Second Half

Question 0

Describe how a retaining wall works

Answer 0

Are designed with basic function of resisting the lateral pressure exerted by the soil and moisture

Question 1

What’ is a pile cap

Answer 1

It is used to tie the heads of a group of piles together, act as a base for the superstructure and provide an even base to work from

Question 2

What is the definition of angle of repose

Answer 2

Is the steepest angle if descent and dip relative to the horizontal plane to which a material can be piled without slumping

Question 3

List 4 different materials used for retaining walks

Answer 3

Timber logs
Masonry
Brickwork
In situ concrete

Question 4

List 4 different types of retaining walls

Answer 4

Gravity
Cantilever
Crib
Diaphragm walls

Question 5

What are the main raw materials of cement

Answer 5

Calcium
Silica
Alumina
Iron

Question 6

Describe the process of hydration

Answer 6

It’s a chemical reaction in which water combines with the various constituents of cement

Question 7

What is the time for initial set according to the AS

Answer 7

Initial setting before 60 mins final setting within 12 hours

Question 8

Why does so much water in the cement mix weaken the mix

Answer 8

Excess water will was the cement out

Question 9

Describe the curing and at what’s temperature does hydration stop

Answer 9

Process in which concrete is protected from loss of moisture and keep within a reasonable temperature range , stop at 0C

Question 10

What does tri-calcium aluminate do in cement

Answer 10

Has a very high rapid of hydration , contributes in setting and early hardening of cement

Question 11

What’ does tri-calcium silicate do in cement

Answer 11

Hydrates at a moderately fast rate and contributes in initial and final setting

Question 12

What does tetra calcium alumina ferrite do in cement

Answer 12

Affects the setting and early early strength because of it’s rapid hydration

Question 13

Describe what masonry cement are

Answer 13

Contains Portland cement and limestone and used for masonry mortar

Question 14

Describe cement

Answer 14

Mixer of cement
Water
Coarse
And fine aggregates

Question 15

List 5 points that’s effects the compressive strength in concrete

Answer 15

Water 
Density 
Age of concrete 
Type of cement 
Curing conditions 
Cement ratio

Question 16

Describe what tensile strength in concrete

Answer 16

A measure of the ability of concrete to hold together

Question 17

List 3 types of vibration in concrete

Answer 17

Immersion
Form
And surface vibration

Question 18

What can over vibration cause in concrete

Answer 18

Form damage
Concrete separation
And cracks

Question 19

Describe aerated concrete and list 3 points

Answer 19

Various Method have been used for producing the aeration of the concrete mix

• processes in which gas is produced by chemical reaction
• processes in which foam - producing substance is added to the mix to introduce and stabilise air bubbles
• process involving the use to excess water

Question 20

List 4 characteristics of concrete

Answer 20

Plastic mouldable when fresh
High compressive strength when hard
Low tensile strength
High resistance to fire