View
13
Download
0
Category
Tags:
Preview:
DESCRIPTION
This is the lab report of the Specific Gravity and Water Absorption of Fine aggregate which the experiment carried out by student in construction material course in the department of Civil Engineering from Zaman University, Cambodia.
Citation preview
0
Construction Materials
Laboratory Report 1 Testing for Specific Gravity and Water Absorption of Fine Aggregate
ZAMAN UNIVERSITY
2013-‐2014
Professor: Bun Kim Ngun
Student’s Name: Mengheng LIM
Experiment on 23rd of November 2013
Laboratory Report 1 Testing for Specific Gravity and Water Absorption of Fine Aggregate
Page | 1
Content
Page
I. Objective of the experiment: ................................................................................. 2
II. Introduction ........................................................................................................... 2
III. Materials and Tools ............................................................................................ 3
IV. Procedures: .......................................................................................................... 4
V. Data ......................................................................................................................... 5
VI. Calculation ........................................................................................................... 6
VII. Conclusion ........................................................................................................... 8
VIII. References ......................................................................................................... 10
Laboratory Report 1 Testing for Specific Gravity and Water Absorption of Fine Aggregate
Page | 2
Testing for Specific Gravity
and Water Absorption of Fine Aggregate
I. Objective of the experiment:
In this experiment we want to find the specific gravity and water absorption of fine
aggregates which has been place in water for 24h and after it has been dry up in the
oven. For this experiment, we based on the ASTM C128 standard method and carries
out three different separate tests for more accurate result. This experiment will also
helped us to determine and discuss about the different values due to the errors and
some other factors that has been affected during the process.
II. Introduction
• Specific Gravity is the characteristic that mostly used for calculation for
volume occupied by the aggregate in various mixtures that contain aggregate
such as Portland cement concrete, bituminous concrete, and other mixtures that
are proportioned or analyzed on an absolute volume basis.
• Water Absorption values are widely for calculation of the proportional different
mass of an aggregate as the water is absorbed in the pore spaces within the
constituent particles, compared with dry condition, when it is deemed that the
aggregate has been in contact with water long enough to satisfy most of the
absorption potential.
• These two values are very important to engineers when building structures high
humidity atmosphere and the place where there are a huge different in humidity
daily or monthly. It helps engineer to determine the correct amount of the fine
aggregate during the mixture process so that they can get the better quality for
their concrete. Moreover, before the structures have been finished, this values
must be take into account for calculate the total weight and expansion of the
structures when there are different in humidity in the atmosphere.
Laboratory Report 1 Testing for Specific Gravity and Water Absorption of Fine Aggregate
Page | 3
III. Materials and Tools
a. Sample:
• Fine Aggregate: it must be place in the tap water for at least 24h to
make sure that all of its pores has been filled with water. 1kg of fine
aggregate (weight before place in the tap water) is needed to carry out
3 separate tests.
b. Apparatus:
1) Balance with 0.1g precise
2) 250ml volumetric flasks and funnel
3) Conical mold and Tamper
4) Metal pans
5) Drying oven
6) Heat gun
7) Small metal shovel
Laboratory Report 1 Testing for Specific Gravity and Water Absorption of Fine Aggregate
Page | 4
IV. Procedures:
1. Use the metal shovel to take out the sand from the wet sand container and place it
on a metal pan about 1.5 inner-volume of conical mold.
2. Use heat gun to dry the surface of the wet fine aggregate to get saturated-surface-
dry aggregate (SSD) and also mix during drying
ü Make sure that it is not too hot as we need only its surface to dry
3. Then use the Conical mold to test whether the fine aggregate surface it dry or not.
Place the Conical mold on the metal pan then put the aggregate inside with small
pressure until it is full. Use tamper to drop on the top of the mold 25 times with
the height 5mm above the mold. Finally, remove take the mold up vertically and
slowly. Then if the aggregate remain in the shape, it means that the aggregate still
has a wet surface, but if the top aggregate has been fallen down a bit, then it can
be used as the saturated surface dry sample.
4. Use the balance to weight SSD about 200g ±10g and mark as S
5. Then put SSD into the 250ml volume metric flask with the help of funnel. Then
put the water inside and shake it gently until there is no bubble coming out which
mean there is no space between each particle. Add more water to the 250ml notice
line.
6. Clean out any wet water outside the volume metric flask and then use the balance
to measure its weight get mark as C
7. Take out those aggregate and place it into the metal pan, use additional water to
help removing aggregate particles. After that, pour the water out of the metal pan
as much as possible.
