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Table of Contents
Introduction: ........................................................................................................................................................................ 2
Experiment No. (AGG. 1) ...................................................................................................................................................... 3
Purpose: ........................................................................................................................................................................... 3
Apparatus: ....................................................................................................................................................................... 3
Sampling Methods: .......................................................................................................................................................... 4
Experiment No. (AGG. 2) ...................................................................................................................................................... 6
Purpose: ........................................................................................................................................................................... 6
Apparatus: ....................................................................................................................................................................... 6
Procedures: ...................................................................................................................................................................... 7
Data Sheet & calculations &Graph .................................................................................................................................. 8
Conclusion: .................................................................................................................................................................... 10
Some Photos: ................................................................................................................................................................. 11
Experiment No. (AGG. 3) .................................................................................................................................................... 12
Definition: ...................................................................................................................................................................... 12
Apparatus: ..................................................................................................................................................................... 12
Procedure ...................................................................................................................................................................... 12
Experiment No. (AGG. 4) .................................................................................................................................................... 13
Definition: ...................................................................................................................................................................... 13
Apparatus: ..................................................................................................................................................................... 13
Procedure: ..................................................................................................................................................................... 13
Experiment No. (AGG. 5) .................................................................................................................................................... 14
Purpose: ......................................................................................................................................................................... 14
Part One: The Coarse Aggregates Experiment: .............................................................................................................. 14
Apparatus: ..................................................................................................................................................................... 14
Procedure: ..................................................................................................................................................................... 14
Data Sheet & calculations: ............................................................................................................................................. 15
Part Two: The Fine Aggregates Experiment: .................................................................................................................. 16
Apparatus: ..................................................................................................................................................................... 16
Procedure: ..................................................................................................................................................................... 16
Data Sheet & calculations: ............................................................................................................................................. 17
Conclusion( for Exp.5): ................................................................................................................................................... 17
Some Photos: ................................................................................................................................................................. 18
Resources: .......................................................................................................................................................................... 20
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Introduction:
The aggregates normally used for concrete are natural deposits of sand and gravel, where available.
In some localities, the deposits are hard to obtain and large rocks must be crushed to form the
aggregate. Crushed aggregate usually costs more to produce and will require more cement paste
because of its shape. More care must be used in handling crushed aggregate to prevent poor mixtures
and improper dispersion of the sizes through the finished concrete. At times, artificial aggregates,
such as blast-furnace slag or specially burned clay, are used.
Types of Aggregates( Based on Size ):
1- Fine Aggregates :
Fine aggregate is defined as material that will pass a No. 4 sieve and will, for the most part, be
retained on a No. 200 sieve such as the sand. For increased workability and for economy a reflected
by use of less cement, the fine aggregate should have a rounded shape. The purpose of the fine
aggregate is to fill the voids in the coarse aggregate and to act as a workability agent.
2- Coarse Aggregates:
Coarse aggregate is a material that will pass the 3-inch screen and will be retained on the No. 4
sieve such as crushed stones. As with fine aggregate, for increased workability and economy as
reflected by the use of less cement, the coarse aggregate should have a rounded shape. Even though
the definition seems to limit the size of coarse aggregate, other considerations must be accounted for.
When properly proportioned and mixed with cement, these two groups yield an almost void less
stone that is strong and durable. In strength and durability, aggregate must be equal to or better than
the hardened cement to withstand the designed loads and the effects of weathering. It can be readily
seen that the coarser the aggregate, the more economical the mix.
Types of Aggregates( Based on Source ):
1- Natural aggregates: natural aggregates are derived from the rocks such as granite, Limestone.
2- Artificial Aggregates may be: Byproducts of industrial Process (Blast-furnace slag) or Special
Products to manufacture light weight aggregates from Clay, Shale, Shell.
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Experiment No. (AGG. 1)
Sampling of Aggregates
Purpose:
In this experiment we are going to reduce the sample size of the aggregate several times to
make the testing easily. Also to ensure that the quality of the reduced sample is
representative of the original sample.
