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UNESCO-NIGERIA TECHNICAL &
VOCATIONAL EDUCATION
REVITALISATION PROJECT-PHASE II
YEAR 2- SE MESTER 2
PRATICAL/
Version 1: December 2008
NATIONAL DIPLOMA IN
CIVIL ENGINEERING TECHNOLOGY
INTRODUCTION TO HIGHWAY
ENGINEERING
COURSE CODE: CEC 204
2
Table of Contents
WEEK 1 Standard Flakiness and Elongation Test
WEEK 2 Aggregate Crushing Value (ACV) Test
WEEK 3 Aggregate Impact Value (AIV) Test
WEEK 4 Hardness Test
WEEK 5 Viscosity Test
WEEK 6 Flash and Fire Points Test
WEEK 7 Ductility Test
WEEK 8 Softening Point (Ring and Ball Test)
WEEK 9 Stability and Flow Test (Marshall)
WEEK 10 Hubbard Field Test
WEEK 11 Design Mix of Plastic Concrete
WEEK 12 Design of Trial Mix of Plastic Concrete
WEEK 13 Stability Test (Hveem Stabilometer)
WEEK 14-15 Site Visit
3
INTRODUCTION TO HIGHWAY ENGINEERING PRATICAL
INTRODUCTION
The properties of most importance in a road making aggregate are its resistance to crushing,
impact, abrasion and polishing, it s specific gravity and water absorption and its grading and
particle shape.
As aggregate obtained from different sources differ considerably in their constitution and
properties, inevitably they differ also with their engineering properties. It is necessary
therefore, to carry out various tests on aggregates to ensure not only that undesirable
materials are excluded from highway pavements but also that the best available aggregates
are included.
Also for bitumen and tars, the most careful specifications with regard to the design and
construction of a bituminous road surfacing are of little value if the properties of the
bituminous binder used in the design are not adequately controlled. To ensure that the
material obtained has the desired qualities, a number of tests have been devised which
attempts to measure various binder properties for particular reasons.
4
WEEK I AGGREGATES (BS 812)
EXPERIMENT NO.1: STANDARD FLAKINESS AND ELONGATION TESTS
AIM: To determine the Flakiness and Elongation indices of a sample
of aggregate.
APPARATUS: 1. A thickness gauge and a length gauge
2. A 3kg balance
3. One set of sieves of sizes: 63.5mm, 50. 8mm, 38.1mm,
254mm, 19.05mm, 12.7mm, 9.52mm and 6.35mm
4. A shallow tray.
THEORY: A flaky particle has thickness (least dimension) less than 0.6
times the mean size of the fraction to which the particle
belongs. An elongated particle has length which is more than
1.8 times the mean sieve size of the sieve fraction to which the
particle belongs. The content of elongated or flaky particles in
excess of 10 to 15 percent of the weight of coarse aggregate is
generally considered undesirable.
PROCEDURE: 1. Sieve a sufficient but known quantity of coarse aggregate to
Provide a minimum of 200 pieces on each of the above sieves.
2. Separate the flaky material of each fraction by “placing” on the
thickness gauge and determine the total weight in the
appropriate slot of material.
3. Weigh the total amount of material passing the gauge to an
accuracy of at least 0.1% of the weight of the test sample.
4. Repeat, using the length gauge.
RESULTS: Report the flakiness index as the total weight of material
passing the various thickness gauges expressed as a percentage
5
of the total weigh of the sample gauge to the nearest whole
number. Obtained also the elongation Index.
CONCLUSION: Comment on your results and state their compliance or
otherwise with standard values.
REFERENCE: BS 882
6
WEEK 2
AGGREGATES (BS 812: Part 3)
EXPERIMENT NO.2: DETERMINATION OF AGGREGATE CRUSHING
VALUE (ACV)
AIM: To determine the aggregated crushing value of a sample of
coarse aggregate.
APPARATUS: 1. A 152mm dia open- ended steel cylinder with plunger and
base plate.
2. A tamping rod of 9.5mm dia and 609.6mm long.
3. A 3kg balance
4. A set of B.S test sieves of sizes: 12.7mm, 9.5mm and 2.0mm.
PROCEDURE: 1. Sieve the aggregate sample to pass through sieve size
21.7mm and retained on the B.S sieve 9.5mm.
2. Prepare sufficient aggregate for tests (about 5 kg) and ensure
that it is in a clean and surface dry condition (according to
standard requirement, it should be oven –dried, 100 – 110oC).