8. Fill that empty flask with only tap water again and then use balance to measure
the weight and mark as B
9. Place the aggregate in the metal pan into the drying oven for 24H with the
constant temperature of 115oC to get the oven-dry aggregate
10. Use balance to weight the oven-dry aggregate and mark as A
v Repeat this process for 3 times
Laboratory Report 1 Testing for Specific Gravity and Water Absorption of Fine Aggregate
Page | 5
V. Data
A: Oven-dry weight
B: Weight of empty flask filled with tap water
C: Weight of flask with aggregate filled with tap water
S: Weight of saturated surface dry aggregate
1st Experiment
A1 197.3g
B1 342.8g
C1 465.8g
S1 200.8g
2nd Experiment
A2 193.6g
B2 345.3g
C2 468.3g
S2 200.2g
3rd Experiment
A3 196.2g
B3 353.8g
C3 479.0g
S3 201.4g
Laboratory Report 1 Testing for Specific Gravity and Water Absorption of Fine Aggregate
Page | 6
VI. Calculation
Specific Gravity of Saturated Surface Dry Fine Aggregate
SSG(SSD) =B+S -C�
Specific Gravity of Oven Dry Fine Aggregate
ASG(OD) =B+S -C
Water Absorption of Fine Aggregate
S - AWA (%) = ×100A
First Experiment
200.8( )342.8 200.8 465
2.5809.8
SG SSD = =+ −
197.3( )342.8 200.8 465.8
2.5359SG OD = =+ −
200.8 197.3(%) 100 1.77%197.3
WA − = × =
Second Experiment
200.2( ) 2.5932345.3 200.2 468.3
SG SSD = =+ −
193.6( )345.3 200.2 468.3
2.5077SG OD = =+ −
200.2 193.6(%) 100 3.41%193.6
WA − = × =
Third Experiment
201.4( ) 2.6430353.8 201.4 479.0
SG SSD = =+ −
196.2( )353.8 201.4 479.0
2.5748SG OD = =+ −
201.4 196.2(%) 100 2.65%196.2
WA − = × =
Laboratory Report 1 Testing for Specific Gravity and Water Absorption of Fine Aggregate
Page | 7
Average Result:
2.5809
2.5359 2.507
2.5932 2.6430( ) 2.60573
( ) 2.53943
1.77 3.41 2.6
7 2.57
5(%)
48
2.61%3
avg
avg
avg
SG SSD
SG OD
WA
+
+ +
+= =
= =
+ + = =
Standard Deviation:
( )
( )
(%)
SG SSD
SG OD
WA
δδδ
= 0.0268
= 0.0275
= 0.6701
The table shows the overall summary of the result:
1st Experiment
2nd Experiment
3rd Experiment
Average Standard Deviation
SG (SSD) 2.5809 2.5932 2.6430 2.6057 0.0268
SG (OD) 2.5359 2.5077 2.5748 2.5394 0.0275
WA (%) 1.77% 3.41% 2.65% 2.61% 0.6701
Laboratory Report 1 Testing for Specific Gravity and Water Absorption of Fine Aggregate
Page | 8
VII. Conclusion
According to the result from our experiments,
The average of Specific Gravity of Saturated Surface Dry Fine Aggregate is 2.6057.
The average of Specific Gravity of Oven Dry Fine Aggregate is 2.5394.
The water absorption rate of the fine aggregate is 1.77%, 3.41%, 2.65%
Discussion: Although the result of SG of SSD and OD for each experiments are close to each
other’s, but there are a huge different in result of Water Absorption and has the
standard deviation up to 0.67. So the overall result of this experiment should not be
trusted or used this result for practical purpose. The experiment went wrong might be
due to:
• The sample fine aggregate that we used as the sample is not pure fine aggregate,
but there are some dust (diameter < 75µm) that mixed with aggregate.
• The sample was continuously lose during the process, which we cannot make sure
that all of the sample will be transferred from one container to another container
and also amount of sample lose for each experiment is not the same.
• Furthermore, at the stage of Saturated Surface Dry (SSD), the drying surface rate
of the three samples are not the same.
• On the other hand, there are also other factors that affect our experiments such as
eye-level error during the volume of water in the volumetric flask.
The test is recommended for carry out the new experiment and might also have to
improve the efficiency but trying to minimize above factors that affect the result. Some
improvement methods are:
• Wash the sample to remove all dust (diameter < 75µm) before use. It can be used
the sieving method with the sieve number 200.
• Minimize the loss of the sample while trying to transfer from one container to
another container.
• Use Pycnometer instead of volumetric flask as it can decrease the eye level error
and also decrease the rate of transferring the sample from volumetric flask to other
container.
Laboratory Report 1 Testing for Specific Gravity and Water Absorption of Fine Aggregate
Page | 9
• Make sure that there should not be a big different rate of SSD, by each time try to
measure the amount of wet aggregate taken out and time to dry to be similar.
More importantly make sure the level of distribution of sample in the conical
mold process should be the same or similar. And do not place the sample without
any covering of cloth is it is not being used or pause in any cases.
Laboratory Report 1 Testing for Specific Gravity and Water Absorption of Fine Aggregate
Page | 10
VIII. References
1. “Basic Construction Materials” by Theodore Marotta, John C. Coffey, Cynthia
LaFleur-Brown, Christine LaPlante. 8th Ed. Pearson 2010.
2. ASTM C0128-04A Test Method for Density, Relative Density (Specific Gravity), and
Absorption of Fine Aggregate
3. FINE AGGREGATE DENSITY TESTING, WHATIS THE RIGHT WAY TO DO
IT? By Chris Rogers and Tom Dziedziejko
Recommended