Apparatus:
Riffle Box Stick
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Shovel Brush Blanket or sheet.
Sampling Methods:
There are two methods for sampling the aggregates:
1. The mechanical splitter (Riffle box): The mechanical splitter is a method that divides the sample of aggregates into two equal
parts. It has at least 8 channels for the coarse or combined aggregate and 12 for the fine
aggregates. The size of each channel is not less than 1.5 times the size of largest
aggregate particle. The splitter should be on a level surface to make sure that each part
of the samples has the same size.
Procedures:
1. Place the catch pans in the right place under the splitter so that all of the particles
diverting in both directions will be caught and nothing will be out.
2. Place the sample of aggregates in the hopper and uniformly distribute it from
edge to edge so that approximately equal amounts flow through each channel.
3. Remove the catch pans and repeat the procedure several times to split the first
part until you obtain the required sample size.
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2. Method of quartering:
Procedures:
1. Place the sample of aggregates on a clean blanket or sheet.
2. Mix the sample using a shovel for at least three times.
3. Lift each corner of the sheet and pulling it over the sample toward the diagonally
opposite corner, causing the material to be rolled. With the last turning, form a conical
pile.
4. Flatten the pile to a uniform thickness and diameter by pressing with a shovel. The
diameter should be 4-8 times the thickness.
5. Insert a stick or pipe beneath the sheet and under the center of the pile, then lift both
ends of the stick, dividing the sample into two roughly equal part. Remove the stick
then Insert it under the center of the pile at right angles to the first division and again
lift both ends of the stick, dividing the sample into four roughly equal quarters.
6. Remove two diagonally opposite quarters, and clean the fines from the sheet using the
brush.
7. Mix the remaining quarters and repeat the steps to get the required sample size.
Mixing the sample using shovel. Flatten the pile
Dividing the sample into four quarters using a stick.
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Experiment No. (AGG. 2)
Sieve Analysis of Aggregates
Purpose:
To find the size of particles in a sample of coarse and fine aggregates using sieves and to draw the grading graph.
Standards
The procedure follows that given in BS 812 : Part 103.1: 1985, BS 882 : 1992 and ASTM C136 - 84.
Apparatus:
Sieves according to ASTM
Mechanical sieve shaker Balance Brush
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Procedures:
1. Dry the aggregate sample to constant weight at a temperature of 110 ˚C, then weigh it
to the nearest 0.1 g.
2. Select sieves with suitable sizes (according to ASTM or BS ) and place them from the
largest at the top to the smallest at the bottom, and make sure that the sieves are
clean.
3. Place the sample on the sieves at the top then close the sieves.
4. Place the sieves in the mechanical shaker and run it for at most 10 min.
5. Remove the sieves from the mechanical shaker and weigh the mass of sample retained
in each sieve using the balance (its better to shake the sieves by hand before weighing
it) .If the total weight differs by more than 3%, based on the original dry sample mass,
the results should not be used for acceptance purposes.
6. Calculate the percentage retained on each sieve and the cumulative percentage
passing each sieve size to the nearest whole number.
7. Draw the grading graph (using log scale) then use ASTM limits to identify your
sample.
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Data Sheet & calculations
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Grading Graph
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Conclusion:
FM=(cumulative % retained on sieves No.100,No.50,No.30,No16,No.8,No.4)/100
=(94+89+86+82+75+63)/100 = 4.89
After doing the calculations we obtained a Fineness Modulus (FM) equals to ( 4.89 )
with error of 0.4% which is acceptable.
By comparing our results with the ASTM standards (C33) we found the our results
doesn’t match with the standards, so we need to make some changes in our sample of
aggregates to make it within the standard limits.
Sources of error:
1) Personal Errors:
- Errors in doing the calculations (% retained, cumulative % retained, FM, …etc).
