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EVALUATION OF ACCOREX -
AN ASPHALT MIXTURE ADDITIVE
Report RF 4974
@] ~@[p@)~iJ .~
from the Texas A & M RESEARCH FOUNDATION
College Station. Texas
I Prepared for
S.P.C., Inc.
by
Texas Transportation Institute
Texas A&M University
February, 1984
EVALUATION
OF
ACCOREX - AN ASPHALT MIXTURE ADDITIVE
by
Davi d D. Hunter Research Associate
Joe W. Button Associate Research Engineer
Report RF 4974
Prepared for S.P.C., Incorporated
P.O. Box 188 Magnolia, Arkansas 71753
by
Texas Tran~portation Institute The Texas A&M University System College Station, Texas 77843
February, 1984
TABLE OF CONTENTS
LIST OF TABLES ................................................ LIST OF FIGURES
DISCLAIMER
............................................... ....................................................
ABSTRACT ...................................................... INTRODUCTION .................................................. ASPHALT CEMENT PROPERTIES .....................................
Gene ra 1 · .................................................. . Laboratory Test and Results ................................
AGGREGATE PROPERTIES .......................................... DETERMINATION OF OPTIMUM ASPHALT CONTENT ......................
Gene ra 1 · .................................................. . Mixing of Asphalt with Aggregate
Gyratory Compaction and Testing
........................... ............................
MIXTURE PROPERTIES ............................................ Gene ra 1 · .................................................. . Resilient Modulus
Hveem Stabil ity
.......................................... ............................................
Tensile Properties ....................................... Marshall Stability and Flow ................................ Discussion of Air Void Content ............................. Flexural Fatigue ...................................... Water Susceptibility .......................................
i
Page
iii
i v
v
vi
1
2
2
2
4
8
8
8
11
13
13
13
16
16
18
19
19
21
CONCLUSIONS •••.••••••••••••••••••••••••••••••••••••••••••••••• 28
REFERENCES .................................................... APPENDIX A - Test Results for Optimum Mixture Design
APPENDIX B - Resilient Modulus of Individual Specimens at Optimum Asphalt Content
APPENDIX C - Stability of Individual Specimens
.......... 29
10
33
at Optimum Asphalt Content ••••••••••••••••••••••• 35
APPENDIX D - Splitting Tensile Test Data at Optimum Asphalt Content.......................... 38
APPENDIX E - Flexural Fatigue Results of Individual Specimens ••••••••••••••••••••••••••••• 40
APPENDIX F - Freeze-Thaw Pedestal Results of Individual Specimens ••••••••••••••••••••••••••••• 45
i i
LI ST OF TABLES
Table
1 Physical Properties of Cosden AC-20 Asphalt •••••••••••• 3
2 Physical Properties of Rounded Gravel •••••••••••••••••. 5
3 Individual Components of the Design Gradation .......... 6
4 Optimum Mixture Properties of Gyratory Compacted Specimens •••••••••••••••••••••••••••••••••• 12
5 Physical Properties of Paving Mixtures With and Without Accorex •••••••••••••••••••••• ; ••••••••••• 15
6 Flexural Fatigue Results of Control and Accorex Modified Specimens ••••••••••••••••••••••••••• 22
7 Results of Moisture Tests •••••••••••••••••••••••••••••• 26
iii
LIST OF FIGURES
Figure
1 Project Design Gradation and Specification Limits •••••• 7
2 Test Program for Determining Optimum Asphalt Content ••••••••••••••••••••• ~................ 9
3 Test Program for Accorex and Control Mixtures Tested at Optimum Asphalt Content ••••••••••••••••••••••••••• 14
4 Resilient Modulus as a Function of Temperature.......................................... 17
5 Stress v~rsus Load Application to Failure for Control, Accorex Modified and Standard Accorex Specimens •••••• 23
6 Strain versus Load Application to Failure for Control, Accorex Modified, and Standard Accorex Specimens ••••• 24
iv
DISCLAIMER
The contents of this report reflect the views of the authors who
are responsible for the facts and the accuracy of the data presented
herein. The contents do not necessarily reflect the official views or
policies of Texas A&M University. This report does not constitute a
~tandard, specification or regulation.
v
ABSTRACT
Accorex, an additive for asphalt paving mixtures, was evaluated
by routine and special laboratory tests to measurl? its beneficial
effects on mixture properties. Standard tests were performed on a
control mixture and a similar mixture containing Accorex. Selected
tests were performed on mixtures containing equal volumes of binder.
Laboratory specimens were prepared using a common aggregate and these
paving mixtures were tested to identify characteristics such as
optimum asphalt content, stiffnl?ss, tensile properties, stability,
flexural fatigue resistance, and water susceptibility. In general, a
comparison of test results indicated improved performance for those
specimens containing Accorex.
vi
I NTRODUCTI ON
S.P.C., Incorporated is considering the feasibility of marketing
an additive for asphalt paving mixtures known as Accorex. Accorex is
a high quality polymeric resin 'with the potential for increasing
stability, tensile strength, ~nd crack resistance of asphalt paving
mixtures.
The objective of this research study is to compare physical
properties of asphalt paving mixtures containing Accorex with similar
mixtures containing no Accorex. Asphalt-aggregate mixtures were
prepared using a blended aggregate composed of a siliceous sub-rounded
river gravel, field sand, and limestone crusher fines. This report
describes properties of the asphalt, aggregates and paving mixtures
tested. Mixture tests included Hveem and Marshall stability,
resilient modulus, indirect tension and flexural fatigue test. Test
results yielded moderately higher values of tensile strength,
resilient modulus (at temperatures greater than 50oF), Marshall
stabi 1 i ty, and fat i gue res i stance for those mi xtu res conta i ni ng
Accorex. Thi sis i ndi cat i ve of improved res i stance to pa vement
rutting and cracking when Accorex is used in the prescribed manner.
1
i
ASPHALT CEMENT PROPERTIES
Gene ra 1
An AC-20 paving grade asphalt cement was selected for use in the
aspha It-aggregate mi xtures tested in thi s study. Thi s aspha lt was
produced by the American Petrofina refinery located near Big Springs,
Texas. It is normally considered to be highly temperature
,susceptible. It also exhibits above average hardening after heating
as compared to other paving grade asphalts. This asphalt is produced
from domestic crudes and, therefore, exhibits very uniform physical
and chemical properties. It is successfully used in the western
portion of the state of Texas.
Laboratory Test and Results
Standard laboratory tests (l, ~, l) were performed on the asphalt
and the results are presented in Table 1. The pu rpose of the
1 aboratory tests was to determi ne the bas i c phys i ca 1 cha racteri st i cs
of the asphalt.
