Faculty
of Engineering
Materials of
Construction
Lab
Experiment No :
( 2 )
Experiment Name :
(Standard
Test Method for Density of Hydraulic
Cement)
Prepared by :
Khaled
osama khaled naeem
I.D Number.:
Date of Exp.:
2013/3/17
Supervisors:
Dr.sami aiad
Density of
Hydraulic Cement
Introduction :
To design concrete
mixture we must know the density of
hydraulic cement, in order to calculate its weight and volume.
Scope :
This test method covers determination of the
density of hydraulic cement. Its particular usefulness is in connection
with the design and control of concrete mixtures .
Apparatus :
1-Le Chatelier Flask
:The Standard flask which is circular in
cross
section with standard shape and
dimensions .
(i) There should be at
least 10 mm between the highest
graduation mark and the lowest point of
grinding for the glass stopper.
(ii) The neck shall be
graduated from o – 1 mL and from
18 to 24 mL in 0.1 mL graduations .
(iii) The error of the
indicated capacity of the flask
shall not be more than 0.05 mL.
2-Kerosine :That will
be used in the density determination shall be free of
water and having a density greater than 0.73 g/mL at 23±2ºc
.
3 –sensitive balance :
A suitable, as per requirements of section 4.2.1 of Test methods C 114, balances with accuracy
of ±0.05 g.
4- water Bath
5- Funnel
6- cement
Theory :
Cement density ( ρ ): it’s the mass of
cement measured by (gram) on the displaced volume measured by (cm³) that’s
expressed as follow:
ρ ( g / cm³ ) = mass of cement (g) / displaced
volume (cm³)
the displaced volume measured as following:
Displaced volume (cm³) = Final reading –
Initial reading
Final reading & Initial reading ( from
trial )
Procedures :
Theory :
Cement density ( ρ ): it’s the mass of
cement measured by (gram) on the displaced volume measured by (cm³) that’s
expressed as follow:
ρ ( g / cm³ ) = mass of cement (g) / displaced
volume (cm³)
the displaced volume measured as following:
Displaced volume (cm³) = Final reading –
Initial reading
Final reading & Initial reading ( from
trial )
Procedures :
1-We
filled the flask with kerosene to a
point on the stem between the o and the 1 mL mark. Dry the inside of the
flask
above the level of the
liquid .
2- Then we put the
flask and immersed it in a constant water bath
for sufficient period of time in
order to avoid flask temperature variation above (0.2 ºc) before recording the
first reading .
3-We measured (64 g)
of Portland cement and introduced it at the same temperature as
the liquid, in small increment (Taking care to avoid splashing and see that the
cement doesn't adhere to the inside of the flask above the liquid ).
4-After
we put all the cement , and placed the stopper in the flask and rolled the
flask in an inclined position, so as to free the cement from air until no
further air bubbles rise to the surface of the liquid.
5-record the last
reading after immersing the flask and its contituents in the constant
temperature water bath.
Results &
Calculation :
)
Density Of Hydraulic
cement
|
S
|
Difference %
|
Cement density
(g/cm³)
|
Displaced volume
(cm³)
|
Final reading (mL)
|
First reading (mL)
|
Weight of cement
|
sample
|
|
3.2
|
|
3.2
|
19.95
|
20.5
|
0.55
|
64
|
1
|
|
2.9
|
7.94
|
2.9
|
23
|
24
|
1
|
64
|
2
|
Samples of
calculations
1. ρ =mass / Volume
2. Difference
% = ( { ρ theo – ρ exp } / ρ theo) *100
Where :-
= theoretical value of
the cement density 3.15 gm/cm3 ρ theo
3. specific gravity (unitless) = ρsub / ρ H25
ρsub :- density of cement
ρ H25 :- Water Desity = ( 1 g/cm3) = 1000 kg /m3 at 4 C0
Note
ml = cm3
Sample No. 1
The Volume = Final Reading
The Volume =
20.5– 0.55
= 19.95cm³
Cement Density =The mass of cement / The volume of cement
Cement Density = 64 / 19.95
= 3.2
g/ cm³
Difference % = (
{ ρ theo – ρ exp } / ρ
theo) *100
Difference % = ({3.15-2.9}/3.15)
* 100 = 7.94%
specific gravity = ρsub / ρ H25
= 2.9/1 = 2.9
Conclusion :
We can note that these
results is closed together, and so we can consider these results goes to the
real value of density
of this type of
Pozolana Portland Cement Type II/A
Discussion :
1-The variation of temperature is the very
important factor in the density of cement trial , because of the expanding of
the kerosene .
2- The moisture in cement
or in kerosene is another important factor in this trial .
3- May be there is some air bubbles in the flask didn’t come Out of it .
Sources of Errors :
1-Human error .
2-Instrument error .
3-Error in putting
cement in Le Chatelier Flask .
4-Error as result of
moisture in cement .
References :
1- Materials Of
Construction Lab Manual .
2-
Lecture by Eng.
