A2/A3- Concrete, Cement & Mortar Flashcards
The higher the water cement ratio mix, the _________ the concrete.
stronger
What creates paste for concrete?
Cement + water
Less paste forms a more ________ and __________ texture.
rough
porous
More paste creates __________.
cracking
What is the process of a substance reacting with water (that occurs for several weeks)?
Hydration.
Why are additives used for concrete?
1. ______________________.
2. _________________________________.
3. _____________________________________.
To enhance colour.
To enhance workability.
To enhance fire resistance.
Admixtures are __________ (retarders, water reducers) added to concrete before mixing.
chemicals
How long does it take for concrete to achieve full strength and hardness?
28 days.
What are the 4 types of concrete mixes?
1.
2.
3.
4.
- Prescribed mixes.
- Design mixes.
- Mixes by ratio of volume.
- Mixes by ratio of weight.
A prescribed mix is a mixture with _______________ of all _______________.
exact proportions
ingredients
A design mix is a mixture for a ______________ but with ____________ proportions.
specific task
inexplicit
What is a disadvantage of a ratio by volume mix?
It is carried out onsite so it lacks accuracy.
What is the ratio by weight mix mainly used for?
Bulk concrete.
What are 3 advantages of concrete?
- Inexpensive.
- Range of applications due to molds.
- Quick and easy to build.
Is concrete a good sound insulator?
Yes.
What is 1 disadvantage of concrete?
Lacks visual aesthetic.
What are 2 characteristics of aerated concrete blocks?
1.
2.
- Lightweight.
- Medium strength.
What is the difference in mixture between aerated blocks and other concrete blocks?
They contain lime, ash, and aluminium sulphate.
What are aerated blocks mainly used for?
Partitions.
What is high density concrete made of?
____________, __________ and ____________________.
Cement, sand and aggregates.
What are 2 characteristics of high density concrete blocks?
1.
2.
- Durable.
- High-strength.
What are high density blocks mainly used for?
Load bearing walls.
What is ICF made of?
____________ and ____________________.
Cement
recycled wood chip
What are 2 uses of insulated concrete form (ICF) blocks?
1.
2.
- Interlocks to create formwork.
- Integrated with mineral wool insulation.
Reinforced concrete has a ___________________ that allows a structure to remain _________ under loading.
high compressive strength
stable
Reinforced concrete is _________ and needs _______________, so there will be ______________________ once a building is constructed.
durable
little maintenance
minimal maintenance costs
What is cement?
A soft powder ready to be mixed into concrete or mortar.
What is the process to make Portland Cement?
1. Cement is processed in a ______________ to form ________________ (small grey pebbles).
- ___________________ is mixed with _____________ and fed into a __________________.
- The ___________________ is ground into ___________________ to become Portland Cement.
rotary kiln
cement clinker
Cement clinker
minerals
grinder machine
cement clinker
fine powder
What is mortar?
A __________-based ______-___________ adhesive.
cement
gap-filling
What are two main characteristics of mortar:
1.
2.
- Workability.
- Flexibility.
Mortar must have good _______________ to stand against the ______________ of a location.
weather resistance
specific climate
Mortar must have good workability to make it easier to do what?
Lay bricks.
What is mortar render?
A mixture applied to buildings to _______ a smooth finish.
render
What happens to blocks after mortar is applied to it?
They become resistant to _______________ and transmit ______________ effectively.
side-loading
vertical loads
What are the 4 types of mortar?
1.
2.
3.
4.
Cement mortar.
Lime mortar.
Cement lime mortar.
Coloured mortar.
How does mortar fail?
By crushing.
What are 2 characteristics of cement mortar (3:1)?
1.
2.
- Very strong.
- Quick setting.
What is cement mortar commonly used for?
Engineering bricks.
What are 2 characteristics of lime mortar (3:1)?
1.
2.
- Porous.
- Slow setting.
What is lime mortar commonly used for?
Older buildings.
What are 2 characteristics of cement-lime mortar?
1.
2.
- Water resistant.
- Quick setting.
Identify one way mortar can fail:
By crushing.
Coloured mortar is cement-lime mortar but with ____________________.
coloured additives.
Screed is a thin layer of ________________ spread over a concrete floor to make it ___________ and level.
cement mixture
smooth
