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Title:
Testing of Aggregates II
Series:
Concrete Materials and Mix Sub-Series
Produced by:
Human Resource Training and Materials
Development Division, AMMS
Date:
March 2003
Opening course title
PART II
* Effect of Organic Impurities in Fine
Aggregates on Strength of Mortar
* Soundness of Aggregates by use of
Sodium Sulfate or Magnesium
Sulfate
* Unit Weight/Mass Determination of
Aggregates
* Abrasion of Coarse Aggregates by
use of the Los Angeles Machine
4th test : Effect of Organic Impurities in
Fine Aggregates
EFFECT OF ORGANIC
IMPURITIES IN FINE
AGGREGATES ON
STRENGTH OF MORTAR
Determines acceptability
of Fine Aggregates
Apparatus needed : Flow table
Tamper
Trowel and molds
Water storage
Compression machine
Cement samples
Test procedures: Prepare samples
Wash original sample with water
Wash sand with Sodium Hydroxide
Soak two samples in water
Spread sample in flat surface
Place sample in mold
Prepare water cement ratio
Mix the materials
Pour sand to cement paste
Determine the flow
Remove excess mortar
Lift mold
Drop flow table
Place mortar in cube molds
Fill the mold
Smoothen surface
Remove the sample
Test for compressive strength
Prepare standard mortar
Compare compressive strength
Age in days
7
7
7
Average
Sample
5.1
5.1
5.1
5.1
% of Standard – 100%
Standard
5.0
5.1
5.1
5.1
5th test : Soundness of Aggregates
SOUNDNESS of AGGREGATES by
use of SODIUM SULFATE or
MAGNESIUM SULFATE
• Determines the aggregate
resistance to disintegration by
saturated solutions
Apparatus needed: Set of sieves
Balance
Perforated containers
Oven
Solvents
Wash samples
Separate fine aggregates
PASSING RETAINED
(Fine Aggregates)
9.5
4.75
4.75
2.36
2.36
1.18
1.18
0.600
0.600
0.300
1009
1009
1009
1009
1009
Separate coarse aggregates
PASSING RETAINED
(Coarse Aggregates)
63.5
37.5
37.5
19.0
19.0
9.5
9.5
4.25
30009
15009
10009
3009
Prepare a saturated solution
Immerse sample in solution
Remove samples
Wash with water
Pass to original sieve
Weigh
Formula : Loss in mass
Loss in Mass = Mass of test
fraction before
test MINUS Mass
of test fraction
after test
Formula : Actual % loss
Actual %
=
Loss
Loss in Mass
Mass of test
fraction before
test
Formula :Corrected % Loss
Corrected
=
% Loss
% passing
sieve after test
Grading of Original
sample, % retained
6th test : Unit Weight in Aggregates
UNIT WEIGHT or MASS
DETERMINATION in
AGGREGATES
- Determines the unit weight
of aggregates in a compacted
or Loose condition
Apparatus needed: Balance and
weights
Tamping rod
Cylindrical metal measure
Shovel
Formula : Volume of Container
Volume of
Container
Mass of
water
=
Unit mass of Water
at Temperature of
Calibration
Prepare sample
Mass Determination
RODDED Unit Weight or Mass
Determination
Fill 1/3 portion of measure
Level and tamp
Fill 2nd portion of measure
Fill last third portion of measure
Remove excess aggregates
Weigh container with aggregates
Formula : Rodded Unit Weight
RODDED
UNIT
WEIGHT
=
Net weight of
aggregates
Volume of the
measure
Loose Unit Weight
Formula : Loose Unit Weight
LOOSE
UNIT
=
WEIGHT
Net
weight of
sample
Volume of
container
7th test : Abrasion of Coarse
Aggregates
ABRASION of COARSE
AGREGGATES BY USE of the
LOS ANGELES MACHINE
Evaluate the structural
strength of course aggregates
Apparatus needed : Los Angeles
machine
Abrasive charges
Pans and sieves
Balance
Oven
Test samples
Place sample in machine
Discharge materials after test
Sieve finer portion
Wash materials and dry
Weigh
Formula : % Abrasion Loss
a–b
x 100
% Abrasion Loss = a
where:
a=
original weight/mass of
sample
b=
weight / mass of Materials
coarser than 1.70 mm
sieve size
Closing course title
CONCRETE MATERIALS AND MIX SUB SERIES
TESTING OF
AGGREGATES
Part II
The End
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Produced by
Produced by
Human Resource Training and
Materials Development Division
AMMS