A2/A3- Concrete, Cement & Mortar

Question 1

The higher the water cement ratio mix, the _________ the concrete.

Answer 1

stronger

Question 2

What creates paste for concrete?

Answer 2

Cement + water

Question 3

Less paste forms a more ________ and __________ texture.

Answer 3

rough
porous

Question 4

More paste creates __________.

Answer 4

cracking

Question 5

What is the process of a substance reacting with water (that occurs for several weeks)?

Answer 5

Hydration.

Question 6

Why are additives used for concrete?
1. ______________________.
2. _________________________________.
3. _____________________________________.

Answer 6

To enhance colour.
To enhance workability.
To enhance fire resistance.

Question 7

Admixtures are __________ (retarders, water reducers) added to concrete before mixing.

Answer 7

chemicals

Question 8

How long does it take for concrete to achieve full strength and hardness?

Answer 8

28 days.

Question 9

What are the 4 types of concrete mixes?
1.
2.
3.
4.

Answer 9

1. Prescribed mixes.
2. Design mixes.
3. Mixes by ratio of volume.
4. Mixes by ratio of weight.

Question 10

A prescribed mix is a mixture with _______________ of all _______________.

Answer 10

exact proportions
ingredients

Question 11

A design mix is a mixture for a ______________ but with ____________ proportions.

Answer 11

specific task
inexplicit

Question 12

What is a disadvantage of a ratio by volume mix?

Answer 12

It is carried out onsite so it lacks accuracy.

Question 13

What is the ratio by weight mix mainly used for?

Answer 13

Bulk concrete.

Question 14

What are 3 advantages of concrete?

Answer 14

1. Inexpensive.
2. Range of applications due to molds.
3. Quick and easy to build.

Question 15

Is concrete a good sound insulator?

Answer 15

Yes.

Question 16

What is 1 disadvantage of concrete?

Answer 16

Lacks visual aesthetic.

Question 17

What are 2 characteristics of aerated concrete blocks?
1.
2.

Answer 17

1. Lightweight.
2. Medium strength.

Question 18

What is the difference in mixture between aerated blocks and other concrete blocks?

Answer 18

They contain lime, ash, and aluminium sulphate.

Question 19

What are aerated blocks mainly used for?

Answer 19

Partitions.

Question 20

What is high density concrete made of?
____________, __________ and ____________________.

Answer 20

Cement, sand and aggregates.

Question 21

What are 2 characteristics of high density concrete blocks?
1.
2.

Answer 21

1. Durable.
2. High-strength.

Question 22

What are high density blocks mainly used for?

Answer 22

Load bearing walls.

Question 23

What is ICF made of?
____________ and ____________________.

Answer 23

Cement
recycled wood chip

Question 24

What are 2 uses of insulated concrete form (ICF) blocks?
1.
2.

Answer 24

1. Interlocks to create formwork.
2. Integrated with mineral wool insulation.

Question 25

Reinforced concrete has a ___________________ that allows a structure to remain _________ under loading.

Answer 25

high compressive strength stable

Question 26

Reinforced concrete is _________ and needs _______________, so there will be ______________________ once a building is constructed.

Answer 26

durable little maintenance minimal maintenance costs

Question 27

What is cement?

Answer 27

A soft powder ready to be mixed into concrete or mortar.

Question 28

What is the process to make Portland Cement? 1. Cement is processed in a ______________ to form ________________ (small grey pebbles). 2. ___________________ is mixed with _____________ and fed into a __________________. 3. The ___________________ is ground into ___________________ to become Portland Cement.

Answer 28

rotary kiln cement clinker Cement clinker minerals grinder machine cement clinker fine powder

Question 29

What is mortar? A __________-based ______-___________ adhesive.

Answer 29

cement gap-filling

Question 30

What are two main characteristics of mortar: 1. 2.

Answer 30

1. Workability. 2. Flexibility.

Question 31

Mortar must have good _______________ to stand against the ______________ of a location.

Answer 31

weather resistance specific climate

Question 32

Mortar must have good workability to make it easier to do what?

Answer 32

Lay bricks.

Question 33

What is mortar render? A mixture applied to buildings to _______ a smooth finish.

Answer 33

render

Question 34

What happens to blocks after mortar is applied to it? They become resistant to _______________ and transmit ______________ effectively.

Answer 34

side-loading vertical loads

Question 35

What are the 4 types of mortar? 1. 2. 3. 4.

Answer 35

Cement mortar. Lime mortar. Cement lime mortar. Coloured mortar.

Question 36

How does mortar fail?

Answer 36

By crushing.

Question 37

What are 2 characteristics of cement mortar (3:1)? 1. 2.

Answer 37

1. Very strong. 2. Quick setting.

Question 38

What is cement mortar commonly used for?

Answer 38

Engineering bricks.

Question 39

What are 2 characteristics of lime mortar (3:1)? 1. 2.

Answer 39

1. Porous. 2. Slow setting.

Question 40

What is lime mortar commonly used for?

Answer 40

Older buildings.

Question 41

What are 2 characteristics of cement-lime mortar? 1. 2.

Answer 41

1. Water resistant. 2. Quick setting.

Question 42

Identify one way mortar can fail:

Answer 42

By crushing.

Question 43

Coloured mortar is cement-lime mortar but with ____________________.

Answer 43

coloured additives.

Question 44

Screed is a thin layer of ________________ spread over a concrete floor to make it ___________ and level.

Answer 44

cement mixture smooth