3. Place the cylinder on the base plate and fill with the aggregate
in three equal layers giving 25 blows to each layer.
4. Level off the top of the aggregate with the tamping rod and
weigh (weigh A). Insert the plunger so that it just rests
horizontally on the surface of the aggregate.
5. Test sample in the compression machine loading at 40 KN/min
to a load of 400 KN (10 minutes).
6. Remove the material from the cylinder and sieve of a 2.40mm
B.S test sieve.
7. Determine the weight of the fines passing the 2 sieve (weight
B) and express this as a percentage the total weight of
aggregate used as shown in the calculation below.
7
CALCULATIONS: Aggregate crushing value = B x 100
A
RESULTS: Report the mean of the two values to the nearest number.
Permissible crushing value is as for impact test.
CONCLUSION: Comment on your results and compare with the permissible
values.
REFERENCE: BS 882
8
WEEK 3 AGGREGATES (BS 812: Part 3)
EXPERIMENT NO.3: DETERMINATION OF AGGREGATE IMPACT VALUE
AIM: To determine the impact of a sample of coarse aggregate.
APPARATUS: 1. An aggregate impact testing machine complete with standard
cylindrical measure of 76.2mm dia and 50.8mm high and
tamping rod of 9.5mm dia and 228.6mm long.
2. A set of B.S test sieves: 12.7mm, 9.52mm and 2.40mm.
3. A 3kg balance
THEORY: The impact value is expressed as percentage of fines passing
the 2.40mm sieve (to the nearest who le number) to total weight
of the sample. The permissible AIV is 45% for ordinary
concrete used for wearing surfaces
.
PROCEDURE: 1. Prepare a sample of the coarse aggregate which passes
The 12.7mm sieve and is retained on the 9.52mm sieve.
2. Prepare sufficient aggregate for two tests and ensure that it is in
a clean and surface dry condition.
3. Fill the 76.2mm dia cylinder in three equal layers giving 25
strokes of the 22.9cm metal tamping rod to each layer.
4. Level off the top of the aggregate to the nearest gram and use
the same weight of material for each test (weight A).
5. Place the whole of the sample in the cup, fix firmly in position
on the base on the impact machine, and apply 25 blows of the
tamping rod.
6. Subject the sample to 15 blows by allowing the hammer of the
machine to fall freely.
7. Sieve the crushed aggregate on a 2.40mm sieve and determine
the percentage passing by weight (weight B).
CALCULATIONS: Aggregate impact value = B x 100
9
A
RESULTS: Report the mean of the two tests.
CONCLUSION: Comment on your results by comparing them with the standard
values.
REFERENCE: BS 882
10
WEEK 4
EXPERIMENT NO.4 HARDNESS TEST (ABRASION TEST)
AIM: To determine the hardness of a sample of aggregate.
APPARATUS: Los Angeles Abrasion machine weighing balance, 1.7mm
sieve.
THEORY: The top layers of a pavement get abraded due to the movement
of tires. A material which is highly abrasion resistance has a
long life. The test has been standardized as ASTM-C 131 and
AASHTO –T 96.
PROCEDURE: 1. Weigh 5kg dried of test sample.
2. Place the weighed sample into the steel cylinder along with the
required steel balls.
3. Rotate the cylinder at a speed of 30 -33 revolutions/minute for
500 – 1000 revolutions (depending on the material).
4. Remove the material
5. Pour into 1.7mm sieve
6. Weigh the material that passes through 1.7mm
RESULT: Report the weight of this material (fines) as a percentage of the
total weight of the sample. This is known as Los Angeles
Abrasion value.
CONCLUSION: Comment on your results and state their compliance or otherwise with
standard values.
WK 5
EXPERIMENT NO.5: VISCOSITY TEST
THEORY: Viscosity of a liquid is the property that retards flow; so that
when a force is applied to a liquid, the higher the viscosity, the
slower will be the movement of the liquid. Viscosity of
bituminous binder is its most important characteristic. Hence,
viscosity measurements are useful not only in ensuring that
11
material with the desired consistency has been obtained but
also as a means of selecting binders for specific use.
APPARATUS: 1. Saybolt Furol Viscometer
2. Bath equipped with stirring and heating receiver
3. Oil tube thermometer
4. Timing device
5. Withdrawal tube or pipette
SAMPLE PREPARATION: Filter the material through a 100 mesh (150 micron) wire
strainer.
PROCEDURE: 1. Pour into container the quantity of material to be tested and
allow it to be draw.
