HIGHWAY AND TRANSPORTATION ENGINEERING

(FACULTY OF ENGINEERING)

PAVEMENT MATERIALS

Marshall Mix Design (Mini Project)

 TABLE OF CONTENTS

1.0 PROBLEM STATEMENT

2.0 OBJECTIVE
3.0 METHODOLOGY
4.0 PREPERATION OF THE SAMPLE & CALCULATION
4.1 AGGREGATE GRADATION
4.2 ASPHALT CONTENT
4.3 CELLULOSE FIBER
6.0 ASPHALT
6.1 PENETRATION TEST
6.2 SOFTENING POINT TEST
6.3 FLASH AND FIRE POINT TEST
6.4 VISCOSITY TEST
7.0 MARSHALL SPECIMENS
8.0 TESTING MARSHALL SPECIMENS
8.1 RICE SPECIFIC GRAVITY (TMD)
8.2 DENSITY AND VOID ANALYSIS
8.3 RESILIENT MODULUS TEST
8.4 MARSHALL STABILITY AND FLOW TEST
9.0 ANALYSIS
9.1 THEORITICAL MAXIMUM SPECIFIC GRAVITY
9.2 DENSITY AND VOID ANALYSIS
9.2.1 BULK SPECIFIC GRAVITY
9.2.2 VOID IN TOTAL MIX (VTM)
9.2.3 VOIDS IN MINERAL AGGREGATES (VMA)
9.2.4 VOIDS FILLED WITH ASPHALT (VFA)
9.3 FLOW & STABILITY ANALYSIS
9.4 RESILIENT MODULUS ANALYSIS
9.5 DETERMINATION OF OPTIMUM ASPHALT CONTENT
10.0 CONCLUSION
11.0 RECOMMENDATION

1
1.0 PROBLEM STATEMENT

A turnkey road project was granted to your firm. You are responsible for carrying out the
construction of wearing course which is recommended to be Stone Mastic Asphalt. The
design consultants have come up the following SMA (14) requirement which will be
formulated at the firms Asphalt laboratory using the Marshall Procedure.

Road Project
SMA Mix Requirement:
Binder = Pen 60/70
Aggregate = Granite
SMA Specification
Minimum Stability = 8kN
Minimum Resilient Modulus = 3,000MPa
Minimum VMA = 16.5%
VTM = 3-5 %
Flow = 2-4 mm
Cellulose Fiber = 0.3% by weight of Aggregate

2.0 OBJECTIVE

The objectives of this mix design are as follows:

i. To determine the optimum asphalt content (OAC) for Stone Mastic Asphalt.
ii. To check the performance of mix design obtained are complied with the JKR
requirement, JKR/SPJ/2008-S4.

2
3.0 METHODOLOGY

Binder Testing
•Sieving •Aggregates +
•Grading Cellulose Fiber
•Weight 10 •Pen 60/70 •Binder •Rice method
Samples (1100 •Moulding
•Heat to1700C •Bulk specific
grams each) •Compacting gravity
•Drying •Coolling •Resilient modulus
•Heating 1900C
•Stability and flow

Aggregate Mixing

Figure 1: Methodology of the project

4.0 PREPARATION OF THE SAMPLE & CALCULATION

4.1 AGGREGATE GRADATION

Desired grading was worked out and the results are as shown in the Table 1. When these
results were plotted, a smooth curve is obtained which is within the specified grading limits
for asphaltic concrete.

The weight for each size sieve was determined as follows:

Total weight of aggregate used for each specimen is 1100g
Weight of aggregate for each sieve size = desired percentage retained (%) × total weight

3
Figure 2: Sieve machine (left) and Aggregate is sieved through the specified sieve
size(right)

Figure 3: Aggregate retained on individual sieve is weighed

4
 SMA14
ASTM SIEVE SPEC DESIRED
% % Wt Retained
Sieve size (mm) % Passing Passing Retained (g)
19.00 100 100 0 0
12.50 100 100 0 0
9.50 72 83 77.5 22.5 247.5
4.75 25 38 31.5 46 506
2.36 16 24 20 11.5 126.5
0.60 12 16 14 6 66
0.30 12 15 13.5 0.5 5.5
0.075 8 10 9 4.5 49.5
Pan 0 9 99
TOTAL 100 1100
0.3% Cellulose
Fiber 0.3 3.3
WT PER SAMPLE 1103.3
Table 1: Percentage Passing of Gradation