- Dealing with equipments and materials in a wrong way , for example:
Error in using the balance (if the balance was not at zero before
weighing the materials).
2) Random Error:
- Change in the laboratory temperature.
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Some Photos:
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Experiment No. (AGG. 3)
Flakiness Index (coarse Aggregates)
Definition:
A particle is flaky if the thickness of the particle (the smallest dimension in the paticle) is less than
0.6 of mean sieve size it retains on.
The flakiness index of an aggregate sample is found by separating the flaky particles and expressing
their mass as a percentage of the mass of the sample tested
Limitations:
This test is applicable only for particles, which have nominal aggregate size between 6.3
and 63 mm provided that each portion lies between two test sieves participating for not
less than 5% of the total weight of test sample.
Apparatus:
Thickness Gauge. Flakiness sieves
Procedure
1. Carry out sieve analysis test wet (for conglomerated particles) or dry.
2. Weigh each of the individual size-fractions retained on the sieves and store in
separate containers.
3. Record the sum of the masses fractions in containers as M1.
4. Calculate the individual percentage retained (comparing to M1).
5. Discard any fraction whose mass is less than 5% of M1 and record the remaining
masses sum as M2.
6. Gauge each fraction using flakiness gauge or flakiness sieves.
7. Combine and weigh all particles passing each gauge and record the sum as M3.
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Experiment No. (AGG. 4)
Elongation Index (coarse Aggregates)
Definition:
A particle is elongated if the length of the particle (the greatest dimension) is more than 1.8 of their
mean sieve size it retains on.
The elongation index is found by separating the elongated particles and expressing their mass as a
percentage of the mass of the sample tested.
Limitations:
This test is applicable only for particles, which have nominal aggregate size between
6.3 mm and 50 mm provided that each portion lies between two test sieves participating for
not less than 5% of the total weight of test sample.
Apparatus:
Metal length gauge
Procedure:
1. Carry out sieve analysis test (wet or dry).
2. Weigh each of the individual size fractions retained on the sieves and store in
separate containers.
3. Record the sum of the masses fractions in containers as M1.
4. Calculate the individual percentage retained (comparing to M1).
5. Discard any fraction whose mass is less than 5% of M1 and record the remaining
masses sum as M2.
6. Gauge each fraction using elongation gauge.
7. Combine and weigh all particles retained on each gauge and record the sum as M3.
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Experiment No. (AGG. 5)
Determination of Particle density and
water Absorption of aggregates
Purpose:
To determine the particle density and water absorption of fine and coarse aggregate.
This Experiments is divided into two parts:
1) The Coarse Aggregates Experiment.
2) The Fine Aggregates Experiment.
Part One: The Coarse Aggregates Experiment:
Apparatus:
1- A balance having capacity of at least 3 kg, readable to 0 .5g.
2- An oven, thermostatically controlled to maintain a temperature of 105+/-50
C.
3- A wire basket. 4- A towel.
5- A shallow tray.
Procedure:
a) Specimen preparation :
1. Take 2kg of the sample.
2. Wash the sample in 10 mm sieve to remove the finer particles. 3. Drain the sample.
b) Test procedure :
1. Place the prepared specimen in the wire basket and immerse in water.
2. Remove the air from the sample by lifting the basket and dropping it with the content 25 times.
3. Leave the basket with content immersed for 24hrs +0.5hr.
4. Weigh the basket and specimen in water at 200
C +50
C and record the mass (A).
5. Remove the basket from water and allow to drain for a few minutes. 6. Empty the sample from the basket on a towel and dry the sample using that towel
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until the surface of the aggregate becomes dry. 7. Return empty basket to the water, weigh it in water at the same level. 10. Weigh the aggregates mass in S.S.D (saturated surface dry) condition.
11. Dry the sample in the oven at temperature of (105+5)0
C for 24 hours.
12. Cool the sample then weigh it and record the results (oven dry weight).
Data Sheet & calculations:
1) Data sheet (Next page).