2
Table 1. Physical Properties of American Petrofina AC-20 Asphalt.
Test Properties Resul ts
Viscosity, n° F, Poises 2.25 x 10 6
Vi scos ity, 140° F, Poises 1 ,910
Viscosity, 275° F, Poises 3.10
,Penetration, 39.2°F, (200gm/60sec) 13
Penetration, nOF, (100gm/5sec) 45
Softening Point, Ring and Sa 11 , of 119
Specific Gravity, 60°F 1.041
I Thin Film Oven Test,
Viscosity, 140°F, Poises 4,290
Penetration, nOF, dmm 32
Percent Penetration Retained 71
Rolling Thin Film Oven Test,
Viscosity, 140°F, Poises 5,350
Penetration, nOF, drrm 29
Percent Penetration Retained 64
3
AGGREGATE PROPERTIES
Basic physical characteristics of the aggregates used in this
research study are presented in Table 2. These values represent the
averaged results from standard laboratory tests performed on the three
di fferent aggregates that were blended together to produce des i gn
gradation. This design was in compliance with the Texas State
Department of Highways and Public Transportation (SOHPT) Type "0"
(Fine Graded Surface Course) specifications of mineral aggregates for
paving mixtures (i). A sub-rounded, siliceous gravel, was mixed with
field sand and limestone crusher fines to obtain the desired design.
The gradation of each individual aggregate is presented in Table 3
along with the percentages used in the blend. Table 3 also contains
the sieve analysis of the combined aggregates used to produce the
project design gradation. A graphical presentation of the Type "0"
specification limits and the project design gradation is presented in
Fi gure 1.
4
Table 2. Physical Properties of' Rounded Gravel.
Physical Property
Bulk Bulk Apparent Test Aggregate Specifi c Speci fi c Specifi c Absorption,
Designation Grading Gra vity Gravity Gravity percent (SSD)
ASTt~ + No. 4 C 127 Pea 2.632 2.654 2.683 0.72 AASHTO Grave 1 T 85
ASTM - No. 4 C 128 Pea 2.625 2.650 2.692 0.95 AASHTO Gravel T 84
ASTM C 128 Field 2.584 2.647 2.757 2.44 AASHTO Sand T 84
ASH1 Limestone C 128 Crusher 2.663 2.683 2.719 0.77 AASHTO Fines T 84
ASTM C 127 & 128 Project AASHTO Design 2.631 2.658 2.700 0.97
T 84 & T 85 Gradation
5
Table 3. Individual Components of the Project Design Gradation.
Limestone Siliceous Fi e 1 d Crusher Combined
Gra ve 1 Sand Fines Gradation Specifi ca ti on
Gradation pe.rcent passing
1/2-inch 100 100 100 100 100
3/8-inch 100 100 100 100 85-100
No. 4 51 100 100 65 32-79
No. 10 5 100 94 31 26-46
No. 40 2 99 52 20 8-62
No. 80 1 50 35 11 4-35
No. 200 1 8 19 4 1-8 ------
Percent Combined 70 + 10 + 20 = 100
6
100
• SDHPT Type "0" Specification L i mi ts T 90 .. Project Desi gn Gradation I
/ 80
f7 k--?O
C"' 70
bZ/ZX) fx?'>O J J~
I -1/ VX K>\?<2 kY>. 7 V'
Vl 60 r:o
50 I KX VX KXJ<'X' kX)< 7
I .3 3C o ~
20
10
/ /
/ /
------~~
7- //y
7 [7
V
.. J7 V
--~
Y X/\/ VxX / 7
/
---~ ---~ ~ y ~ -~ ~
o 80 40 10 200 100 50 30 1 6 8
Sieve NUfnber
/
J 'j 0
71 / T! [7 1 0
/ / I / I 20
7 1 !7 7 30
I 7 40
/ I 50
7 II 60
70
80
I 90
1/2" 1" 100
3/8" 3 / 4" 1 - 1 / 2"
Figure 1. Project Design Gradation Specification Limits.
7
"'0 Cl! C
ttl ...., Cl!
0::
...., c Cl! u "-Cl!
c...
E :::l U U <:
DETERMINATION OF OPTIMUM ASPHALT CONTENT
General
A flow chart showing the order in which tests were performed to
arrive at an optimum asphalt content is presented in Figure 2. The
method used to determine the optimum asphalt content was based on
Construction Bulletin C-14 (1) of the Texas SDHPT. In this method,
the pe rcent dens ity of the compacted aspha It-aggregate mi xtu res is
plotted versus the corresponding asphalt content used. A
best-fit-line is drawn through the plotted points. From past
observations of pavement performance, a density of 97 percent was used
to establish the optimum asphalt content. Data generated in this
phase of work are given in Table AI.
Mixing of Asphalt with Aggregate
As mentioned earlier the three different aggregates were blended
to form the project design gradation. Prior to mixing with asphalt,
the aggregates were placed in a 300 + SOF oven for a minimum of four
hours. The asphalt cement was heated to the same temperature. The
appropriate quantity of asphalt was added to the heated aggregate and
blended with a mechanical mixer. During this time, heat w~s applied
using a Bunsen burner to maintain the specified mix temperature in the
mixing bowl. When all aggregate particles were coated with asphalt
cement, the mixture was carefully divided into three aliquots of
predetermined weight and placed in an oven of appropriate compaction
8
Mix
an
d M
old
Bul
k H
veem
S
tore
24
3 Sp
ecim
ens
Spe
cifi
c
Sta
bil
ity
H
ours
I--
at e
ach
of
Gra
vi t
y AS
TM
at 7
7°F
the
5 B
inde
r AS
TM
D 1
560-
71
Con
tent
s by
D
272
6 G
yrat
ory
Com
pact
ion
Mar
sha
11
Ric
e A
ir V
oid
V~lA
an
d P
erce
nt
\0
Sta
bil i
ty
Spe
cifi
c C
onte
nt
Voi
ds
Fil
led
M
odif
ied
Gra
vi t
y AS
TM
Cal
cula
tion
s AS
TM
ASTM
D
320
3 D
155
9-73
D
204
1
Sel
ect
Opt
imum
A
spha
lt C
onte
nt
Fig
ure
2.
Tes
t Pr
ogra
m
for
Det
erm
inin
g O
ptim
um A
spha
lt
Con
tent
.
temperature. The batching and mixing operation was completed in
approximately four minutes.