Gradation Chart
120

100
Percentage Passing, %

80

60

40

20

0
0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00
Sieve size, mm

LL UL Desired

Figure 4: Graph of combined gradation

Percentage of Coarse Percentage of Fine Percentage of Filler

Aggregate Aggregate
68.5% 22.5% 9%
Table 2: Percentage of coarse, fine aggregate and filler

5
Coarse Aggregate
(Weight of sample of 19 mm sieve size + weight of sample of 12.5 mm of sieve size
+ weight of sample of 9.5 mm sieve size + weight of sample of 4.75 mm sieve size)
Percentage = x
Total Weight of Aggregate

100%
0+ 0+247.5+506.0
= x 100%
1100

= 68.5%
68.5% is acceptable because it is above the JKR minimum requirement which is 65%

Fine Aggregate
(Weight of sample of 2.36 mm sieve size+ weight of sample of 0.600 mm sieve size
+ weight of sample of 0.300 mm of sieve size+ weight of sample of 0.075 mm sieve size)
Percentage = x
Total Weight of Aggregate

100%
126.5+ 66+5.5+49.5
= x 100%
1100

= 22.5%
Filler
Weight of Sample of Filler Sieve
Percentage = x 100%
Total Weight of Aggregate
99
= 1100 x 100%

= 9%
9% is acceptable because it is above JKR minimum requirement which is 8%

4.2 ASPHALT CONTENT

Calculation of asphalt content: Total weight of aggregate is 1100g

Asphalt required (g)
𝑿
Percent of asphalt = 𝑿 + 𝒘𝒆𝒊𝒈𝒉𝒕 𝒐𝒇 𝒂𝒈𝒈𝒓𝒆𝒈𝒂𝒕𝒆+𝑪𝒆𝒍𝒍𝒖𝒍𝒐𝒔𝒆

For 4.5% asphalt binder:

4.5 X
= X+1103.3
100

95.5X = 4964.85
X = 51.98g

6
For 5.0% asphalt binder:
5.0 X
= X+1103.3
100

95X = 5516.5
X = 58.07g
For 5.5% asphalt binder:
5.5 X
=
100 X+1103.3

94.5X = 6068.15
X = 64.21g
For 6.0% asphalt binder:
6.0 X
= X+1103.3
100

94X = 6619.8
X = 70.42g
For 6.5% asphalt binder:
6.5 X
=
100 X+1103.3

93.5X = 7171.45
X = 76.7g

% AC Weight of AC (g)
4.50 51.99
5.00 58.07
5.50 64.21
6.00 70.42
6.50 76.70

Table 3: Summary weight of asphalt required

The specific gravity of asphalt at 25 °C = 1.03.

7
4.3 CELLULOSE FIBER

Calculation of Cellulose Fiber:

Cellulose Fiber is adding 0.3% by weight of the combined aggregate:
CIPB = 0.003 x 1100 = 3.3g

Figure 5: Cellulose Fiber

8
6.0 ASPHALT

The bituminous binder used for this experiment was grade PG76 and it comply with
AASHTO Standard M320-02. The performance shall be achieved by incorporating an
appropriate quantity of polymer additives to conventional bitumen, which shall be penetration
grade 80/100 conforming to M.S.124.

Properties Requirement
Penetration Test 80mm – 100mm
Softening point 40oC – 60oC
Flash Point 260oC minimum
Specific Gravity 1.01 – 1.06
Table 5: Requirement for Various Asphalt tests

TESTING MATERIAL FOR ASPHALT

6.1 PENETRATION TEST (ASTM D5)

The objective of this test is to determine the penetration of the asphalt at certain force and to
determine the hardness or softness of the asphalt at room temperature (25°C). If the results
give a higher value of penetration its shows a softer consistency.

Testing procedure:

1. Place the sample in a container of 100g. Condition the sample at room temperature
25°C.
2. Clean the penetration needle with a solvent and dry it with clean cloth.
3. Place the sample under the needle.
4. Adjust the needle position slowly until the tips makes contact with of the surface of the
sample.
5. Release the needle holder in 5 seconds and get the end reading.
6. Repeat at least three times at different points on the surface not less than 10mm from
the side and 10mm apart.
7. Take the average value for as the result.

9
Results:

Number of Penetration (mm) Average

Penetration Penetration (mm)
1 64
2 60
3 60 61
4 60
5 61
Table 6: Result for penetration test

Figure 6: Penetration test Apparatus

10
6.2 SOFTENING POINT TEST (RING & BALL METHOD) (ASTM D36)

To determine the softening point or melting point properties of the bitumen. Bitumen with
higher softening point are melted at higher temperature which is better in avoid the rutting.

