Cement

Question 1

What is the oldest cementing material?

Answer 1

mud+straw in ancient eguypt

Question 2

What did Babylonians used to bind stones with bricks?

Answer 2

Bitumen

Question 3

What did ancient Egyptians used for the cons. of pyramids of Cheops?

Answer 3

Gypsum

Question 4

Name 2 non-hydraulic binders

Answer 4

Lime mortars & Gypsum

Question 5

How did the greeks and roman produced hydraulic lime?

Answer 5

by calcinating limestone containing clayey impurities

Question 6

How did Joseph Aspdin created the portland cement?

Answer 6

By calcinating in a kiln finely ground limestone mixed with finely divided clay.

Question 7

What are the steps for traditional manufacture of portland cement?

Answer 7

1. Raw material storage
2. Raw material grinding
3. Raw material Blending
4. Raw material cooking in kiln
5. Clinker storage/cooling
6. Gypsum addition
7. Cement grinding
8. Cement storage/loading

Question 8

How is the modern manufacture of portland cement different than traditional?

Answer 8

(instead of Raw material grinding and Raw material Blending) –> Roller mill +
4. preheating of raw material

Question 9

In the kiln, what happens up to 700C?

Answer 9

Nothing (water is lost)

Question 10

In the kiln, what happens betwe. 700C and 900C?

Answer 10

C2S (belite) creation

Question 11

In the kiln, what happens between 1150C to 1200C?

Answer 11

Belite+CaO

Question 12

In the kiln, what happens between 1200C to 1350C?

Answer 12

C3S (ALITE)

Question 13

In the kiln, what happens between 1350C to 1450C?

Answer 13

Less C2S, More C3S

Question 14

In the kiln, what happens in the cooling process?

Answer 14

C3A (Tricalcium aluminate) and C4AF(Tetracalcium Aluminoferrite)

Question 15

How do you calculate the % of main components of clinker?

Answer 15

using bogue’s equation

Question 16

Name 4 raw material in portland cement

Answer 16

Lime
Alumina
Silica
Iron oxyde

Question 17

Name the types of cement

Answer 17

Type 1: normal
Type 2: Moderate sulfate resistance (lower C3A; 7.5%)
Type 3: High early strength ( Ground finer)
Type 4: Low heat of hydration (high C2S-C4AF and low C3S-C3A)
Type 5: High sulfate resistance (lower C3A; 3.5%)

Question 18

What does GU, HE, MS, HS, MH and LH stands for?

Answer 18

HE: High early strength
GU: General Use
MS: Moderate sulfate resistance
HS: High sulfate resistance
MH: Moderate heat of hydration
LH: Low heat of hydration

Question 19

What does PLC stand for:

Answer 19

Portland limestone cement

Question 20

What does Gub stands for?

Answer 20

General used blended

Question 21

SF?

Answer 21

silica fume

Question 22

What are the hydration products?

Answer 22

CSH
CH
others
(+heat)

Question 23

What is the cement hydration?

Answer 23

C3S
C2S
C3A
C4AF
+
H20
=
Hydration products (CSH & CH and others)
+
Heat

Question 24

Which hydration product give strength to the cement?

Answer 24

CSH (Calcium Silica Hydrate)

Question 25

What does finer particles lead to in cement?

Answer 25

Finer –> Faster hydration, more heat generation, HE, lower long term strength

Question 26

Name three test for cement?

Answer 26

Blaine ASTM C 204( t air pass cement)
ASTM C 114 (chemical analysis to determine oxyde)
Wagner ASTM C 115
BET (measure SA)

Question 27

How long is the initial set and final set? and which test used to find values

Answer 27

IS: 1hr to 4 hours
FS: 3 to 6hrs
ASTM C 266 and 191

Question 28

What does ASTM C 186 test’s for?

Answer 28

Measure heat generated from cement as it hydrates.

Question 29

What does compressive strength (of cement) is influenced about?

Answer 29

Cement comp. & Fineness of cement

Question 30

Why thermal analysis?

Answer 30

To know when to break the bonds