G1 - LT #2

Question 1

Three basic elements of concrete are:

Answer 1

Cement, water and aggregates

Question 2

The rocklike substance produced by a kiln is called:

Answer 2

Clinkers

Question 3

The four basic ingredients used in the manufacture of cement are:

Answer 3

Iron, silica, alumina and limestone

Question 4

Normal Portland cement is now known as:

Answer 4

GU cement

Question 5

High Early strength hydraulic cement is:

Answer 5

HE cement

Question 6

LH cement is used for:

Answer 6

Low heat of hydration concrete

Question 7

Expansive cements cause concrete to:

Answer 7

Expand during setting

Question 8

Good aggregates should be shaped:

Answer 8

Round or cubical

Question 9

Fine aggregates are usually considered to be:

Answer 9

Less than 5 mm

Question 10

An accelerator is an example of an:

Answer 10

Admixturre

Question 11

The masonry cement best suited for foundation is:

Answer 11

Type M

Question 12

Major greenhouse gas produced by cement industry is:

Answer 12

CO2

Question 13

One way of reducing CO2 during cement production is to:

Answer 13

Decrease the amount of clinker used

Question 14

What is the proper size for a slump cone?

Answer 14

100 mm TOP Diameter
200 MM BOTTOM Diameter
300 MM HEIGHT

Question 14

Name three qualities of properly proportioned concrete mix:

Answer 14

Economical, workable, strong, durable finish

Question 14

How is slump measured?

Answer 14

The distance from the top of the cone to the top of concrete.

Question 15

To make strong, durable, concrete, the water-cement ratio should be:

Answer 15

LOW

Question 16

What is the importance of water-cement ratio and minimum cement content?

Answer 16

Strength of the mix and economy

Question 17

In concrete, aggregates make up:

Answer 17

60 to 80 percent of the mix concrete

Question 18

Except for slabs-on-grade, the size of aggregates should be ____ of one member

Answer 18

1/5th the thickness of one member

Question 19

Concrete that is being pumped should have:

Answer 19

A superplasticizer added

Question 20

When is high sulphate resistant hydraulic cement used?

Answer 20

Where soil or groundwater has a very high sulphate content

Question 21

Up to 20% of concrete can be replaced with:

Answer 21

Fly ash to reduce the cost of the concrete mixture.

Question 22

What is blended hydraulic cement?

Answer 22

Contains 25 to 70% granulated blast-furnace slag and up to a maximum of 40% pozzolan

Sets slower, improved properties in hardened concrete

Question 23

Air entrained Portland cements are useful for?

Answer 23

Improve resistance to freeze-thaw conditions and to scaling caused by chemicals applied for snow & ice removal.

Question 24

Oil-well cement used for”

Answer 24

Sealing oil and gas wells during drilling

Question 25

The entire amount of aggregates in concrete needs to be:

Answer 25

Mix of: Evenly graded pieces, not too many small and not too many large

Question 26

Exposed aggregate work uses what kind of aggregates?

Answer 26

Gap-graded aggregates, large size of 3/8 diam. next largest being sand. Gap produces an even pebbled surface to concrete.

Question 27

Water impurities in concrete mix can cause:

Answer 27

Efflorescence, staining or corrosion of re-bar

Question 28

When slabs on grade are not reinforced, what is the max. size of aggregate?

Answer 28

Not more than one-third of slab thickness