Testing Procedure:

1. Fill the hot asphalt at the ring sufficiently free from air bubble and let it cooled at room
temperature for 30 minutes.
2. Condition the sample to 5°C for 45 minutes
3. Assemble the apparatus with the rings, thermometer and ball in positions
4. Place the sample in the water bath at level not less than 102mm and not more than
180mm from bottom of the bath
5. Apply the heat to the water bath and stir it so that the temperature will rise uniformly of
5°C per minute
6. Take the temperature when the ball touches the bottom plate

Results:

Test 1 2 Average
Softening Point (°C) 51.1 51.3 51.2

Table 7: Softening point test

11
Figure 7: Preparation of the sample (left and right)

Figure 8: Apparatus for softening point test

12
6.3 FLASH AND FIRE POINT TEST (ASTM D92)

This experiment is to obtain the temperature level of the asphalt materials for flash and fire
point. This is to determine the optimum temperature level.

Testing procedure:

1. Heating asphalt above the softening point to able it to fill the test cup.
2. Fix the thermometer inside the sample. (don’t touch the cup bottom)
3. Start the test heater to heat in a rate of (5-6)⁰C/min.
4. Before the expected Flash point by about (28⁰C) start to close the flame from the
samples surface each (1⁰C) until (104⁰C).
5. Continue with step (4) after (104⁰C) but in intervals of each (3⁰C).
6. Compute the flash and fire points when they happened
Results:

Flash Point (°C) 253

Fire Point (°C) 258

Table 8: Result of Flash & Fire point test

Figure 9: Apparatus for Flash and fire test

13
6.4 VISCOSITY

Viscosity can simply be defined as resistance to flow of a fluid. Viscosity grading of asphalt
cements is based on viscosity measurement at 60°C. This temperature was selected because it
approximates the average pavement surface temperature during hot weather. Viscosity also
measured at 170°C, where this temperature approximates the mixing temperature.

Brookfield rotational viscometer is used accordance to ASTM D4402 to determine the

viscosity of the asphalt cement at different temperatures. About 10ml of preheated asphalt
cement was poured into the thermocel. The appropriate spindle and RPM are selected to carry
out the test. The results are reported in centipoise.

Results:

Temperature Time(mins) cP(Viscosity) cP Average

5 592.8

4 587.3

3 583.8

135 2 581.9 584.15

1 579.8

0 579.3

5 149.8

4 151.7

165 3 150.9 150.95

2 150.3

1 152.6

0 150.4

Table 9: Viscosity Results

14
Figure 10: Equipment for viscosity test

Figure 11: Graph for viscosity

15
Result of Viscosity:

Compaction Range (°C) 153.5 – 157.5

Mixing Range (°C) 162- 165

Table 10

16
7.0 MARSHALL SPECIMENS

Objective:
To prepare standard specimens of asphaltic concrete for determination of stability and flow in
the Marshall apparatus and to determine density, percentage air voids and percent of
aggregate voids filled with binder.

Testing Procedure:
i. The aggregate, graded according to the ASTM or BS standard are oven-dried at 180◦C-
200◦C and sufficient amount is weight (about 1100 g) for sample preparation that may
give a height of 63.5 mm when compacted in the mould.
ii. The required quantity of asphalt is weight out and heated to a temperature of about
165◦C-170◦C
iii. The aggregate is heated in the oven to a temperature not higher than 28 ◦C above the
binder temperature

Figure 12: Aggregate heated in the oven

17
 Figure 13: Heating all the apparatuses to the sample temperature in the oven

iv. Coarse aggregate and cellulose fiber are mixed in the bowl and the binder (amount
based on calculation) poured in the middle of aggregate. Mixing carried out until
all the coarse aggregate and Cellulose fiber are coated. Filler poured into the mixture
after coarse aggregate and cellulose fiber are coated. The mixing temperature shall be
within the limit set for the mixing temperature (162°C - 165°C: Result from viscosity
test). The thoroughly cleaned mould is heated on a hot plated or in an oven to a
temperature between 140◦C and 170◦C. The mould is 101.6 mm diameter by 76.2 mm
high and provided with a base plate and extension collar.

v. A piece of filter paper is fitted in the bottom of the mould and the whole mix poured
in three layers. The mix in the center, leaving a slightly rounded surface. Put another
filter paper in the top of the mould.

vi. The mould is placed on the Marshall Compaction pedestal and compacted with 50
blows to each side with compaction temperature (154°C - 158°C: Result from viscosity
test). Immediately after compaction, remove the compacted mould to cool it down until
warm.

