cement

Question 1

What is portland cement (pc)

Answer 1

is the mineral binding material used to manufacture concrete

Question 2

what is hydration reaction

Answer 2

when cement reacts with water

Question 3

it hydrates, sets, and hardens in?

Answer 3

air or under the water

Question 4

what is cement paste ?

Answer 4

cament+water

Question 5

what the cement do in concrete ? and what is the % volume of cement in concrete

Answer 5

it cover the coarse and fine aggregates to make concrete (cement past = 25% by volume of concrete )

Question 6

who discover cement and when?

Answer 6

joseph in 1824

Question 7

what are types of instant glue and what it’s for?

Answer 7

its portland cement , wich bound the aggregates togather

Question 8

what is step 1 of the production of portland cement?
or What are the materials of portland cement ?

Answer 8

2 basic raw (خام) material :
1. calcareous(جيري ) material ( limestone, chalk )
2. argillaceous material (طيني) ( silica, aluminum)

Question 9

what is step 2 of the production of portland cement?

Answer 9

1. storage of raw material
2. stone is sieved to125 mm to 20mm STORED

Question 10

what is step 3 of the production of portland cement?

Answer 10

Obtaining the chemical composition

Question 11

what is step 4 of the production of portland cement?

Answer 11

mixing and grinding (smash) of raw material

Question 12

what are the 2 wayes of mixing and grinding of the raw material ?

Answer 12

dry process : grinding and blending are done with dry material
wet process : grinding and blending are done with material mixed with water in a slurry form(between saturated and dry) (water content 35 to 50%)

Question 13

why is important to mix the materials?
why the homogeneity of raw material is very important?

Answer 13

because part of the reaction happens by diffusion in solid materials

Question 14

wet process recombine

Answer 14

1. lime cao , silica sio2 , alumina al2o2 recombine
2. then we call it clinker

Question 15

what is clinker

Answer 15

limestone+clay +1450c = clinker (in wet process)

Question 16

diff between wet and dry process ?

Answer 16

1. wet is more homogenous clinker
2. wet is more using energy
3. Dry process requires shorter/smaller kilns
4. Dry process has a lower production cost

Question 17

combining both process (semi‐wet process)

Answer 17

Water content = 12%
◦ Smaller kilns than the wet process
◦ Fuel consumption is lesser than wet (100 kg/ton)

Question 18

Burning process makes up…?

Answer 18

40‐60% of the total production cost

Question 19

why Kilns have to operate continuously ?

Answer 19

to ensure steady process and uniform clinker production

Question 20

what is step 5 of the production of portland cement?

Answer 20

Burning changes raw mix chemically into cement clinker

Question 21

what is step 6 of the production of portland cement?

Answer 21

Different stages of preheater are used to dry wet mixed
material(shorter klinks)

Question 22

what is step 7 of the production of portland cement?

Answer 22

1.Clinker is cooled down
2. Clinker is ground with gypsum (CaSO4) to produce Portland Cement
3.Gypsum is used to prevent flash setting of concrete

Question 23

Summary of steps to PC Production

Answer 23

1.Quarrying raw materials
2. Grinding raw materials
3.Mixing raw materials (dry or wet process)
4.Burning in rotary kilns at 1450°C
4.Cooling clinker
5.Grinding clinker with gypsum to produce Portland Cement

Question 24

give me short cut of these compunds ,and the percentage in cement
Oxide composition
CaO
SiO
Al2O3
Fe2O3
MgO
H2O
SO3

Answer 24

C (60 to 67%)
S(17 to 25%)
A( 3 to 8%)
F( 0.5 to 0.6)
M(0.5 to 4%)
H
S”(2 to 3.5%)