CMT MODULE3

Question 1

The properties of materials depends on their type or classification;

Answer 1

Physical Properties

Question 2

The ratio of the weight of material per unit volume (not including air holes and pores). This property is used to calculate the density and porosity of
materials.

Answer 2

Specific Gravity

Question 3

Defined as the mass of a material per unit of its volume.

Answer 3

Density

Question 4

Defined as the total weight including solids and voids of
any granular materials per unit of its total volume.

Answer 4

Bulk Density

Question 5

The ratio of the volume of voids in a material to the total volume of granular material.

Answer 5

Porosity

Question 6

The property of a material by whereby it absorbs water from the ambience or
atmosphere and this property is important in the case of stones, bricks, etc.

Answer 6

Water Absorption

Question 7

The property whereby a material absorbs water present in the ambience or
atmosphere, as in the case of salt, sugar, etc. Timber is hygroscopic material.

Answer 7

Hygroscopicity

Question 8

The property whereby a material allows water to pass through its pores and this is
important in the case of soils.

Answer 8

Permeability

Question 9

There are materials like petrol are inflammable (readily catch fire) while others
are combustible (can be burnt but may not be rapidly ignite). Timber is combustible but not
inflammable. In addition, fire raises the temperature of otherwise fire-resistant materials,
sometimes causing damage by expansion.

Answer 9

Fire Resistance

Question 10

These are important in the heating or cooling rooms and in
designing suitable thermal insulation and the following are important in terms of heat
capacity, thermal resistivity, and sound transmission.

Answer 10

Thermal Properties

Question 11

The gradual destruction or damaging process of a metal or alloy due to
chemical processes such as oxidation.

Answer 11

Corrosion

Question 12

The resistance of a material to destruction or damaging process by natural
agencies.

Answer 12

Durability

Question 13

The resistance of a material to its deterioration or decaying process due
to heat, alternate freezing and thawing, etc. and this is important in the case of
cement, aggregate, etc.

Answer 13

Soundness

Question 14

These refer to properties whereby materials resist various straining actions or forces.

Answer 14

Mechanical or Strength Properties

Question 15

The property of a material whereby it tends to regain its shape after the
removal of an applied load. The stress at the limiting point is known as elastic limit.

Answer 15

Elasticity.

Question 16

The property of a material whereby it retains a change in shape or size after
the removal of the load and this is important when a material has to be molded into
different sizes and shapes.

Answer 16

Plasticity.

Question 17

The property of a material whereby it absorbs energy due to straining
actions by undergoing plastic deformation.

Answer 17

Toughness.

Question 18

The ability of a material to recover its size and form after deformation or
application of load.

Answer 18

Resilience.

Question 19

The resistance offered by any material to indentation, scratching, cutting,
or wear by abrasion or scratching.

Answer 19

Hardness.

Question 20

This refers to the tendency of a material to shatter or to break down on
receiving a shock.

Answer 20

Brittleness.

Question 21

The capacity to undergo large plastic deformation before actual failure and
this property allows the drawing of thin wire or stretching of a metal.

Answer 21

Ductility.

Question 22

The failure of a material by cracking resulting from repeated straining
action or repeated application of load.

Answer 22

Fatigue.

Question 23

The property whereby a material undergoes deformation with respect
to time under a constant load and this is over and above the instantaneous
elastic strain.

Answer 23

Creep.

Question 24

The ability of a material to resist wearing due to contact
with another surface moving with respect to it or by scratching from another
material which is important in road surfaces, warehouse floors, etc.

Answer 24

Abrasive Resistance.

Question 25

Refers to the ability of a material to withstand or resist shock.

Answer 25

Impact Strength.

Question 26

This is important in designing structural elements to
resist various types of load and the basic strengths are:

Answer 26

Strength Properties.

Question 27

The maximum stress a material can withstand or resist under
a tensile (stretching) load before failure.

Answer 27

Tensile strength.

Question 28

The maximum stress a material can resist or withstand
without failure under a compressive load.

Answer 28

Compressive strength.

Question 29

The maximum stress at failure under a shearing load (a load
parallel to the cross-section of the member).

Answer 29

Shear strength.