18
 Figure 14: Marshall Compaction Machine

vii. The specimens are then carefully removed from the mould, transferred to a
smooth, flat surface and allowed to cool to room temperature.

Figure 15: 15 Samples of SMA

19
8.0 TESTING MARSHALL SPECIMENS

8.1 RICE SPECIFIC GRAVITY/ THEORETICAL MAXIMUM DENSITY (TMD)

Scope of work for TMD (AASHTO T 209)

This test determines the theoretical maximum specific gravity and density of loose SMA
mixtures at 77°F (25°C). (AASHTO T 209: Theoretical Maximum Specific Gravity and
Density of Bituminous Paving Mixtures)

8.2 DENSITY AND VOID ANALYSIS (ASTM D2726)

i. Cool the specimens to 77±9°F(25±5°C) and weigh each specimen. Record this mass
as specimen in air.
ii. Immerse each specimen in water at 77±1.8°F(25±1°C) suspended beneath a balance
for a period of 3 to 3½minutes. Record this mass as specimen in water.
iii. Remove the specimen from the water and surface dry by blotting with a damp towel.
Weigh the mass as quickly as possible and record as surface-dry specimen in air.

8.3 RESILIENT MODULUS TEST (ASTM D4123)

Objective:
The Resilient Modulus Test is carried out to measure the stiffness modulus of asphalt mixes.
It is carried out using the Material Testing apparatus (MATTA).

Testing Procedure:
i. Specimen are to be kept in the MATTA machine at a temperature of 25°C for at least
two hours and the pressure adjusted to 750 kPa. A direct compressive load is to be
applied through a 12mm wide loading strip along the vertical diameter of the
specimens. The linear variable differential transducers (LVDTs) are used to monitor the
resultant indirect tensile stress and strain along the horizontal diameter.

ii. Prior the actual test, an initial conditioning of five load pulses with a three second
interval between pulses, is applied in the subsequent test period to generate sufficient
horizontal deformation without damaging the specimens. These pulses also serve to
bed the loading strips on to the specimens.

20
 Figure 16: MATTA Machine and Placing sample in the machine

iii. The rise and the rest times in the between the initial application and the peak value of
the load is arbitrarily specified at 100 milliseconds. Observe that the rise time gives a
load-time relationship with a clearly defined peak at 20°C for all the specimens tested.
The test conditions as described above are essentially maintained throughout the test, as
the elastic stiffness depends on these conditions.

iv. For each specimen, the test is repeated after rotating the specimen through
approximately 90°. Provided the difference is about 10% or less, the mean of the two
test results is taken as the elastic stiffness of the specimen.

Figure 17: Resilient Modulus Test

21
Calculation:
Resilient Modulus = Stress / Strain = [Rv (R + 0.27)] / YHT

8.4 MARSHALL STABILITY AND FLOW TEST (ASTM D1559)

Introduction:
This method covers the measurement of resistance to plastic flow of cylindrical specimens of
asphalt mixtures loaded on the lateral surface by means of the Marshall apparatus. This
method is for use with mixtures containing asphalt cement, asphalt cutback, and aggregate up
to 25.4 mm maximum size. At least 3 test specimens should be used and the individual results
averaged. Repeatability shall be as outlined in ASTM D1559, Standard Test Method for
Resistance to Plastic Flow of Bituminous Mixtures Using Marshall Apparatus.

Apparatus Used:
i. Breaking Head
ii. Loading Jack
iii. Ring Dynamometer Assembly or Electronic Equivalent
iv. Flow meter
v. Water Bath
vi. Air Bath

Testing Procedure:

i. The prepared specimens are immersed in a water bath 30 minutes. Maintain the bath or
oven temperature at 60 ± 1oC for asphalt cement specimens.

ii. The testing head temperature shall be maintained between 21.1oC to 37.8oC.

iii. Remove the specimen from the water bath, oven or air bath and place in the lower
segment at the breaking head. Place the upper segment of the breaking head on the
specimen and place the complete assembly in position on the testing machine. Place the
flow meter, where used, in position over one of the guide rods and adjust the flow meter
to zero while holding the sleeve firmly against the upper segment of the breaking head.
Hold the flow meter sleeve firmly against the upper segment of the breaking head while
the test load is being applied.

