Concrete 1

Question 1

what elements does concrete contain?

Answer 1

cement, water, aggregates (coarse/fine) admixtures, additives

Question 2

what is Portland cement made up of?

Answer 2

calcium oxide + silicon dioxide + aluminium oxide

limestone, sands and clay

Question 3

what are the stages of the manufacturing Portland cement?

Answer 3

1) blending and grinding of clay and limestone
2) pre heat
3) kiln
4) cooling and grinding

Question 4

what is the reaction of cement and water called?

Answer 4

hydration reaction

Question 5

what is artificial stone and how is it made?

Answer 5

when cement reacts with water and bind aggregate into hard, strong material (artificial stone)

Question 6

what is dissolution?

Answer 6

when cement dissolves in the water making a porous solution

Question 7

how are aggregates classified?

Answer 7

weight, source, shape and size

Question 8

what are admixtures?

Answer 8

small components that are added to cement to change or more properties (added in water)

Question 9

what are the different types of admixtures?

Answer 9

plasticisers (reduce water), super plasticisers, retarder (contort large pours), accelerators (increasing strength), air retraining agents (creating bubbles)

Question 10

what is the function of additives?

Answer 10

they replace cement content while modifying the properties

Question 11

what are the 2 type of additives?

Answer 11

type1 (inert additions), type 2 (active additions/ pozzolans)

Question 12

what is are inert additions?

Answer 12

additions that improve the consistency and cohesiveness of the concrete (only use with self compacting concrete)

Question 13

what are the different types of pozzolans?

Answer 13

PFA- burned coal from power plants
GGBS- rapid cooling of slag
CSF- particle of silicon condense from the fumes of production of silicon alloys
Metakaolins- burnt kaolin