2) Calculations:
- Particle density on an oven-dried basis =[ D/ (B-C) ] = [2089.0/ (2098.5-1381.9) ]
=2.915 ≈ 2.92 Mg/m3
- Particle density on a saturated and surface-dry basis = [ B/ (B-C) ] = [2098.5/(2098.5-
1381.9) ]=2.928 ≈ 2.93 Mg/m3
- Apparent particle density =[D/ (D-C)]=[2089.0/(2089.0-1381.9)]= 2.954 ≈ 2.95 Mg/m3
- Water Absorption by % of Dry Mass = [ 100*(B-D)/D ] =
[100*(2098.5-2089.0)/2089.0]= 0.454 ≈ 0.5 %
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Part Two: The Fine Aggregates Experiment:
Apparatus:
1- Balance having capacity of at least 3Kg, readability to 0.5g.
2- An oven.
3- Pyknometer of capacity 500 ml .
4- Dryer.
5- Metal mold.
6- Tamper.
Procedure:
a) Specimen preparation:
1. Take 0.5 kg of fine aggregates of 5mm nominal size (dune sand)
2. Wash sample thoroughly on sieve 75micron, as follow: - Place the sample in container and cover it with water and pour it over the sieve. The 75 micron sieve should be protected by a larger sieve during the washing process.
- Retained materials on the sieves must be returned to the sample.
b) Test procedure
1. Transfer washed sample to the tray and immerse with water.
2. Gently agitate the sample with a rod to remove the bubbles of air.
3. Keep sample immersed in water for 24 hours at 20o
C.
4. Drain the water from the sample using a 75 micron sieve. 5. Use the dryer to expose warm air to dry the surface moisture. 6. Check the dryness using the conical mold by filling it with the sample then
dropping the tamper in the mold for 25 times and remove the conical to check the shape of the sample. Repeat this until getting a shape with a complete collapse of a definite peak (not over-dried surface).
7. Weigh the S.S.D (saturated surface dry) sample.
8. Place the aggregates in the pyknometer and fill it with water. 9. Screw the cone, refill to the top, eliminate air bubbles and clean the outside.
10. Take the total weight.
11. Empty the sample into the tray.
12. Refill the pyknometer with water to the same level and weigh it.
14. Dry the sample using the oven at 105o
C +5o
C for 24 hours.
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15. Cool the sample to room temperature and record the weight (oven dry weight).
Data Sheet & calculations:
3) Data sheet (Next page).
4) Calculations:
- Particle density on an oven-dried basis =[ D/ (B-C) ] = [435.8/ (442.2-273.3) ] = 2.58
Mg/m3
- Particle density on a saturated and surface-dry basis = [ B/ (B-C) ] = [442.2/(442.2-
273.3) ]=2.618 ≈ 2.62 Mg/m3
- Apparent particle density =[D/ (D-C)]=[435.8/(435.8-273.3)]= 2.68 Mg/m3
- Water Absorption by % of Dry Mass = [ 100*(B-D)/D ] =
[100*(442.2-435.8.0)/435.8]= 1.468 ≈ 1.5 %
Conclusion( for Exp.5):
After doing our experiment, and doing the calculation we determined the density of the
particles and the water absorption for the coarse and fine aggregates.
Also we noticed that the water absorption for the fine aggregates (1.5 %) is greater than the
absorption for the coarse aggregates(0.5 %).
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Some Photos:
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Resources:
1- Materials for civil Engineering - Lab Manual.
2- http://www.tpub.com/content/engineering/14070/css/14070_287.htm
3- http://www.in.gov/indot/files/T_248_aashtoB.pdf
4- http://www.in.gov/indot/files/CHAPTER3_InspAggregate.pdf
5- http://itd.idaho.gov/manuals/Online_Manuals/Current_Manuals/QA%2
0Manual/July_07/FOPs/T248_short_wpr.pdf
6- ASTM Standard C33.