iv. Apply the load to the specimen by means of the constant rate of movement of the
load jack or testing machine head of 50.8 mm/minute until the maximum load is
reached and the load decreases as indicated by the dial

22
 v. Record the maximum load noted on the testing machine or converted from the
maximum micrometer dial reading.

vi. Release the flow meter sleeve or note the micrometer dial reading, where used, the
instant the maximum load begins to decrease. Note and record the indicated flow value
or equivalent units in mm if a micrometer dial is used to measure the flow.

vii. The elapsed time for the test from removal of the test specimen from the water bath
to the maximum load determinations shall not exceed 30 seconds

Figure 18: Stability and Flow Test

Calculation:
For specimens other than 63.5mm in thickness, the load corrected by using the proper
multiplying factor below:

Volume of Specimen
Thickness of Specimen (mm) Correlation Ratio
(cm3)
200 to 213 25.40 5.56
214 to 225 27.00 5.00
225 to 237 28.60 4.55
238 to 250 30.20 4.17

23
251 to 264 31.80 3.85
265 to 276 33.30 3.57
277 to 289 34.90 3.33
290 to 301 36.50 3.03
302 to 316 38.10 2.78
317 to 328 39.70 2.50
329 to 340 41.30 2.27
341 to 353 42.90 2.08
354 to 367 44.40 1.92
368 to 379 46.00 1.79
380 to 392 47.60 1.67
393 to 405 49.20 1.56
406 to 420 50.80 1.47
421 to 431 52.40 1.39
432 to 443 54.00 1.32
444 to 456 55.60 1.25
457 to 470 57.20 1.19
471 to 482 58.70 1.14
483 to 495 60.30 1.09
496 to 508 61.90 1.04
509 to 522 63.50 1.00
523 to 535 64.00 0.96
536 to 546 65.10 0.93
547 to 559 66.70 0.89
560 to 573 68.30 0.86
574 to 585 71.40 0.83
586 to 598 73.00 0.81
599 to 610 74.60 0.78
611 to 625 76.20 0.76

Table 11: Stability correlation ratios

24
9.0 ANALYSIS
9.1 TMD
Theoretical maximum specific gravity (TMD, Gmm):
The ratio of the mass of a given volume of void-less (Va = 0) HMA at a stated
temperature (usually 25 °C) to a mass of an equal volume of gas-free distilled water at
the same temperature. It is also called Rice Specific Gravity (after James Rice who
developed the test procedure). Multiplying Gmm by the unit weight of water gives
Theoretical Maximum Density (TMD).

The standard TMD test is:

AASHTO T 209 and ASTM D 2041: Theoretical Maximum Specific Gravity and
Density of Bituminous Paving Mixtures.
Gmm = Wair / Wwater – Wair

Since, there is not test results, then we find value Gmm by using equation

Gmm=(100 /(%agg/SGagg)+(%binder/SGb))

At, 4.5% ,Gmm=(100/(95.5%/2.6)+(4.5%/1.03))=2.433

(Full result in table 12)

9.2 DENSITY AND VOID ANALYSIS

Introduction
A major concern of the Stone Mastic Asphalt (SMA) industry is the proper measurement of
the bulk specific gravity (Gmb) for compacted SMA samples. This issue has become a bigger
problem with the increased use of coarse gradations. Gmb measurements are the basis for
volumetric calculations used during SMA Mix Design, field control, and construction
acceptance. During mix design, volumetric properties such as air voids, voids in mineral
aggregates, voids filled with asphalt, and percent maximum density at a certain number of
gyrations are used to evaluate the acceptability of mixes.

For many years, the measurement of Gmb has been accomplished by the water is placement
concept, using saturated-surface dry (SSD) samples. This consists of first weighing a dry
sample in air, then obtaining a submerged mass after the sample has been placed in a water
bath for a specified time interval. Upon removal from the water bath, the SSD mass is
determined after patting the sample dry using a damp towel.

25
9.2.1 BULK DENSITY

Bulk specific gravity (Gmb):

The ratio of the mass in air of a unit volume of a permeable material (including both
permeable and impermeable voids normal to the material) at a stated temperature to
the mass in air (of equal density) of an equal volume of gas-free distilled water at a
stated temperature. This value is used to determine weight per unit volume of the
compacted mixture. It is very important to measure Gmb as accurately as possible.
Since it is used to convert weight measurements to volumes, any small errors in Gmb
will be reflected in significant volume errors, which may go undetected.

