CMT 2

PROPERTIES

● Physical

● Mechanical

● Thermal

● Chemical

● Technologica

PHYSICAL PROPERTIES

● A property of matter that is unrelated to a change in its chemical composition.

● Defined as a property of matter that can be measured and observed without changing a material's chemical nature.

PHYSICAL PROPERTIES OF BUILDING MATERIALS

● These are the properties required to estimate the material's quality and condition in the absence of any external force.

BULK DENSITY

● the mass-to-volume ratio of a material in its natural state, which includes voids and pores. It is measured in kilograms per cubic meter.

POROSITY

defined as the ratio of the volume of pores in a substance to its total volume

DURABILITY

The ability of a material to withstand all atmospheric forces without losing strength or shape

DENSITY

measured by dividing the mass unit by the volume unit (kg/m3).

DENSITY INDEX

the ratio of a material's bulk density to its density.

SPECIFIC GRAVITY

defined as the ratio of the unit weight of one material to the unit weight of the reference material (typically water at 4 degrees Celsius).

FIRE RESISTANCE

The ability to withstand fire without losing shape or other properties.

FROST RESISTANCE

material's ability to withstand freezing or thawing

WEATHERING RESISTANCE

The ability of a material to withstand all atmospheric forces while retaining its strength and shape

SPAILING RESISTANCE

a material's ability to withstand a certain number of cycles of abrupt temperature changes without failing.

WATER ABSORPTION

ability of the material to absorb and retain water

WATER PERMEABILITY

material's ability to allow water to pass through it.

HYDROSCOPICITY

The ability of a material to absorb water vapor from the air

COEFFICIENT OF SOFTENING

The ratio of its saturated compressive strength to its dry compressive strength.

REFRACTORINESS

The property of a material that does not melt or lose its shape at high temperatures for an extended period of time (1580 degrees C or more).

MECHANICAL PROPERTIES

properties of the materials that are found out by applying external forces on them

STRENGTH

The capacity of a material to resist failure caused by loads acting on it is determined by dividing the ultimate load taken by the material with its cross sectional area.

HARDNESS

resistance of that material to an indentation or plastic deformation

ELASTICITY

The capacity of a material to regain its initial shape and size after removal of load

PLASTICITY

the ability of a material to undergo permanent deformation under stress without cracking

BRITTLENESS

describes the property of a material that fractures when subjected to stress but has a little tendency to deform before rupture

FATIGUE

Occurs after a lengthy period of repeated stress cycling - material becomes “Tired”

CREEP

the tendency of a solid material to undergo slow deformation while subject to persistent mechanical stresses

IMPACT STRENGTH

the ability of a material to withstand a suddenly applied load, either from a force upon the material or the material itself being dropped

ABRASION RESISTANCE

makes it durable and provided long life

THERMAL PROPERTIES

associated with its heat conductivity.

HEAT

total energy of the motion of the molecules of a substance

TEMPERATURE

measure of the average energy of the motions of the molecules in the substance

HEAT CAPACITY

The amount of heat needed to raise a material's temperature by one degree

THERMAL CONDUCTIVITY

The ability of a substance and materials to conduct heat is one of its fundamental properties

THERMAL EXPANSION

Usually expressed as a fractional change in dimensions per unit temperature change

● Linear thermal expansion. \\

● Areal thermal expansion.

● Volume thermal expansion.

3 TYPES OF THERMAL EXPANSION

MELTING POINT

The temperature at which a substance transforms from a solid to a liquid at atmospheric pressure

THERMAL DIFFUSIVITY

The ratio of thermal conductivity and heat capacity

THERMAL SHOCK RESISTANCE

is the effect of a sudden change of temperature on a material whereas thermal shock resistance

THERMAL STRESSES

When expansion or contraction of a body due to temperature change is wholly or partially prevented, ------- will be developed in the body.

THERMO-ELASTIC EFFECT

When a solid is subjected to a load, work is done on it and it changes in volume.

CHEMICAL PROPERTIES

The ability of construction materials to resist the effects of chemicals like acids, salts and alkalis is called chemical resistance.

ATOMIC BONDING

represents how atoms are bonded to each other to form the material.

IONIC BOMND

COVALENT BOND

METALLIC BOND

TYPES OF ATOMIC BONDS

IONIC BONDS

forms by exchanging of valence electrons between atoms

COVALENT BOND

\- forms by sharing of electrons between atoms

METALLIC BOND

FOUND IN METALS

CORROSION RESISTANCE

ability of material to resist oxidation in atmospheric conditions.