The batching and mixing process for the specimens containing
Accorex was essentially the same with one exception. Prior to mixing
the asphalt and aggregate, Accorex was added to the hot aggregate and
blended. While the hot aggregate was being stirred, 0.8 percent (by
total weight of mix) of Accorex was sprinkled into the mixing bowl.
'This method produced a more uniform coating of the Accorex on the
aggregate than stirring the aggregate by hand. When mixed by hand the
mixture contained small aggregate clumps approximately 1/2 to 3/4 inch
in diameter. After sti rring the Accorex and aggregate for two
minutes, the appropriate amount of asphalt was added and the same
procedure as described earlier for the control mixture was followed.
Three observat ions were made whil e prepa ri ng the Accorex
mixtures. (1) A major portion of the Accorex added appeared to coat
the larger aggregate particles in the mix. (2) The addition of
Accorex apparently increased the viscosity of the mixture. (3) The
addition of Accorex improved the compactibility of this mixture. This
gravel mixture is normally tender and subject to plastic distortion in
the mold during compaction. The addition of Accorex toughened an
otherwise slightly tender mix and significantly improved the
compaction process.
Gyratory Compaction and Testing
Compact i on of the aspha It -aggregate mi xtu res was conducted in
accordance with Texas SDHPT test method TEX-206-F, Part II, "Motorized
10
Gyratory-shear Molding Press Operating Procedure" (}). This method
requires a compaction temperature of 250 ~ 50 F and produces 4-inch
diameter by 2-inch high specimens weighing approximately 1000 grams.
After compaction, specimens were allowed to cool before height and
wei ght measu rements were determi ned. The bulk specifi c gra vity of
each specimen was determined in accordance with ASTM 0 2726. Basic
properties of this mixture are given in Table 4.
Hveem stability of the specimens was determine in accordance with
the Texas SDHPT test method TEX-20B-F "Test for Stabilometer Value of
Bituminous Mixtures" (}). This is a modification of ASTM 0 1560 OJ.
Marshall stability tests were performed on the gyratory compacted
specimens. Since all of the specimens prepared for the determination
of optimum asphalt content were approximately 2-inches in height, the
measured stabilities were corrected to the standard height of
2.5-inches as per ASTM 0 1559 (l).
Some of the previously failed specimens were randomly selected
and used to determine the maximum specific gravity of the mixture in
accordance with ASTM 0 2041 "Maximum Specific Gravity of Bituminous
Paving Mixtures" (l).
11
Table 4. Optimum Mixture Properties of Gyratory Compacted Specimens.
Property
Design Asphalt Content, Percent by wt. of total Mix
Bulk Specific Gravity of Compacted Mixture
Maximum Specific Gravity of Mixture
Effective Specific Gravity of Aggregate
Asphalt Absorption, Percent by wt. of Aggregate
Effective Asphalt Content, Percent by wt. of total Mix
Voids in Mineral Aggregate, Percent Bulk Volume
VMA Filled with Asphalt, Percent Vr~A
Air Void content, Percent total Volume
12
Accorex Control
4.6 4.6
2.39 2.39
2.43 2.47
2.64 2.64
0.18 O. 16
4.4 4.4
14.0 13.2
87 77
1.8 3. 1
MIXTURE PROPERTIES
General
Asphalt concrete specimens were prepared at the optimum asphalt
content using gyratory compaction. Three were prepared containing
Accorex and three containing no Accorex. Additional specimens with
and without Accorex were prepared using the Marshall Compaction Method
as specified in ASTM D 1559 (l). Specimens were tested in accordance
with the program presented in Fi gure 3. A summary of mi xture
properties of the gyratory compacted specimens is presented in Table
5.
Resilient Modulus
Resilient Modulus (a measure of mixture stiffness) was determined
for each specimen at the specified temperatures listed in Table 5.
These values were obtained after a minimum time of 24 hours after
molding, using the Mark IV Resilient Modulus Device developed by
Schmidt (~). A diametral load of approximately 75 lbs was applied for
a duration of 0.1 seconds while monitoring the lateral deformation in
accordance with Schmidt (l).
Results on individual specimens are presented in Table B1 in
Appendix B. The values displayed in Table 5 are the averages of the
three specimens tested. The specimens containing Accorex exhibited
higher stiffness values at temperatures higher than 50oF. Test
results further indicated that the addition of Accorex decreased the
temperature susceptibility of the mixture. To illustrate this,
13
:"-
~,.
,._
-.'''.
,'
Gyr
a to
ry
Res
ilie
nt
Hve
em
Sto
re
Sp
litt
ing
C
ompa
cted
M
odul
us
f-
Sta
bi 1
ity
-24
H
ours
f--
Ten
sile
Sp
ecim
ens
at -
10,
ASTM
a t
77
°F
Tes t
at
33,
68
o 15
60
77°F
an
d 6
tota
1
and
104°
F 2
in/m
in
.~ B
ulk
_ R
esil
ien
t R
ice
-A
ir V
oid ~
VMA
and
Spe
cifi
c M
odul
us
Spe
cifi
c C
onte
nt
Per
cent
Voi
ds
~
I G
ravi
ty
-at
77°
F G
ravi
ty
-A
Sm
f---
Fil
l ed
ASTM
'---
.. -
ASTM
o
3203
C
alcu
lati
ons
o 27
26
o 20
41
~Iar
sha
11
Mar
sha
11
Com
pact
ed
Sta
bi 1
ity
Sp
ecim
ens
and
Flow
6 to
ta 1
-
Fig
ure
3.
Tes
t Pr
ogra
m
for
Acc
orex
an
d C
ontr
ol
Mix
ture
s T
este
d at
Opt
imum
Asp
halt
Con
tent
.
-'
U1
Tab
le 5
. P
hysi
cal
Pro
pert
ies
of P
avin
g M
ixtu
res
With
an
d W
ithou
t A
ccor
ex*.
Pro
pert
ies
of
Spec
imen
s T
este
d
Mix
ture
Pro
pert
i es
Sta
bil
ity
Res
ilie
nt
Mod
ulus
,
psi
x 10
3
Ind
irec
t
Ten
sion
Sam
ple
Hei
ght
inch
es
Bul
k S
peci
fic
Gra
vity
Ric
e S
peci
fic
Gra
vity
Air
Voi
ds,
perc
ent
Hve
em S
tab
ilit
y,
perc
ent
Mar
shal
l S
tab
ilit
y,
lbs
Mar
shal
l Fl
ow,
0.01
in
.