The standard bulk specific gravity test is:

AASHTO T 166: Bulk Specific Gravity of Compacted Bituminous Mixtures Using
Saturated Surface-Dry Specimens.

Where,
Gmb = Bulk specific gravity of the mix
ρw = density of water ( = 1g/mm3)

Gmb = WD / (WSSD – WSUB)

WD = mass of specimen in air (g)
WSSD = saturated surface dry mass (g)
WSUB = mass of specimen in water (g)

Bulk density, d = Gmb x ρw

At, Sample A 4.5%, Gmb =1141/(1170.9-656.6)=2.220

ρw = 2.220 x 1g/mm3 = 2.220

(Full result in table 12)

9.2.2 VOID IN TOTAL MIX (VTM)

The total volume of the small pockets of air between the coated aggregate particles
throughout a compacted paving mixture, expressed as a percent of the bulk volume of
the compacted paving mixture. The amount of air voids in a mixture is extremely
important and closely related to stability and durability. For typical dense graded
mixes with 12.5 mm (0.5 inch) nominal maximum aggregate sizes air voids below
about 3 percent result in an unstable mixture while air voids above about 8 percent
result in a water-permeable mixture.

26
 VTM= [1 – (Gmb /TMD)]*100

At, Sample A 4.5% VTM=[1-(2.220/2.433)]*100 =8.75%

(Full result in table 12)

9.2.3 VOIDS IN MINERAL AGGREGATES (VMA)

The volume of intergranular void space between the aggregate particles of a
compacted paving mixture that includes the air voids and the effective asphalt content,
expressed as a percent of the total volume of the specimen. When VMA is too low,
there is not enough room in the mixture to add sufficient asphalt binder to adequately
coat the individual aggregate particles. Also, mixes with a low VMA are more
sensitive to small changes in asphalt binder content. Excessive VMA will cause
unacceptably low mixture stability. Generally, a minimum VMA is specified and a
maximum VMA may or may not be specified.

VMA = 100 *(1- ( Gmb(1- Pb) / Gsb ))

Where,

Pb = Asphalt content, percent by weight of the mix

d = Bulk density
Gsb = Bulk specific gravity of the aggregate

At, Sample A 4.5% VMA = 100 *(1- ( 2.220(1- 0.045) / 2.6 ))=18.46%
(Full result in table 12)

9.2.4 VOIDS FILLED WITH ASPHALT (VFA)

The portion of the voids in the mineral aggregate that contain asphalt binder. This
represents the volume of the effective asphalt content. It can also be described as the
percent of the volume of the VMA that is filled with asphalt cement. VFA is inversely
related to air voids: as air voids decrease, the VFA increases.

VFA = [(VMA – VTM) / VMA]*100

At, Sample A 4.5 VFA = ((18.46 – 8.75) / 18.46)*100=52.82%

(Full result in table 12)

27
Sample Weight (gr) Specific Gravity Voids
% AC
No. Air Water Saturated Bulk Theoretical VTM VMA VFA
4.5 A 4.5 1141.8 656.6 1170.9 2.220 2.433 8.75 18.46 52.57
4.5 B 4.5 1132.8 650.4 1157.0 2.236 2.433 8.10 17.87 54.69
4.5 C 4.5 1139.3 653.1 1162.3 2.237 2.433 8.06 17.83 54.83
Ave. 4.5 1138.0 653.4 1163.4 2.231 2.433 8.30 18.05 54.14
5.0 A 5.0 1143.6 653.2 1162.1 2.247 2.416 7.00 17.90 60.92
5.0 B 5.0 1151.2 655.3 1172.6 2.225 2.416 7.91 18.70 57.73
5.0 C 5.0 1142.8 653.9 1160.5 2.256 2.416 6.62 17.57 62.31
Ave. 5.0 1145.9 654.1 1165.1 2.243 2.416 7.18 18.04 60.00
5.5 A 5.5 1153.4 653.2 1168.4 2.239 2.399 6.67 18.62 64.18
5.5 B 5.5 1146.6 651.2 1159.4 2..256 2.399 5.96 18.00 66.89
5.5 C 5.5 1147.9 650.3 1159.2 2.257 2.399 5.92 17.97 67.06
Ave. 5.5 1149.3 651.6 1162.3 2.251 2.399 6.18 18.20 65.93
6.0 A 6.0 1158.4 653.9 1170.7 2.241 2.382 5.92 18.98 68.81
6.0 B 6.0 1152.4 647.3 1157.2 2.260 2.382 5.12 18.29 72.00
6.0 C 6.0 1158.0 653.8 1165.5 2.263 2.382 4.99 18.18 72.52
Ave. 6.0 1156.3 651.7 1164.5 2.255 2.382 5.34 18.48 71.35
6.5 A 6.5 1157.1 647.6 1166.8 2.220 2.366 6.17 20.17 69.40
6.5 B 6.5 1164.2 657.4 1167.8 2.281 2.366 3.59 17.97 80.00
6.5 C 6.5 1160.1 654.1 1168.0 2.257 2.366 4.60 18.83 75.54
Ave. 6.5 1160.5 653.0 1167.5 2.253 2.366 4.79 18.99 74.74