2. Insert the cork stopper and pour material into the cup.
3. When the temperature of the bath and cup are steady or remain
constant, withdraw the thermometer and insert the tip of the
withdrawal tube at the point in the gallery.
4. Place the receiving flask in position. Snap the cork from its
position and at the same time start the timer.
5. Stop the timer when the bottom of the meniscus of the liquid
reaches the mark on the neck of the graduating receiving flask.
6. Record in seconds the time it takes for the 60ml of the oil to
flow by gravity from the completely filled cylinder as the
viscosity.
REFERENCE: AASHTO 72 – 68.
12
WEEK 6
EXPERIMENT NO.6: FLASH AND FIRE POINTS (CLEVEALAND OPEN UP)
THEORY: The flash and fire point test are indirect reflections of binder
volatility. The flash point is the more important of two, because
it indicates the maximum temperature to which the binder can
be safely heated.
APPARATUS: Cleveland open cup, Bunsen burner.
PROCEDURE: 1. Fill the cup with the material to be tested.
2. Light and adjust the test flame.
3. Place and test flame under the cup with the material to be
tested, thus the material is heated in the open cup.
4. At intervals a small flame is applied near its surface. The time
consumed in passing the flame across the cup shall be about 1
second.
5. Record as the flashpoint the temperature read on the
thermometer at which the material gives so much vapour that
will get temporarily or momentary ignite or flash on
application of a small pilot flame.
6. To determine the fire point, continue heating so that the sample
temperature increases at a rate of not less than 5oC or more than
6oC per minute.
7. Continue application of pilot flame until the vapour continues
to burn for a period of at least 5 seconds.
8. Record the temperature at which this occurs as the fire point.
REFERENCES: ASTM Standard 1958 part 4 D92
AASHTO T.48.
13
WEEK 7
EXPERIMENT NO.7: DUCTILITY TEST
THEORY: The ductility test is a measure of the internal cohesion of
bitumen. Bitumen possessing high ductility is normally
cementitious and adheres well to aggregate. The test is used as
a measure of the flexibility of the binder under slowly applied
load.
APPARATUS: Briquette brass mould, water bath, testing machine
PROCEDURE: 1. completely melt the bituminous material by heating it in an oil
bath maintained at minimum temperature needed to properly
liquefy the sample (for paving asphalt cements, the oil bath
shall be maintained at a temperature of 150 – 180oC.
2. Strain the melted sample through a No.50 (297 micron) sieve.
Stir thoroughly and pour into the mould. Assembly the mould
on a brass plate, and to prevent the material under test from
sticking, thorough amalgamate the surface of the plate and
interior surface of the sides of the mould.
3. Let the mould containing the material cool to room
temperature. Place it in the water bath maintained a temperature
of 25+0.5oC.
4. By means of a warm knife or spatula cut off the excess bitumen
to make the material just level full in the mould.
5. After the mould with briquette specimen had been in the water
for 1 ½ hours, remove the briquette from the plate, detach the
side pieces.
6. Transfer to the testing machine. Attach the rings at each side of
clips or pins to the hook in the testing machine and pull the two
clips apart at a uniform speed of 5cm/min.
14
7. Measure the distance in cm through which the clips have been
pulled to produce rupture. The test is carried out under water,
maintained at the test temperature in the ductilometer.
8. The average of three normal tests is the ductility of the sample.
9. Adjust the specific gravity of the bath (if necessary) by the
addition of sodium chloride so that the bituminous material
neither comes to the surface of the water, nor touches the
bottom of the bath at any time during the test.
REFERENCE: ASTM Standards 1958 part 4 D 113
Test Methods
ASTM 113, ASSHO T 51 –, J.P 32
15
WEEK 8
EXPERIMENT NO.8: SOFTENING POINT (RING AND BALL TEST)
THEORY: The specifications of many bituminous blinders for particular
purposes are often written without softening point requirement.
It is used to specify hard bitumens and it helps to characterize
its rate of setting. It may indicate the tendency to flow in
service in the case of thick films.
APPARATUS: A brass ring, a 9.5mm steel ball, ball guides, a glass beaker,
rings support, thermometer and stirrer
SAMPLE PREPARATION:
1. Heat the bitumen in a suitable vessel to 75 – 100oC above the
expected softening point and stir.
2. Heat the rings to approximately the same temperature.
3. Place them on a smooth metal plate covered with a coating of
glycerol and dextrin mixture to prevent the bituminous
material adhering to it overfill each ring with bitumen.
