoing nonreversible changes of shape 

• ability of material to change its shape under load without cracking and to retain this shape after the load is removed

Brittleness

fractures when subjected to stress but has little tendency to deform before rupture.

Toughness

• impacted or vibrated by stress

• material is able to absorb much energy and deform greatly without rupture.

Hardness

property of a material to resist pressing-in or scratch of a sharp object.

Abrasive Resistance

• capacity of a material to resist abrasion.

• an ability to withstand the wear and tear of friction caused by mechanical parts

Fatigue

material is subjected to repeated loads, then the failure occurs at some point which is lower than the failure point caused by steady loads.

Impact Strength

• a material is subjected to sudden loads and it will undergo some deformation without causing rupture

• designates the toughness of material.

Creep

deformation caused by constant loads for long periods.

Corrosion Resistance

• material's ability to withstand degradation or deterioration caused by chemical reactions with its environment

• such as oxidation, rusting, or acidic attack.

Corrosion

Formation of rust (iron oxide) in metals, when they are subjected to atmosphere

Ph Sensitivity

affect their chemical stability and performance.

Reaction With Water

certain materials undergo chemical reactions with water, leading to hydration, expansion, or dissolution.

Compatibility With Adjacent Materials

essential to prevent adverse chemical interactions.

Chemical Resistance To Aggressive Substances

• Materials should possess resistance to aggressive substances encountered in their intended applications

• such as industrial chemicals, sewage, and aggressive soils.

Thermal Capacity

the property of a material to absorb heat and it is required to design proper ventilation.

Thermal Resistivity

the ability to resist heat conduction

Specific heat

• the quantity of heat required to heat 1 N of material by 1 deg C.

• useful when we use the material in high temperature areas.