Tes
ted
@ 1
04°F
T
este
d @
nO
F
Tes
ted
@ 68
°F
Tes
ted
@ 3
3°F
Tes
ted
@ -
10°F
Ten
sile
Str
engt
h,
psi
Str
ain
at
Fai
lure
, in
/in
Sec
ant
Mod
ulus
, ps
i T
ough
ness
lb
-in
/in
3
Gyr
ator
y C
ompa
cted
Sp
ecim
ens
AC
wit
h AC
CORE
X
2.07
2.39
2.43
1.6
27
100
750
1,06
0
2,05
0
2,96
0
190
0.00
34
55,7
00
0.55
AC
Sta
ndar
d
2.07
2.39
2.47
3.2
28 40
540
860
2,13
0
3,03
0
150
0.00
40
36,8
00
0.52
* Eac
h va
lue
repr
esen
ts
the
aver
age
of
3 sp
ecim
ens.
r~ar
shal
l C
ompa
cted
Sp
ecim
ens
AC
wit
h AC
CORE
X
2.53
2.37
2.43
2.6
2360
9
1180
AC
Sta
ndar
d
2.51
2.39
2.47
3.
4
1980
8 910
resilient modulus was plotted as a function of temperature in Figure
4. Although there are no field performance data to substantiate this
statement, these data seem to indicate that the addition of Accorex to
this paving mixture will improve its resistance to cracking and
rutting.
Hveem Stabi 1 ity
The Hveem stability test was developed in the late 1930's by the
California Division of Highways. The Hveem stability value is a
measure of a paving mixture's ability to resist plastic flow. The
value is primarily a measure of interparticle friction and, is
therefore, strongly dependent on the angularity of the aggregate
utilized.
The speci mens conta i ni ng Accorex exhi bi ted Hveem stabi 1 it i es
approximately equivalent to those of the control specimens (Table 5).
This result is not surprising since both mixtures used identical
aggregates. Test results on individual specimens are given in Table
C1 of Appendix C.
Tensile Properties
Tens i 1 e propert i es of the gyratory compacted speci mens were
examined using the indirect tensile test (~). Specimens were tested
at 77 0 F with a loading head displacement rate of 2-inches per minute.
Test results for individual sepcimens are presented in Table 01 in
Appendix D.
16
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m
. =)
t:.I
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at '
U7
f
#t
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$ '6
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'tt*
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tztt
rt ',
(UP
. ,t
i&t"
V,i
rt"i
M1
:i i:
¥lcH
l;j ..
. a.' .
....
. ~.
l~ E
=t
5 3 2 1 0
.8
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5 0 ><
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til
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2 ti
l ~
~
-0
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O. 1
::E
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J
0.08
t:
(]
J 'r
-
'r-
0.05
ti
l
0.03
t -
Con
trol
(]
J EI
0
::
0 -
Acc
orex
0.02
0.01
-20
o 20
40
60
80
10
0 12
0
Tem
per
atu
re,
OF
Fig
ure
4
. R
esi
lien
t M
odul
us
as
a F
un
ctio
n o
f T
empe
ratu
re.
A summary of these data (Table 5) indicates that the addition of
Accorex resulted in a 27 percent increase in tensile strength.
Toughness (Table 5) of the paving mixture was estimated by computing
the area under the stress-strain curves to the point of specimen
failure. Those specimens containing Accorex exhibited slightly higher
values of toughness. The higher values of tensile strength and
toughness are indicative of improved resistance to cracking when
Accorex is added.
Marshall Stability and Flow
The Marshall test was developed in the late 1930's and early
1940's by the Mississippi State Highway Department and the U.S. Army
Corps of Engineers. Marshall stability and flow values of an asphalt
concrete material are measures of the materials ability to resist
plastic flow. Unlike Hveem stability, Marshall stability is more
dependent on the propert i es of the bi nder and 1 ess dependent on
interparticle friction of the aggregate.
Results for each individual specimen are presented in Table C2 in
Appendix C. Specimens containing Accorex exhibited approximately 20
percent higher stability values than the control with only a neglible
increase in plastic flow. This indicates that the addition of Accorex
to this paving mixture will reduce the probability of rutting, shoving
and corrugations.
18
Discussion of Air Void Content
One of the most noticeable effects of Accorex on the mixture was
the reduction in the air void content (Table 4). The addition of
Accorex resulted in a reduction in air voids of approximately 50
percent. A change in air void content of this magnitude alone will
substantially change the properties of a compacted asphalt mixture.
Therefore, the decision was made to compare the Accorex and control
specimens on an equivalent air void basis for the remainder of the
test program. The most practical method to accomplish this was to
design the mixtures using an equal volume of binder. (Binder is
defi ned as ilspha It cement or aspha lt pl us Accorex.) A specifi c
gravity test was performed on the Accorex material and the value was
found to be approximately 0.91. Calculations were then made to
determine the required reduction in asphalt cement for those specimens
containing Accorex. Essentially, the specimens containing Accorex
requi red 0.9 percent less asphalt than the control specimens. They
will be referred to as the modified mixture throughout the remainder
of the report. Control and modified mixtures were prepared and tested
for beam fatigue and water susceptibility.
Flexural Fatigue
Beam fatigue tests were performed on the control and the modified
Accorex specimens at three stress 1 evel s and on standard Accorex
specimens at one stress level to provide information for the
prediction of fatigue life of pavements using these mixtures. Fatigue
19
cracking of pavements appears in patterns similar to "chicken wire" or
"alligator skins". This is the origin of the term alligator cracking.
Thi s type of cracki ng is due to repeated wheel loads; it norma lly
begins in the wheel path.
The beam fatigue testing apparatus applies loads at the third
points of the beam, four inches on center, through one inch wide steel
blocks. The applied load is measured by a load transducer and
continuously recorded on an oscillographic recorder. Linear variable
differential transformers (LDVT) measure the specimen deformation at
the center of the beam. This deformation is also recorded on the two
channel oscillographic recorder. The machine is operated in the load
control mode with half-sine wave form at a frequency of 100 cycles per
minute and a load duration of 0.1 seconds. A reverse load is applied
at the end of each cycle to insure that the specimen will return to
its original at-rest position after each cycle. It is necessary to
periodically tighten the specimen loading and holding clamps as a
result of plastic flow of the asphalt concrete. Upon rupture of the
speci men, 1 i mit swi tches shut off the testing machi ne, and a cyc 1 e
counter indicates the number of cycles to complete rupture.
Peak stress, initial bending strain (bending strain @ the 200th
cycle), initial stiffness modulus (@ the 200th cycle). and estimated
total input energy were calculated for each fatigue test specimen in
accordance with the formul ae gi ven in Appendi x E. The tota 1 input
energy is a measure of energy imparted to the specimen during testing
20
to failure. Table EI and E2 give the results of the calculations for
individual beams tested and Table 6 gives a statistical summary of
those tests conducted at the low, medium, and high stress levels.
