Cement Physical Testing Methods
Cement Physical Testing Methods
Cement Physical Testing Methods
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If H.F is very small the volume of the cement paste will increase which
lead to destroy the cement paste, but, if H.F is very high the cement
paste will be milled.
3- K factor calcium- (Kyool):
95 )% - 0 (
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3 2 7 . 0 3 2 1 . 1 2 8 . 2
* 100
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4- A to F factor (A/F):
4 ) - (
1
3 2
3 2
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Physical Properties of Portland Cement
Fineness
Soundness
Consistency
Setting time
False set and flash set
Compressive strength
Heat of hydration
Loss on ignition
Density
Bulk density
Sulfate expansion
Fineness
Fineness of cement is also important; it affects:
rate of hydration (rate of hydration increases with increasing fineness)
rate of setting (setting time decreases with increasing fineness)
-increase hydration-
durability (ASR) (high cement fineness reduces the durability of
concrete to freeze )
rate of carbonation during storage
cost
rate of gypsum addition (increased fineness required a grate amount
of gypsum )
bleeding (Increasing fineness tend to decrease the amount of bleeding )
However, later strength is not directly affected.
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Blaine Fineness Apparatus
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Soundness
The main purpose of the soundness test is to assess the possible
risk of late expansion due to hydration of un combined calcium
oxide and/or magnesium oxide. The test uses apparatus known as
Le Chatelier apparatus, which magnifies any expansion during
heating to a value that can be measured.
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consistency
The main purpose of the consistency test is to determine the
required quantity of water to obtain a standard or homogeneous
past ,and water quantity is enough to hydration process.
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Setting time
The time it takes for a cement to stiffen to a standard value after
addition of water is commonly known as the set time. The test
involves mixing cement with water and then measuring its
resistance to penetration of a standard probe at varying intervals of
time, until a certain value is reached.
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Factors affecting setting time:
(Fineness w/c ratio cement age Heat cement components)
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Early stiffening (False set & Flash set)
False set refers to the rapid development of rigidity without the
evolution of much heat.
Flash set (quick set) refers to the rapid development of rigidity
without the evolution of considerable heat.
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