4. Allow to cool for 3mins, cut off the excess of bitumen with a
warmed knife, leaving it level.
5. Proceed with test within 4 hrs.
PROCEDURE: Materials having softening points 80oC or below
(a) Assembly of Apparatus: Fill in the glass beaker to a depth of 100mm with freshly boiled
distilled water (boiled to expel air). The water should be cooled
to 5oC.
1. Suspend the ring containing the sample in the water so that the
lower surface of the filled ring is 25mm above the upper
surface of the lower horizontal plate which is 12.5mm above
the bottom of the glass beaker.
2. Maintain the initial temperature of water for 15mins.
16
3. With forceps, place the ball in the centre of the upper surface of
the bitumen in the ring.
(b) Heating: Heat the water gently at about 5oC/mm, string. Avoid the
effects of draughts using shield if necessary. The rate of rise in
temperature shall be uniform; and shall not be average over the
period of the test. The maximum permissible variation in
temperature after the first three should not be average over the
period of the test. The maximum permissible variation in
temperature after the first three should not be more than 1oC.
Reject all tests in which the rate of rise exceeds these limits.
(c) Softening Point: Record as the softening point the temperature of the
thermometer at the instant the bituminous material touches the
horizontal plate.
Materials having softening points above 80oC: Use the same
procedure as described above except fill the bath with glycerin.
The starting temperature of the glycerin bath shall be 32oC.
Typical result 55oC, 56
oC, average 56½
oC, such bitumen would
be suitable for rolled asphalt, 50 – 75oC is required (BS 1418)
for DPC and tanking in mastic asphalt; 60 – 110oC are limit
for flooring (BS 1410), again mastic asphalt.
REFERENCES: ASTM Standard 1958, part 4, D-36
Bituminous materials in road construction
Road research laboratory.
17
WEEK 9
EXPERIMENT NO.9: STABILITY AND FLOW TEST
PRACTICAL SIGNIFICANE: Bitumen is extensively used for road construction, to
therefore aid in ensuring that bitumen has the desired quality
and that the optimum qualities of materials are used, optimum
bitumen content has therefore become a very important study
for determining the stability and resistance to plastic flow of the
bitumen.
APPARATUS: Marshall Apparatus which consists of the following part
1. Specimen and mould assembly with base plate and extension
collar
2. Specimen extractor
3. Compaction hammer
4. Specimen mould holder
5. Breaking head assembly
6. Loading jack
7. Compaction pedestal
8. One proving ring of 2700kg capacity complete with mounting
block and dial micrometer.
SAMPLE PREPARATION
1. Dry aggregates to constant weight at 105 to 110oC and separate
the aggregates by dry sieving into desired fraction.
2. Weight into separate pans, for each test specimen the amount of
each fraction required to produce a batch that will result in the
compacted specimen of 6.35cm in height and 10.16cm in
diameter.
18
3. Place the pan in hot plate and heat to a temperature of about
27oC above the mixing temperature.
4. Charge the mixing bowl with the heated aggregates and weigh
the required amount of bituminous material within the limit of
the mixing temperature. Mix the aggregate and bituminous
material rapidly until thoroughly coated.
PROCEDURE: 1. Clean the specimen mould assembly and the face of the
Compaction hammer and head immersed them either in boiling
water or on the hot plate to a temperature between 100oC and
150oC.
2. Place a piece of filter paper cut to the size in the bottom of the
mould before the mixture is introduced.
3. Place the entire batch into the mould; stir the mixture
vigorously with a heated spatula.
4. Replace the collar, and place the mould assembly on the
compaction pedestal and apply 50 blows with the compaction
hammers with the free fall of 45cm for a tyre pressure of
0.7MN/m2 and 75 blows for a tyre pressure of 1.4MN/m
2.
5. Remove the base plate and place the sample extractor on the
end of the specimen.
6. Place the assembly with the extension collar up to the testing
machine.
7. Apply pressure to the collar by means of the load transfer bar
and force the specimen into the extension collar and lift the
collar from the specimen.
8. Carefully transfer to a smooth, flat surface and allow it to stand
overnight at room temperature.
9. Weigh, measure and test the specimen.
10. Bring the specimens to the desired temperature by immersing
them in the water bath for 30 to 40 minutes. (The specified
temperature is 60oC for asphalt specimen and 38
oC for tar
specimen.