The Accorex modified specimens exhibited fewer total load cycles
to failure, lower initial stiffness modulus, and less total energy
input than the other specimens (Table 6). Fatigue test results are
plotted in Fi gures 5 and 6. Based on these fat i gue test results,
Accorex modified specimens would most likely exhibit fatigue cracking
earlier than the other specimens when tested at stress levels above
IOOpsi.
Fatigue test results of the standard Accorex specimens exhibited
improved fatigue performance (Table 6). The number of load cycles to
failure, initial stiffness modulus and total energy input were
dramatically increased by the addition of Accorex. It should also be
pointed out that the air void content of the Accorex specimens was
reduced by approximately 50 percent and, further, that an increase in
asphalt content of a paving mixture will also improve fatigue
performance, however, mixture stability will be decreased.
Nevertheless, the addition of Accorex to an asphalt mixture without
reducing the asphalt content will significantly improve the resistance
of an asphalt paving mixture to traffic-induced cracking.
Water Susceptibility Study
The "Texas Boiling Test" C~) was performed to evaluate the
effects of Accorex on moi stu re suscept i bil ity of aspha lt pa vi ng
mixtures. Mixtures were prepared and tested in accordance with the
21
I I '!
Table 6. Flexural Fatigue Results of Control and Accorex Modified Specimens.
1·1 a x i mum l3~nlJi n'l Ini t i ill T () t,ell Specific Air Input Strain at Cycles Sti ffness Energ;
Sample Stress Gravity, Voids, Stress, 200 Cycles, to Hodulus, Input, Type Level Statistic gm/ cc percent psi in/inxlO- 4 Fai lure psi lb-in
Mean 2.473 5.5 98 1.8 266,800 566,400 53,700 Low Std. Dev. 0.002 0.34 3.2 0.3 130,700 94,000 28,SOO
Coef. Val" . 0.8 6 3 17 49 17 54
~iean 2.473 5.8 154 2.8 38,100 545,200 19,100 Control r~edium Std. Dev. 0.002 0.40 1l.5 0.2 8,800 26,700 4,00Cl
Speci~en5 Coef. Va r. 0.8 7 8 8 23 5 21
I~ean 2.473 5.5 182 3.2 27,300 597,400 18,600 High Std. Dev. 0.002 0.20 8.1 0.5 20,100 105,000 II ,800
Coef. Var. O.S 4 4 15 73 18 63
I·lean 2.466 5.7 106 2.2 137,400 440,700 36,900 Low Std. Oev. 0.003 0.17 6.3 0.2 65,000 18,400 18,200
Coef. Var. 0.1 3 6 7 47 4 49
::odified liean 2.466 5.7 155 3.5 20,200 473,000 14,000 Accorex 1'ledi um Std. Dev. 0.003 0.31 9.0 0.5 7,500 72,144 7,000
Specimens Coef. Va r. O. 1 5 6 15 37 15 50
I·lean 2.466 5.9 183 4.3 4,800 470,800 5,200 High Std. Dev. 0.003 0.23 18.4 1.3 1,300 110,000 2,700
Coef. Va r. O. 1 4 10 29 27 23 53
Standard !':ean 2.434 2.7 159 2. 1 359,300 797,900 ' 1: ~ 1...; I • ~ :) Accorex ~'~ediur1 Std. On) . 0.009 0.3 1.7 0.6 150,500 240,600 71, 2 0 Speci~e'ls Coef. Var. 0.4 11 1 26 42 30 2
22
."·m
t-:)}
;, .+:
!i9it'
n iIi"
....
lS'..
,;,~M:
i't'.W
_*
5
. ",h
.. n
e>
of *.
, • .
. ·'.
H'.
ao
,....
....,"'
H·,,
_",..
'" K
......... ,'<
Ie
.,,,,,,,
,.,_> ..
;,,,;,,,,
_ ;"
«"',&
0'-
;1>
'+..i
**-
" ...
....
. ·.;
Yrt
1''''''
a ~
VI
0..
b
C/)
C
/)
w
0::::
l-
N
C/)
w
l- =>
0..
~
.....
103E~---
o --
Con
trol
~ --
Acc
orex
r,1
od.
102
o -.-
Std
. A
ccor
ex
-------
--0 -0
--
__
--------0
--_
-~
10 10
2
Acc
orex
Mod
ifie
d -
N f
= 3
.06
x 10
17
(1/0
)6.0
71,
R2
= 0
.98
Con
trol
-
N f
= 1
.36
x 10
13
(1/0
)3.8
76,
R2
= 0
.98
103
104
LOAD
APP
LICA
TIO
NS
TO
FAIL
URE
(Nf)
10
5
Fig
ure
5.
Str
ess
vers
us
Load
A
ppli
cati
ons
to
Fai
lure
fo
r C
ontr
ol,
Acc
orex
Mod
ifie
d,
and
Sta
ndar
d A
ccor
ex
Spec
imen
s.
106
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
----
......
...
t:
.,....
......... ~
,....
..-...
w
'-
"
z ...... ~
a:
I-
Vl
~
Z ......
N
0 +:
> ~
w
cc
-oJ ~
......
l- ......
z ......
10-3
IE
-----
t
----~ 0
--
--
Con
trol
I b.
--
Acc
orex
r~od.
r 0 ---
Std
. A
ccor
ex
~
~
----
-0
---
- -10
-4 t
Acc
orex
M
odi f
i ed
N f =
1.2
3 x
10-1
3 (1
/E}4
.948
, R2
=
0.9
8
N f
= 1
. 11
x
1 0 -1
0 (1
/ d 4
. 1 04
, R2
C
ontr
ol
0.99
10-5
• • ..
1 ••• 1
.,1
..•.
1
102
103
104
105
106
LOAD
APP
LICA
TIO
NS
TO
FAIL
URE
(Nf)
Fig
ure
6.
Str
ain
ver
sus
Load
A
ppli
cati
ons
to
Fai
lure
fo
r C
ontr
ol,
Acc
orex
Mod
ifie
d,
and
Sta
ndar
d A
ccor
ex
Spec
imen
s.
I J l
f ~
f i i I
J
I I
I
I f
test method TEX-530-C of the Texas (SDHPT) (~). Test results are reported in Table 7.
