Cement Flashcards
(30 cards)
What is the oldest cementing material?
mud+straw in ancient eguypt
What did Babylonians used to bind stones with bricks?
Bitumen
What did ancient Egyptians used for the cons. of pyramids of Cheops?
Gypsum
Name 2 non-hydraulic binders
Lime mortars & Gypsum
How did the greeks and roman produced hydraulic lime?
by calcinating limestone containing clayey impurities
How did Joseph Aspdin created the portland cement?
By calcinating in a kiln finely ground limestone mixed with finely divided clay.
What are the steps for traditional manufacture of portland cement?
- Raw material storage
- Raw material grinding
- Raw material Blending
- Raw material cooking in kiln
- Clinker storage/cooling
- Gypsum addition
- Cement grinding
- Cement storage/loading
How is the modern manufacture of portland cement different than traditional?
(instead of Raw material grinding and Raw material Blending) –> Roller mill +
4. preheating of raw material
In the kiln, what happens up to 700C?
Nothing (water is lost)
In the kiln, what happens betwe. 700C and 900C?
C2S (belite) creation
In the kiln, what happens between 1150C to 1200C?
Belite+CaO
In the kiln, what happens between 1200C to 1350C?
C3S (ALITE)
In the kiln, what happens between 1350C to 1450C?
Less C2S, More C3S
In the kiln, what happens in the cooling process?
C3A (Tricalcium aluminate) and C4AF(Tetracalcium Aluminoferrite)
How do you calculate the % of main components of clinker?
using bogue’s equation
Name 4 raw material in portland cement
Lime
Alumina
Silica
Iron oxyde
Name the types of cement
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%)
What does GU, HE, MS, HS, MH and LH stands for?
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
What does PLC stand for:
Portland limestone cement
What does Gub stands for?
General used blended
SF?
silica fume
What are the hydration products?
CSH
CH
others
(+heat)
What is the cement hydration?
C3S
C2S
C3A
C4AF
+
H20
=
Hydration products (CSH & CH and others)
+
Heat
Which hydration product give strength to the cement?
CSH (Calcium Silica Hydrate)