11. Remove the specimen from the water bath, dry and carefully
place it in lower testing head.
19
12. Place the upper head on the specimen. Then place the complete
assembly in position on the testing machine.
13. Place the dial micrometer in position over one of the guide rods
and adjust the flow meter reading to zero.
14. Hold the meter sleeve firmly against the upper segment of the
breaking head while the test load is being applied.
15. Apply the load on the specimen by means of a constant rate of
movement of the load jack or testing machine head at 5cm per
minute until the maximum is reached and the load decreases as
indicated by the dial.
16. Note and record the indicated flow value in terms of 0.25mm if
a micrometer dial is used to measure the flow.
17. The elapsed time for the test from the removal of the test
specimen from water bath to the maximum load determination
should not exceed 30 seconds.
18. The maximum load is the measure of stability.
RESULT: Report as findings
The report should include the following information for each
specimen test,
1. Height of the test specimen
2. Maximum load at failure
3. Flow value in multiple of 0.25m
4. Mixing temperature
5. compacting temperature
6. Test temperature
7.
TEST METHOD : ASTM D 1559 – 60
REFERENCES: 1. British Standard 3235 1984 – Test methods for bitumen
2. ASTM standard
20
WEEK 10
EXPERIMENT NO.7: HUBBARD FIELD TEST
AIM: To test the resistance to plastic flow of compressed bituminous
mixture.
APPARATUS: 1. Cylindrical moulds 5cm in diameter for preparing the
Specimen 5cm
2. Two plungers, one for the top end one for the bottom per
mould.
3. Pan and knife for heating and mixing bitumen and aggregate
4. Weighing balance
5. Compacting and loading unit of capacity 500kg and travel of
tension rod at a uniform rate of 6cm per minute.
PROCEDURE: 1. Take 90gm of sand, 10gm of cement and 5gm of bitumen.
2. Heat sand and cement on a container and add 5gm of hot
bitumen.
3. Mix thoroughly.
4. Place the bottom plunger into the mould. Put the mix on the
mould so that the height of the specimen is 2.5cm+0.125cm.
5. Put the top plunger over the mix and place in position in the
compacting machine and apply a load of 225kg. (This is
indicated by 75 divisions of the strain gauge).
6. Take out the mould and place it in cold water for one hour and
take out the sample.
TESTING OF SPECIMEN
1. Place the specimen in the test mould assembly over the test ring
with plunger on the top.
8. Apply the compressive load at a constant rate of deformation of
6.0cm per minute.
21
RESULT: Report the failure value of the strain and determine the
failure load.
CONCLUSION: Comment on your result and state their compliance or
otherwise with stander value.
22
WEEK 11
EXPERIMENT NO.11: DESIGN TRIAL MIX OF PLASTIC CONCRETE
THEORY: The most popular method of mix design is eh Marshall method.
The Hveem stabilometer is less used. Other methods are the
Hubbard field and Smith triavial.
Marshall method uses standard test specimens of 6.35cm
height and 10.16cm diameter. The principal features of the
method are a density-void analysis and stability flow test of the
compacted specimen.
PROCEDURE: The test specimens are prepared with varying asphaltic cement
content with ½% increments such that at least two values are
above and two below the optimum. Usually 6 values of
asphaltic cement content are selected and for each three
specimens are needed. The specimens are prepared by heating
the aggregates and buder and mixing them both top and bottom
by the hammer. The procedure is adequate for highway
pavements designed for a type pressure of 0.7MN/m2. For
airfield pavements and heavily trafficked highway pavements
designed for a tyre pressure of 1.4MN/m2, 75 blows are given
on each face. The Marshall testing machine is an electrically
powered testing device design to apply loads at a constant rate
of strain of 5cm per minute and equipped with a calibrated
proving ring to measure the load. The machine measures both
stability and flow that developed at failure. The measured
stability values are next corrected to those which would have
been obtained if the specimen has been exactly 63.5mm high.
This is done by multiply correlation value.
DENSITY VOID ANALYSIS: The theoretical specific gravity (density) GM for void less
bituminous paving mixtures is determined by
GM = 100
W1 + W2 + W3 ……….Wn
G1 G2 G3 Gn
Where
W1 = the percentage by weight of bitumen
23
G1 = the specific gravity of bitumen
W2, W3 =…Wn = percentages by weight of different aggregate
fractions.
G2………. Gn = specific gravities of the respective aggregate
fraction.