The mixtures were placed in a stainless steel beaker of boiling
distilled water for 10 minutes. After removal of all stripped asphalt
from the surface of the water, the mixtures were poured into shallow
pans and allowed to dry. Visual observation was made of the mixtures
before and after boiling and the degree of stripping was estimated.
Modif.ied Accorex and control mixtures exhibited approximately 10
percent stripping. This indicates that the addition of Accorex had no
effect on moisture susceptibility of this particular asphalt mixture.
A new but very sens it i ve test ca 11 ed the freeze-thaw pedesta 1
test was a 1 so performed to determi ne the effects of Accorex on
moisture susceptibility of asphalt concrete.
The size of the aggregate used in the freeze-thaw pedestal test
was between a No. 20 and a No. 35 sieve. Use of the uniformly sized
material minimized the effect of aggregate interlock while maximizing
the effects of bond between the aggregate and the asphalt cement. Of
course, the optimum asphalt content for this mixture was different
from the previ ous ly di scussed mi xtures. The control specimens
contained 6.6 percent asphalt by total weight of the mix and the
mOdified Accorex specimens contained 5.6 percent. The mixtures were
compacted into briquets O.75-inches in height and 1.6-inches in
di ameter. The bri quets were then cured for three days, pl aced on a
beveled stress pedestal, submerged in distilled water in a small jar,
and place in a controlled temperature environment at OOF for 14
25
N
0'\
..........
... -_ ...
....
Tab
le
7.
Res
ults
o
f M
oist
ure
Tes
ts
for
Con
trol
an
d A
ccor
ex
Mod
ifie
d Sp
ecim
ens.
Free
ze-T
haw
P
edes
tal
Tes
t T
exas
B
oili
ng
Tes
t M
axim
um
Num
ber
of
Spe
cifi
c A
ir
Cyc
les
Deg
ree
of
Sam
ple
Gra
vi t
y ,
Voi
ds
, to
S
trip
pin
g,
Type
S
tati
stic
gm
/cc
perc
ent
Fai
lure
pe
rcen
t M
ean
2.44
0 26
.7
1 10
C
ontr
ol
Std
. D
ev.
0.01
0 0.
06
0 --
Coe
f. V
ar.
0.4
0.2
0 --
Mea
n 2.
413
26.4
2
10
Acc
orex
S
td.
Dev
. O
.OlD
0.
35
0.6
--C
oef.
Var
. 0.
4 1
25
--
t i l
1 J
I 1 1
I i I 1
1 1 I
I 1
hours. After thawing in 77 0 F water for 45 minutes, the jars were
placed in a controlled temperature environment at 1200 F for 9 hours.
Test results on individual specimens are given in Table Fl in Appendix
F and a statistical summary is presented in Table 7.
The Accorex modified specimens failed after two cycles whereas
the control specimens fai led after only one cycle of the freeze-thaw
procedure. From past research (2.), it appears that those
asphalt-aggregate mixtures exhibiting high stripping potential will
fail in less than 10 cycles and those exhibiting low stripping
potential will require more than 50 cycles to produce failure. The
test results indicate, therefore, that the addition of Accorex to this
mixture does not significantly affect moisture susceptibility.
27
---------
1
I CONCLUSIONS
I I
I Based on a laboratory investigation of Accorex, an additive for
asphalt paving mixtures, the following conclusions appear warranted:
J i ! ,
1. Marshall stability of an asphalt mixture will be increased by
the addition of Accorex. This indicates improved resistance
to plastic flow (that is, rutting, Shoving, etc),
2. Hveem stability of an asphalt mixture is not appreciably
affected by the addition of Accorex,
3. Addition of Accorex to asphalt-aggregate mixtures will
substantially reduce the air void content,
4. The addition of Accorex will increase tensile strength and
stiffness of asphalt concrete mixtures which may be
indicative of improved resistance to cracking and rutting,
5. Addit i on of Accorex wi 11 decrease mi xtu re temperature
susceptibility which may also be indicative of improved
resistance to cracking and rutting,
6. The addition of Accorex to an asphalt mixture will
significantly improve its resistance to traffic-induced cracking and
7. Accorex will not signficant1y affect an asphalt mixture's
resistance to moisture damage.
28
, I ~ I J
j i
REFERENCES
1. Annual Book of Standards, Part 15, Road and Paving Materials;
Bituminous Materials for Highway Construction, Waterproofing, and Roofing and Pipe; Skid Resistance, American Society for Testing and Materials, 1916 Race St., Philadelphia, PA, 1977.
2. Standards Specification for Transportation Materials and Methods of Sampling and Testing, Part II, American Associatlon 0
State Highway and Transportation Officials, 444 N. Capital St. N.W., Washington, D.C., 1974.
3. Manua 1 of Test i ng Procedures, Vol. 1, Texas State Depa rtment of Highways and Public Transportation, Austin, Texas, 1982.
4. Standard Specifications For Construction of Highways, Streets and Bri dges, Texas State Depa rtment of Hi ghways and Pub 1 i c Transportation, Austin, Texas, 1982.
5. Construction Bulletin, C-14, Texas Highway Department Construction Division, Austin, Texas, 1968.
6. Schmidt, R. J., "A Practical Method for Measuring the Resilient Modulus of Asphalt-Treated Mixes", Highway Research Record No. 404, Highway Research Board, 1972.
7. Schmidt, R. J., "Operating Instructions for the Mark IV Resilient Modulus Device", An operations manual.
8. Hadley, W.O., Hudson, W. R., Kennedy, T. W., "Evaluation and Prediction of the Tensile Properties of Asphalt-Treated Materials", Research Report No. 98-9, Center for Highway Research, University of Texas at Austin, May, 1971.
9. Kennedy, T. W., Roberts, F. L., Lee, K. W., Anagnos, J. N., "Texas Freeze-Thaw Pedestal Test for Evaluating MOisture Susceptibility for Asphalt Mixtures", Research Report No. 253-3, Center for Transportation Research, University of Texas at Austin, February, 1982.
10 • I rw in, L. H., " E val u a t ion 0 f S tab i 1 i zed So i 1 sin F 1 ex u r a 1 Fat i g u e for Rational Pavement Design", Doctorial Dissertation, Texas A&M University, May, 1973.
29
APPENDIX A
Test Results for Optimum Mixture Design
30
t .....
-.',
,'
....
----
.•• "
. _
....
....
"
~. __
......
......
.. _
....
. " .
....
....
... "
.",.
,)"
';"_
~'
'ed
....... '
........ ..
w
-
Tab
le
1\1.
D
ata
Sum
mar
y o
f O
ptim
ulll
Mix
ture
D
esig
n.