ACIDITY OR ALKALINITY

ability of the water body to neutralize acids and bases and thus maintain a fairly stable pH level.

SOLUBILITY

defined as the maximum amount of a substance that will dissolve in a given amount of solvent at a specified temperature.

MACHINABILITY

defines the ease at which a material (mainly metal) can be cut or shaped while providing a satisfactory surface finish.

TECHNOLOGICAL PROPERTIES

qualities which give information regarding the suitability of metals for various technological operations or processes.

● A good surface finish can be produced.

● Higher cutting speeds can be used. ● The metal removal rate is high.

● Cutting tool wear is low.

● Low power consumption.

PROPERTIES OF HIGH MACHINABILITY METAL

MACHINABILITY INDEX

used to compare the machinability of different metals.

WELDABILITY

ability of any material (usually metals and its alloys) to weld with similar materials.

ALUMINUM

CAST IRON

COPPER

STAINLESS STEEL

DIFFERENT METALS THAT HAVE GOOD WELDABILITY

CASTABILITY

the ease with which a metal can be cast into form.

FLUIDITY OF METAL

An ability of metals and alloys to flow through the gating system filling the cavity of the casting mold and conforming its shape.

SOLIDIFICATION INTERVAL

VISCOSITY

SURFACE TENSION

FACTORS OF DETERMINING FLUIDITY

SHRINKAGE

It is the reduction in volume of a metal when it goes from a molten to a solid state.

LOW GAS POROSITY

Gas porosity occurs because the molten metal can hold a large amount of dissolved gas, unlike the solid form

FORMABILITY

Ability of a given material workpiece to undergo plastic deformation without being damaged or failure such as fracture

MALLEABILITY

Ability to be stretched/deformed/molded into a sheet.

LEAD

GOLD

PLATINUM

BRASS

APPLICATION OF MALLEABLE MATERIALS

CEMENT

\- is broadly described as a material having an adhesive and cohesive property with the capacity to bond the material like stone, bricks, building blocks, etc. C

● Very easy to use

● Provides durable and long-lasting repairs

● Cost-effective ● Does not corrode or rust if corrosion material resistant is used ● Low maintenance

ADVANTAGES OF CEMENT

● Once mixed with water, cement only remains workable for 10 to 15 minutes.

● It also does not work on frozen surfaces or if the temperature suddenly drops dramatically low.

● It’s really tough to provide ideal curing conditions.

DISADVANTAGES OF CEMENT

NATURAL CEMENT

\- It is manufactured from limestones containing 20 to 40 percent of clay, the remainder being carbonate of lime mixed with carbonate of magnesia

ARTIFICIAL CEMENT

\- It is made from a mixture of Lime, Silica, Alumina, Iron oxide, Magnesia, etc.

ORDINARY PORTLAND CEMENT

most common type of cement used in construction.

RAPID HARDENING CEMENT

type of cement that sets and hardens quickly, usually within a few hours of mixing.

QUICK SETTING CEMENT

similar to RHC in that it sets and hardens quickly, but it sets even faster.

LOW HEAT CEMENT

designed to produce less heat during the hydration process, which can help prevent cracks from forming in large concrete structures.

SULPHATE RESISTING CEMENT

type of cement that is designed to resist damage from sulphate ions, which can be found in soil and water

PORTLAND SLAG CEMENT

type of cement that contains slag, a by-product of steel production.

PORTLAND POZZOLANA CEMENT

a type of cement that contains pozzolanic materials, which are natural or artificial materials that react with calcium hydroxide to form compounds that increase the strength and durability of concrete.

AIR ENTERTAINING CEMENT

type of cement that contains air - entraining agents, which create tiny air bubbles in the concrete.

COLORED CEMENT

a type of cement that contains pigments, which give the concrete a specific color.

EXPANSIVE CEMENT

a type of cement that expands slightly as it sets, which can help compensate for shrinkage in the concrete.

HIGH ALUMINA CEMENT

type of cement that is made from bauxite and limestone, rather than the typical raw materials used in OPC

HYDROPHOBIC CEMENT

a type of cement that is designed to repel water.

MASONRY CEMENT

type of cement that is specifically designed for use in masonry construction, such as bricklaying and plastering.

OIL WELL CEMENT

a type of cement that is used in the construction of oil and gas wells.

WHITE CEMENT

type of cement that is made from raw materials that are low in iron and magnesium, which gives it a white color