Table 12: Results on density and void analysis (ASTM D2726)

28
 Bulk Density vs Percentage of Asphalt
2.26

2.255

2.253
2.25
Bulk Density, g/mm3

2.245

2.24

2.235

2.23

2.225
4 4.5 5 5.5 5.76 6 6.1 6.5 7
Percentage of Asphalt, %

Figure 19: Bulk density versus percentage of asphalt

VTM vs Percentage of Asphalt

9

8.5

7.5

7
VTM, %

6.5

6
5.75
5.5

4.5

4
4 4.5 5 5.5 5.76 6 6.5 7
Percentage of Asphalt, %

Figure 20: Voids in total mix (VTM) versus percentage of asphalt

 VMA vs Percentage of Asphalt
19.2

19

18.8

18.6
VMA, %

18.4
18.32
18.2

18

17.8
4 4.5 5 5.5 5.76 6 6.5 7
Percentage of Asphalt, %

Figure 21: Voids in mineral aggregate (VMA) versus percentage of asphalt

VFA vs Percentage of Asphalt

80

75

70
68.8
VFA, %

65

60

55

50
4 4.5 5 5.5 5.76 6 6.5 7
Percentage of Asphalt, %

Figure 22: Voids fill with asphalt (VFA) versus percentage of asphalt

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9.3 FLOW AND STABILITY ANALYSIS

Corrected
Average Height Marshall
Asphalt Marshall Flow
Sample height correlation stability
(%) stability (mm)
(mm) ratio (kN)
(kN)

A 69.72 0.86 - - -
B 67.98 0.9 7.73 6.96 3.41
4.5 C 68.72 0.88 8.78 7.73 5.21
Average 68.81 - 8.255 7.34 4.31
A 66.67 0.93 10.02 9.32 4.77
B 68.24 0.89 8.27 7.36 3.89
5.0 C 68.17 0.91 8.70 7.92 3.00
Average 67.69 - 9.00 8.20 3.89
A 67.47 0.93 - - -
B 66.59 0.94 9.17 8.62 3.77
5.5 C 66.43 0.93 8.27 7.69 3.17
Average 66.83 - 8.72 8.16 3.47
A 68.12 0.94 8.01 7.53 5.3
B 65.99 0.94 8.64 8.12 5.28
6.0 C 66.42 0.93 9.65 8.97 6.09

Average 66.84 - 8.77 8.21 5.56

A 68.08 0.9 7.87 7.08 4.05

B 65.95 0.94 8.19 7.70 5.88
6.5 C 66.21 0.94 7.73 7.27 3.82

Average 66.75 - 7.93 7.35 4.58

Table 13: Result of flow and stability

31
 Corrected Marshall stability (kN)
8.4

8.27
8.2
Corrected Stability, kN

7.8

7.6

7.4

7.2
4 4.5 5 5.5 5.76 6 6.5 7
Percentage of Asphalt, %

Figure 23: Marshall Stability versus percentage of asphalt

Flow vs Percentage of Asphalt

6

5.5

5
Flow, mm

4.5

4.3
4

3.5

3
4 4.5 5 5.5 5.76 6 6.5 7
Percentage of Asphalt, %

Figure 24: Flow versus percentage of asphalt

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9.4 RESILIENT MODULUS ANALYSIS

Resilient Modulus test is to measure the stiffness modulus of asphalt mixes by using MATTA
machine. The tests were carried out according to ASTM D4123.