Asp
halt
C
onte
nt,
perc
ent
by w
t. 3.
5 4.
0 4,
.5
5.0
5.5
of
dry
Agg
rega
te
Bul
k S
pec
ific
Gra
vity
of
Com
pact
ed
2.31
1 2.
364
2.37
2 2.
397
2.40
3 M
i xtu
re
Max
imum
Spe
cifi
c G
ravi
ty o
f 2.
511
2.49
3 2.
478
2.46
0 2.
446
Mix
ture
Eff
ecti
ve
Spe
cifi
c G
ravi
ty o
f 2.
642
2.64
2 2.
642
2.64
2 2.
642
Agg
rega
te
Asp
halt
Abs
orpt
ion.
pe
rcen
t by
wt.
O. 1
6 O.
16
0.16
0.
16
O. 1
6 o
f ag
greg
a te
Eff
ecti
ve
Asp
halt
Con
tent
, pe
rcen
t 3.
3 3.
8 4.
3 4.
8 5.
3 by
w
t. o
f ag
greg
ate
Voi
ds
in M
iner
al
Agg
rega
te,
Per
-15
.2
13.7
13
.7
13.3
13
.4
cent
bul
k vo
lum
e
VMA
Fil
led
wit
h A
spha
lt.
perc
ent
47
62
69
80
87
VMA
Air
Voi
d C
onte
nt.
perc
ent
tota
l 8.
0 5.
2 4.
3 2.
6 1.
8 vo
lum
e
Hve
em S
tab
il it
y
29
33
32
28
28
Mar
shal
l S
tab
ilit
y*
. lb
s 79
0 96
0 94
0 1.
080
1.03
0 M
arsh
all
Flow
*.
0.01
in
ch
13
13
15
17
17
* The
se
valu
es w
ere
obta
ined
fr
om
the
aver
ages
o
f tw
o te
sts.
A
ll o
ther
val
ues
list
ed i
n T
able
Al
ar
e av
erag
es
of
thre
e te
sts.
I
Aschalt Content (~) Bul k Sp. Gr. :~ax. So. Gr. De~sity (,) Hvee~
Mix. By Tota 1 By Total of Specimens of SDecimens Gb • 00" S ta b i 1 i ty
~lo . ';eight Weight of Agg. (Gb) (Gm) -;::- x J .J
" u;7l .. 3.4 3.5 2.311 2.511 92.0 29
2 3.8 4.0 2.364 2.493 94.8 33
3 4.3 4.5 2.372 2.478 95.7 32
4 4.8 5.0 2.397 2.460 97.4 28
5 5.2 5.5 2.403 2.446 98.2 28
100
t 98
1 ~ 96 >, ..... Vl 94 c ClJ
0 92
90
1 50 l
I 40
I -~ 30
i >, ..... J ~ 20
.D "0 .....
VI 10
0 2.0 3.0 4.0 5.0 6.0
Aspha It Content ('I by Total Weight)
I ,J
Optimum Resu lts
,f\s [2 ha It Content ( '~ ) Hveem By Total By Total Dens ity Stability Weight Weight of Agg. ( on ( c; 2
4.6 4.8 97 30
Figure Al. Selection of Optimum Asphalt Content.
32
j
j I
i
I APPENDIX B
Resilient Modulus of Individual Specimens at
Optimum Asphalt Content
33
Table 81. Resilient Modulus of Gyratory Compacted Specimens.
I Resilient Modulus, psi x 103
Sample Test Temperature Type Number -lOoF 33°F 68°F nOF 104°F
ACC-l 3,040 1,965 990 741 98
Accorex ACC-2 2,674 2,153 1 ,011 723 103
ACC-3 3,154 2,040 1 ,180 no 106
LS-l 3,021 2,260 862 540 39
Contro 1 LS-2 3,139 2, 172 865 495 . 34
LS-3 2,920 1,961 860 580 37
Table B2. Resilient Modulus of Marshall Compacted Specimens.
I Resilient Modulus, Sample psi x 103
Type Number nOF
ACC-M1 1 , 148
Accorex ACC-M2 1 ,201
ACC-~~3 1 .202
LS-~11 863
Control LS-M2 914
LS-M3 941
NOTE: Values listed on both tables are average of two or more tests.
34
APPENDIX C
Stability Results of Individual Specimens at
Optimum Asphalt Content
35
Table C 1 . Individual Stability results of Gyratory Compacted Specimens.
Bulk Air Hveem Sample Height, Specific Voids, Stabil ity ,
Type Number in. Gravity percent percent
ACC-l 2.070 2.389 1.8 31. 7
Accorex ACC-2 2.068 2.392 1.7 23.5
ACC-3 2.064 2.391 1.8 24.7
LS-l 2.071 2.392 3.2 28.2
Control LS-2 2.074 2.383 3.5 30.0
LS-3 2.060 2.405 2.6 25.6
NOTE: Values listed above are average of three or more tests.
36
i
I I I
Table C2. Individual Marshall Stability results of Marshall Compacted Specimens.
Bulk Air r·1arshall Marshall Sample Hei ght, Specific Voids, Stabi 1 ity, Flow, Type Number in. Gravity percent lbs 0.01 in.
ACC-Ml 2.547 2.350 3.5 2,259 10 Accorex ACC-t'12 2.513 2.374 2.5 2,391 9
ACC-M3 2.517 2.372 2.5 2,424 8
LS-r11 2.517 2.380 3.6 2,058 6 Contro 1 LS-M2 2.502 2.387 3.4 1,858 8
LS-M3 2.501 2.395 3.0 2,019 9
NOTE: Values listed are averages of three tests.
37
I
I
I
j
I . I
f I
I I
APPENDIX D
Splitting Tensile Test Data at Optimum Asphalt Content
38
I I l
I
Table 01. Splitting Tensile Test Data.
Ultimate Ultimate Secant Sample Stress,* Strain,* Modulus,*
Type Number psi i n/ in psi
ACC-1 184 0.0036 51 ,700
Accorex ACC-2 187 0.0033 57,400
ACC-3 199 0.0034 58,100
LS-l 145 0.0038 38,400
I Contro 1 LS-2 141 0.0044 32,100
*
LS-3 156 0.0039 39,900
All samples were tested at 77°F (25°C) at a rate of 2.0 in/min and all values were measured at point of failure and represent averages of two or more tests.
39
Toughness
lb-in/in 3
0.544
0.510
0.605
0.506
0.542
0.508
APPENDIX E
Flexural Fatigue Results of Individual Specimens
40
Summary of Formulae
for
Third-Point Loaded Beam (lQ)
P/Z PIZ
1 I r-b-1 01
_~L/J~L/) P/l I
I , I L/J~.
