Physical and Mechanical Properties og Materials

Question 1

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 1

Specific Gravity

Question 2

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

Answer 2

Density

Question 3

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

Answer 3

Bulk Density or Unit Weight

Question 4

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

Answer 4

Porosity

Question 5

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 5

Water Absorption

Question 6

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 6

Hygroscopicity

Question 7

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

Answer 7

Permeability

Question 8

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 8

Fire Resistance

Question 9

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 9

Thermal Properties

Question 10

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

Answer 10

Corrosion

Question 11

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

Answer 11

Durability

Question 12

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 12

Soundness

Question 13

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

Answer 13

Mechanical or Strength PropertiesMechanical or Strength Properties

Question 14

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 14

Elasticity

Question 15

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 15

Plasticity

Question 16

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

Answer 16

Toughness

Question 17

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

Answer 17

Resilience

Question 18

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

Answer 18

Hardness

Question 19

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

Answer 19

Brittleness

Question 20

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 20

Ductility

Question 21

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

Answer 21

Fatigue

Question 22

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 22

Creep

Question 23

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 23

Abrasive Resistance

Question 24

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

Answer 24

Impact Strength

Question 25

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

Answer 25

Strength Properties

Question 26

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

Answer 26

Tensile strength

Question 27

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

Answer 27

Compressive strength