Average
Asphalt Average Average Resilient
Diameter Height Resilient
Content Sample Diameter Height Modulus
(mm) (mm) Modulus
(%) (mm) (mm) (Mpa)
(Mpa)
102.78 69.46
A 101.82 102.10 69.60 69.72 2286
101.70 70.10
101.50 68.20
4.5 B 101.28 101.29 67.90 67.98 2560 2421
101.08 67.84
101.20 68.72
C 101.26 101.10 68.50 68.72 2416
100.84 68.94
101.88 66.72
A 102.74 102.50 66.62 66.67 3980*
102.88 66.66
101.38 67.96
5.0 B 101.78 101.61 68.44 68.24 2765 2738
101.68 68.32
100.06 68.52
C 101.18 100.77 67.60 68.17 2711
101.08 68.40
101.52 67.80
A 101.34 101.45 67.12 67.47 3324
101.50 67.50
101.38 66.92
5.5 B 101.26 101.30 66.78 66.59 3515 3419.5
101.26 66.08
100.88 66.48
C 101.18 101.03 66.22 66.43 2887*
101.02 66.60
100.92 67.36
A 101.18 101.06 68.50 68.12 3077
6.0 2762
101.08 68.50
B 101.42 101.15 65.68 65.99 2561

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 Average
Asphalt Average Average Resilient
Diameter Height Resilient
Content Sample Diameter Height Modulus
(mm) (mm) Modulus
(%) (mm) (mm) (Mpa)
(Mpa)
101.32 66.52
100.72 65.78
101.12 66.90
C 101.22 101.13 66.28 66.42 2649
101.04 66.08
101.56 68.00
A 101.48 101.55 68.10 68.08 2938
101.60 68.14
101.44 66.08
6.5 B 101.48 101.47 66.12 65.95 2925 2876
101.48 65.64
100.92 66.38
C 100.98 100.63 66.32 66.21 2765
100.00 65.92
*value not considered in calculation
Table 14: Result of Resilient Modulus

34
 Resilient Modulus vs Percentage of Asphalt
3600

3400

3200

3110
Resilient Modulus, Mpa

3000

2800

2600

2400

2200

2000
4 4.5 5 5.5 5.76 6 6.5 7
Percentage of Asphalt, %

Figure 25: Resilient Modulus versus percentage of asphalt

9.5 DETERMINATION OF OPTIMUM ASPHALT CONTENT (OAC)

Determination OAC using The Asphalt Institute Procedure. Get the data from the graph.

No. Graph Requirement % Asphalt Remark

(Clause 4.7.4)
1. Bulk density Peak of curve 6.10
2 VTM VTM equals to 3.5% Error Data above
3.5%
3. Marshall Stability Peak of curve 5.50
4. Flow Flow equals to 3mm Error Data above
3mm
5. Resilient Modulus Peak of curve 5.70

Table 15: Asphalt content for various properties

35
Calculation to get OAC:
OAC = (6.10 + 5.50 + 5.70) / 3 = 5.76
From the value of OAC, this data was obtained:

No. Graph Data from the Specification Remark

graph
1. VTM (%) 5.75 3-5 X
2. VMA (%) 18.32 Min. 16.5
3. VFA (%) 68.8 65-80
4. Marshall Stability (kN) 8.27 Min. 8
5. Flow (mm) 4.3 2-4 X
6. Resilient Modulus 3110 Min. 3000
(MPa)

Table 16: Requirement with the specification

10.0 CONCLUSION:
Based on the result, it is found that only four parameters does comply the specifications given
which are:

1. Voids in Mineral Aggregate (VMA)

2. Voids Filled with Asphalt (VFA)
3. Stability
4. Stiffness

Meanwhile, there are two parameters that do not comply with the specifications and are as
follows:

1. Voids in Total Mix (VTM)

2. Flow

* Two values in Resilient Modulus are not considered in the calculation since the values are
too far from the other values.

36
11.0 RECOMMENDATION:

Since there are numerous failures in the parameters, it is advisable to use the optimum binder
content and ideally compacted SMA.

Since VTM in our case is 5.75 which is quite higher than the specification (3-5), therefore we
should use more asphalt content to reduce the voids in total mix. Low air void contents
minimize the aging of the asphalt cement films within the aggregate mass and also minimize
the possibility that water can get into the mix, penetrate the asphalt cement film, and strip the
asphalt cement off the aggregate.

It is very important that the SMA be compacted to a laboratory density that approximates the
ultimate density achieved under traffic and at the same time have an air void content in 3 to 5
percent range. For ideal compaction we should compact the sample by applying 75 blows per
side in place of 50 blows.

37