PIZ
Peak stress in extreme fi ber = PL ;; bh2 ' psi
Initial stiffness modulus 0.213 PL 3 = E = +
W bh 3 o
psi
Initial bending s t ra in in extreme fi ber = _ cr
E - E (Hooke's Law)
10.2 P W o Nf Total input energy = Uf = in.-lb 23 ,
I'lhere P = appned load, lbs
L = tested length of beam, in.
b = width of beam, in.
h = depth of beam, in.
0.400 PL (l+~) , W bh o
, in./in.
~'Jo = center deflection of beam at 200th cycle, in.
u = Poisson's ratio (assumed 0.35)
Nf = number of cycles to failure
41
Equation llo.
(01 )
(02 )
(03)
(04)
~ ....
. . ..
..-.
-..
, .....
---.
. ........
_-......
.._--, ...
. _ ...
~~-
-.-.~ ..
-
Tab
le
E1.
Indi
vidu
al
Beam
F
atig
ue T
est
Res
ults
on
the
Con
trol
Sp
ecim
ens.
~
N
Cyc
les
Str
ess
Sam
ple
Sam
ple
to
Lev
el
Num
ber
~t.
(in
)*
Fai
lure
C-T1
3.
0 22
5,47
5
C-2
3.
0 16
9,12
6 Lo
w C
-5
3.0
459,
790
C-8
3.
0 21
3,11
6
C-3
3.
0 46
,528
Med
ium
C
-6
2.9
28,9
62
C-9
3.
1
38,9
19
C-4
3.
0 13
,599
Hig
h C
-7
3.0
18,0
62
C-1
0 3.
0 50
,390
* Wid
th
of
beam
sp
ecim
ens
was
3-
inch
es.
Ben
ding
In
itia
l A
vera
ge
Str
ain
M
odul
us
(E)
Inpu
t at
the
at
the
Str
ess,
20
0 cy
cle,
20
0 cy
cle,
ps
i in
/in
x
10-4
ps
i
97
1.5
635,
568
97
2.2
435,
253
99
1.8
56
1 ,3
27
100
1.6
633,
369
152
2.9
524,
071
167
2.9
53
6,25
0
144
2.5
575,
178
179
3.8
47
6,18
4
184
3.0
656,
125
185
2.9
65
9.94
1
TotaE
In
put
Ene
rgy
at
the
200
cycl
e,
in
-lb
37,4
00
41,0
00
96,8
00
39,8
00
23,6
00
16,1
00
17,7
00
I
'11 ,
300
12,3
00
32.2
00
~ .... ~---------
--_ ..... -
----
~~.
Tab
le
E2.
Indi
vidu
al
Beam
F
atig
ue T
est
Res
ults
on
Acc
orex
Sp
ecim
ens
Con
tain
ing
App
roxi
mat
ely
1%
Les
s A
spha
lt
than
th
e C
ontr
ol
Spec
imen
s.
Ben
ding
In
itia
l T
ota
1 A
vera
ge
Str
ain
M
odul
us
(E)
Inpu
t E
nerg
y C
ycle
s In
put
at t
he
at t
he
at t
he
Str
ess
Sam
ple
Saln
r 1 e
to
Str
ess,
20
0 cy
cle,
20
0 cy
cle,
20
0 cy
cle,
L
evel
N
umbe
r H
t. (i
n)*
Fa
i 1 u
re
ps i
in/i
n x
10-
4 ps
i in
-
1 b
ACC-
T1
3. 1
15
0,22
3 10
3 2.
1
455,
063
37,5
00
ACC
-2
3.0
215,
477
108
2.3
43
4,03
9 58
,700
Lo
w A
CC-5
3.
1
125,
878
103
2.4
41
7,59
5 37
,200
+::
> A
CC-8
3.
1
58,1
19
w
106
2. 1
45
6,08
5 14
,200
ACC
-3
3.0
26,9
44
165
3.9
459,
692
21,8
00
Med
ium
A
CC-6
3.
1
21,6
50
149
2.9
550,
871
12,1
00
ACC
-9
3. 1
12
,070
15
3 3.
7 40
8,43
5 12
,100
ACC
-4
3.0
5,10
5 19
9 5.
5 42
0,47
3 7,
700
Hig
h A
CC-7
3.
1
3,32
7 17
3 3.
0 59
6,92
5 2,
200
ACC
-10
3. 1
5,
820
176
4.5
395,
037
5,60
0
* Wid
th
of b
eam
spe
cim
ens
was
3-
inch
es.
--..... -.... -
--.~~-----. ---
-_ ...
. -.-
.. -" ..
......
.. -...
..
+:>
+:>
Tab
le
E3.
Str
ess
Lev
el
Med
ium
*
Indi
vidu
al
Beam
F
atig
ue T
est
Res
ults
on
A
ccor
ex
Spec
imen
s C
onta
inin
g th
e Sa
me
Am
ount
of
Asp
halt
as
the
Con
trol
.
Ben
ding
In
itia
l T
otal
A
vera
ge
Str
ain
r~odul u
s (E
) In
put
Ene
rgy
Cyc
les
Inpu
t at
th
e at
th
e at
the
Sam
ple
Sam
ple
to
Str
ess,
20
0 cy
cl e
, 20
0 cy
cle,
20
0 cy
cle,
N
umbe
r H
t. (i
n)*
F
ail u
re
psi
in/i
n x
10-
4 ps
i in
-
1 b
ACC-
11
2.95
40
6,13
0 15
7.2
1.5
1,07
4,69
9 10
8,80
0
ACC
-12
2.98
19
0,87
0 16
0.2
2.4
679,
752
84,7
00
ACC
-13
2.99
48
0,82
0 15
7.2
2.5
639,
287
218,
300
I ------
Wid
th
of
beam
spe
cim
ens
was
3-
inch
es.
APPENDIX F
Results of Freeze-Thaw Pedestal Tests
on Individual Specimens
45
Table Fl. Freeze-ThaI" Pedestal Test Results.
I \
Bulk Air Void Complete Sample Height Specific Content, Cycles to
Type Number in. Gravity Percent Failure
AC-1 O. 747 1.776 26.4 2
Accorex AC-2 0.746 1.766 26.8 2
AC-3 O. 748 1.784 26.1 3
C-1 0.748 1.785 26.8 1
I Contro 1 C-2 O. 746 1.788 26.7 1
C-3 O. 750 1.788 26.7 1 1
46
- .... ----------------------------_._--------- ---