The procedure for determining d, the bulk specific gravity of a
compacted specimen is given in AASHTO T – 166 as
d = A
B – C
Where
A = weight of the dry specimen in air in grams
B = weight of saturated surface dry specimen in air, in grams.
C = weight of saturated specimen in water, in grams.
If the specimen has an open and porous surface, it must be
covered with a paraffin coating before being in the water. The
formula for determining d, the bulk specific gravity of a
compacted asphaltic mixture when the specimen is coated with
paraffin is as thus follows:
d = A
D – E – D – A
F
Where
A = weight of the dry specimen in air, in grams
D = weight of the specimen plus paraffin coating in air, in
grams.
E = weight of the specimen plus paraffin coating in water, in
grams.
F = bulk specific gravity of the paraffin
The percentage of voids (V.T.M) in an actual paving mixture is
determined by
V.T.M = (Gm – d) x 100
Gm
V.T.M = voids in the total mixture is d in the specimen %.
Again, for each specimen, calculate the percentage of voids in
the compacted mineral aggregate frame work which is filled
with the binder. This involves first determining the amount of
24
voids in the aggregate framework (V.M.A) and then calculating
the percentage filled with binder material.
The V.M.A is obtained by subtracting the volume occupied by
the aggregate in the compacted specimen from the bulk volume
of the compacted specimen, i.e. the volume of voids which in
theory is available for filling with binder. Thus,
V.M.A = V - VE – VF VMF
Where W - Wc - Wf - Wmf
D Gc Gf Gmf
V.M.A = voids in the mineral aggregate framework cm3
V = volume of specimen, cm3
Vc = Vf Vmf = volume of coarse, fine and mineral filler
fraction, respectively, of the aggregates in the specimen, cm3.
W = weight of the specimen, gm
Wc, Wf and Wmf = weight of coarse, fine and mineral filler
fractions respectively of the aggregates in the specimen, gm.
Gc, Gf and Gmf = Apparent specific gravities of coarse, fine and
mineral fractions respectively, of the aggregate in the specimen.
The voids in the mineral aggregate framework are often
expressed as a percentage of the total volume of the specimen.
Thus
% V.M.A = V.M.A x 100
V
In order to obtain individual binder content for stability, flow,
density and voids, separate graphical plots are prepared for the
following;
(a) Binder content versus marshall stability
(b) Binder content versus marshal flow
(c) Binder content versus percentage of voids in the total
mix
(d) Binder content versus percentage of voids in the mineral
aggregate framework filled with binder.
(e) Binder content versus unit weight
For illustrate purposes the data in Table 11.1 are plotted in fig
11.1 and t eh points joined with smooth curves.
25
Table 11.1 Typical Marshall Test Data
Binder content
% Stability KN Flow Units Percentage of air
voids in the total
mixture
Percentage of
filled voids in
the aggregate
framework
Unit weight
kg/m3
3 4.89 8.9 12.5 34 2169
4 7.06 9.4 7.2 65 2207
5 8.06 11.8 3.9 84 2255
6 7.52 14.6 2.4 91 2227
7 6.49 19.2 1.9 93 2190
8000
7000
6000
5000
2 4 6 8
.
. .
.
Sta
bili
ty N
5
2 4 6 8
4
3
2
1
0
. .
. . .
Mars
hall
flow
m
m
20
10
0
2 4 5 7
. .
.
.
Void
s in
tota
l m
ix %
100
50
20
2 5 8
.
.
.
.
Aggre
gate
void
s file
d
with bin
der
%
2300
2250
2200
2 5 7
Unit w
t kg/m
3
. . .
.
26
The next stage involves the determination of optimum binder
content. From these curves, the individual binder content is
determine d for the following conditions
(a) max stability
(b) max unit wt
(c) median limit or percent air void
The numerical average binder content from these three is taken
as the optimum binder contended is used in design, provided it
gives a mixture that satisfies the established criteria. The
marshall criteria normally adopted for design are given in Table
11.2.
For the illustrative data, the optimum binder content is found
as:
Property Unit weight Stability V.T.M
Binder content % 5.0 5.0 4.9
The optimum binder content is taken as the average of these
three binder.
i.e. 5 + 5 + 49 = 4.97
3
4.97% is the optimum binder content for the mix.
Table 11.2 Design criteria for Marshall method of design.
Traffic category Heavy (Tyre pressure
1.4MN/m2)
Medium (Tyre pressure
0.75MN/m2)
Pavement use Airport pavement and
heavily trafficked
highways
Highways with low
traffic
No of blows at each
end of specimen 75 50
Stability 650 200 Flow 10.25mm 16max 20max % air voids 3 – 5 3 – 5 % voids in
aggregate filed with
bitumen
75 – 82 72 – 85
27
WEEK 12
EXPERIMENT NO.12: DESIGN OF TRIAL MIX OF PLASTIC CONCRETE
CLASS ACTIVITY: A specimen of asphaltic concrete has a height of 6.20cm and a
diameter of 10.16cm, the weight of the compacted specimen
(uncoated) in air is 1174.4gms and in water, the weight is
668.4gms. When coated with paraffin, its weight in air is
1220.9gms and its weight when immersed in water is
664.4gms. The specific gravity of paraffin is 0.90. The analysis
of the specimen yielded the following:
S/No Material Specific
gravity
Mix composition
(% by weight of
total mix)
Aggregate
composition (%
by weight of total
aggregates)
1. Asphaltic cement 1.02 6.0
2 Coarse aggregate 2.58 52.0 55.3
3 Fine aggregates 2.72 34.6 36.8
4 Mineral filler 2.70 7.4 7.9
100.0 100.0
Calculate
(i) Bulk density of specimen by uncoated specimen
procedure and immersion test.
(ii) Bulk density of specimen from specimen dimensions.
(iii) Bulk density of specimen by paraffin coated sample
procedure.
(iv) Average specific gravity of the aggregates
(v) Maximum theoretical density
(vi) Bulk density as percent of maximum density
(vii) Percent voids in compacted mix
(viii) Percent volume occupied by asphaltic cement, coarse
aggregate, fine aggregates, mineral filler.
(ix) Percentage volume of voids in mineral aggregate
(VMA).
(x) Percent aggregate voids filled with asphalt.
28
Solution:
(i) Bulk density of specimen by uncoated specimen
immersed in water
W
W - Wsw
1174.74
1174.4 – 668.4
1174.4
506.3 = 2.320gm/cc
(ii) Bulk density from dimensions of specimen
= 1174.4
π x 10.16 x 10.16 x 6.20
4
= 2.337
(iii) Bulk density from paraffin coated specimen
WSA
WSA1
– WSW1
– ( WSA1
–WSA)
GP
= 1174.4
1220.9 – 664.4 – (1220.9 – 1174.4)
0.9
= 1174.4/505.2
= 2.325
(iv) Average specific gravity
Gag = Wag
Wca + Wfa + Wmf
Gca Gfa Gmf
= 100
55.3 + 36.8 + 7.9
2.58 2.72 2.70
(v) Maximum Theoretical density
W
29
Wac + Wag
Gac Gag
= 1174.4
0.06 x 1174.4 + 0.94 x 1174.4
1.02 2.64
= 2.41gm/cc
(vi) Bulk density as percent of max theoretical density
= 2.32 x 100 = 96.3%
2.41
(vii) Percentage voids in compacted mix
% V = V – Vac - Vca - Vfa - Vfm x 100
V
= 1174.4 - 1174.4 x 0.06 - 1174.4 x 0.052
2.32 1.02 2.58
= 1174.4 x 0.346 - 1174.4 x 0.074
2.72 2.70
_____________________________ x 100
1174.4
2.32
= 3.7%
This is also given by
100 - Ɣm x 100
Ɣm1
100 – 2.32 x 100
2.41
100 – 96.3 = 3.7%
(viii) Percent volume occupied by constituents
% Vac = 6.00 x 2.32 = 13.7%
1.02
% Vca = 52.0 x 2.32 x 100 = 46.8%
2.58
% Vfa = 34.6 x 2.32 = 29.5%
2.72
% Vmf = 7.4 x 2.32 = 6.3%
2.70
% Vmf = 94.0 x 2.32 = 82.6%
2.64
30
(ix) Percent volume of voids in mineral aggregate
(VMA)
= 100 - % weight of aggregate x W
Gag x V
100 – 0.94 x 1174.4 x 2.32
2.64 x 1174.4
= 100 – 82.6
= 17.4%
(x) Percent of aggregate voids filled with Asphaltic
concrete
= Percent of asphaltic cement in mix x 100
Percent of voids in mineral aggregate
= 13.7 x 100 = 78.7%
17.4
31
WEEK 13
EXPERIMENT NO.12: DESIGN OF TRIAL MIX OF PLASTIC CONCRETE
CLASS ACTIVITY: A specimen of asphaltic concrete has a height of 6.20cm and a
diameter of 10.16cm, the weight of the compacted specimen
(uncoated) in air is 1174.4gms and in water, the weight is
668.4gms. When coated with paraffin, its weight in air is
1220.9gms and its weight when immersed in water is
664.4gms. The specific gravity of paraffin is 0.90. The analysis
of the specimen yielded the following:
S/No Material Specific
gravity
Mix composition
(% by weight of
total mix)
Aggregate
composition (%
by weight of total
aggregates)
1. Asphaltic cement 1.02 6.0
2 Coarse aggregate 2.58 52.0 55.3
3 Fine aggregates 2.72 34.6 36.8
4 Mineral filler 2.70 7.4 7.9
100.0 100.0
Calculate
(xi) Bulk density of specimen by uncoated specimen
procedure and immersion test.
(xii) Bulk density of specimen from specimen dimensions.
(xiii) Bulk density of specimen by paraffin coated sample
procedure.
(xiv) Average specific gravity of the aggregates
(xv) Maximum theoretical density
(xvi) Bulk density as percent of maximum density
(xvii) Percent voids in compacted mix
(xviii) Percent volume occupied by asphaltic cement, coarse
aggregate, fine aggregates, mineral filler.
(xix) Percentage volume of voids in mineral aggregate
(VMA).
(xx) Percent aggregate voids filled with asphalt.
32
Solution:
(i) Bulk density of specimen by uncoated specimen
immersed in water
W
W - Wsw
1174.74
1174.4 – 668.4
1174.4
506.3 = 2.320gm/cc
(ii) Bulk density from dimensions of specimen
= 1174.4
π x 10.16 x 10.16 x 6.20
4
= 2.337
(iii) Bulk density from paraffin coated specimen
WSA
WSA1
– WSW1
– ( WSA1
–WSA)
GP
= 1174.4
1220.9 – 664.4 – (1220.9 – 1174.4)
0.9
= 1174.4/505.2
= 2.325
(iv) Average specific gravity
Gag = Wag
Wca + Wfa + Wmf
Gca Gfa Gmf
= 100
55.3 + 36.8 + 7.9
2.58 2.72 2.70
(v) Maximum Theoretical density
W
33
Wac + Wag
Gac Gag
= 1174.4
0.06 x 1174.4 + 0.94 x 1174.4
1.02 2.64
= 2.41gm/cc
(vi) Bulk density as percent of max theoretical density
= 2.32 x 100 = 96.3%
2.41
(vii) Percentage voids in compacted mix
% V = V – Vac - Vca - Vfa - Vfm x 100
V
= 1174.4 - 1174.4 x 0.06 - 1174.4 x 0.052
2.32 1.02 2.58
= 1174.4 x 0.346 - 1174.4 x 0.074
2.72 2.70
_____________________________ x 100
1174.4
2.32
= 3.7%
This is also given by
100 - Ɣm x 100
Ɣm1
100 – 2.32 x 100
2.41
100 – 96.3 = 3.7%
(viii) Percent volume occupied by constituents
% Vac = 6.00 x 2.32 = 13.7%
1.02
% Vca = 52.0 x 2.32 x 100 = 46.8%
2.58
% Vfa = 34.6 x 2.32 = 29.5%
2.72
% Vmf = 7.4 x 2.32 = 6.3%
2.70
% Vmf = 94.0 x 2.32 = 82.6%
2.64
34
(ix) Percent volume of voids in mineral aggregate
(VMA)
= 100 - % weight of aggregate x W
Gag x V
100 – 0.94 x 1174.4 x 2.32
2.64 x 1174.4
= 100 – 82.6
= 17.4%
(x) Percent of aggregate voids filled with Asphaltic
concrete
= Percent of asphaltic cement in mix x 100
Percent of voids in mineral aggregate
= 13.7 x 100 = 78.7%
17.4
35
WEEK 14 TO 15
EXPERIMENT NO.14: STUDENTS TO BE TAKEN TO ROAD
CONSTRUCTION SITE
AIM: To identify different types of construction equipment and to see
the organization of site works.
OBJECTIVE: Know the uses of the equipment and to be aware of the
organizations of a site, together with the responsibility of the
staff.
REPORT: Students will be expected to write reports on different types of
construction equipment including diagrams and sketches seen
on site.
RESULT: a comprehensive report to be written, not less than 1000 words
and to be submitted 2 weeks after site visitation.
CONCLUSION: To be assessed by the lecturer.
