Report No. COOT -D1D-R-93-22

INFLUENCE OF TESTING VARIABLES ON THE RESULTS FROM THE HAMBURG WHEEL-TRACKING DEVICE

Timothy Aschenbrener and Gray eLIrier

Colorado Department of Transportation

4201 East Arkansas Averue

Denver, Colorado 80222

Firal Report

December 7. 1993

Prepared in cooperation with the

U.s. Department of Transportation

Federal Highway Administration

The contents of this report reflect the views of

authors who are responsible for the facts and the

accuracy of the data presented herein. The

contents do not necessarily reflect the official

views of the Colorado Department of Transportation

or the Federal Highway Administration. This report

does not constitute a standard, specification, or

regulation.

i

,

Acknowledgements

The authors would like to express their gratitude to the many people who assisted in performing

this study. Kim Gilbert and Cindi Moya (COOT-Staff Materials) and Dave Price (COOT-Research)

performed testing on all the samples. Gayle King (Koch Materials) assisted with the development

of the experimental plan, and Mickey Hines (Koch Materials) provided technical review comments.

The COOT Research Panel provided many excellent comments and suggestions for the study;

it included Byron Lord and Kevin Stuart (FHWA-Turner Fairbank Highway Research Center), Ooyt

Bolling (FHWA-Region 8), Jerry Cloud (FHWA-Colorado Division), Denis Donnelly, Steve Horton,

Bob LaForce (COOT-Staff Materials), Ken Wood (COOT-Region 4 Materials), and Donna

Harmelink (COOT-Research).

Special thanks to the panel of Colorado Asphalt paving experts who provided numerous ideas

and suggestions which made the study more informational: Bud Brakey (BCE), Jim Fife (Western

Colorado Testing), Joe Proctor (Morton International), Scott Shuler (CAPA), and Eric West

(Western Mobile).

ii

Technical Report Documentation Page

I. Rep"'1 No. 2. Government Accession No. 3. Recipient's Catalog No.

CDOT-DTD-R-93-22 4. Till< ond Sublille S. Report Da le

Influence of Testing Variables on the Results from the December 1993

Hamburg Wheel-Tracking Device 6. Pedoruting Ol'ganizatioll Code

7. AUlhor(s) 8. Performing Organization Rpl.No.

Timothy Aschenbrener and Grav Currier CDOT-DTD-R-93-22 9. PCdlH'lOing ()J'gullizutiol1 Name and Address 10. Work Unit No. (TRAIS)

Colorado Department of Transportation

4201 E. Arkansas Ave. 11. ConlraCI 0" Gra"l No.

Denver Colorado 80222 12. Spr.nsol·ing Agency NUlnc and Address 13. Type of Rpl. and Period Cove,..,d

Colorado Departmen t of Transportation 4201 E. Arkansas Ave. 14. Sponsoring Agc"cy Code

Denver Colorado 80222 15. SupplementHI"), Notes

Prepared in Cooperation with the U.S. Department of Transportation Federal Highway Administration

16. Ah~tl'nct

The Hamburg wheel-tracking device can be used to predict the moisture susceptibility of a hot mix asphalt pavement. The test results are influenced by testing temperature, asphalt cement stL"fness, air void content, short-term aging, and the presence of lime. The variables are important to control in the laboratOlY environment to ensure repeatability. Additionally, these variables are also considered important to the moisture resistance of a pavement in the field.

J mplcmcnlntion:

17. Key Words 18. Distribution Statement

No Restrictions: This report is available to the public through the National Technical Info. Service. Springfield, VA 22161

19.5cc lII·ily Classir. (rcpOI'I) 20.Secndly Classif. (poge) 21. No. of Pages 22. P,ice

Unclassified Unclassified 116 iii

Table of Contents

1.0 INTRODUCTION . . ........... . ...... . ... • . .. •.. . . . . .... . .. . . . . . . . . 1

2.0 HAMBURG WHEEL·TRACKING DEVICE . . .. . . .. .....••... . .... . ..... .. . 2 2.1 Equipment and Procedures ................. . ..... .. ............ 2 2.2 Results and Specifications .. ......... . .. . .. . ... . . .. .... . .•. '. . . .. 2

3.0 MATERIAL DESCRIPTIONS . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . .. 5 3.1 Asphalt Cements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5 3.2 Aggregates . . . . . • . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . • . . . . • . . . 5 3.3 Hot Mix Asphalt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . • . .. 6

4.0 INFLUENCE OF TEST TEMPERATURE ON RESULTS . . . . . . . • . . . . . . . . . . . . .. 8 4.1 Experimental Grid .. . .. ... . ... . .. ........ ... ...•....... .. .• . .. 8 4.2 Results and Discussions ...... . .. .. ... . .. ..... .... . . ..... • .•... 8

4.2.1 Differential Test Temperature .. . .....•............. .. .• . .. 11 4.2.2 Absolute Test Temperature ... . ... ..• . . ....... . .......... 15

4.3 Recommendations.. .. ... ...... ...................... . .. . .. . .. 19

5.0 INFLUENCE OF AIR VOIDS ON RESULTS ..... . •.. . . ......• . . . . .. . .. . . . 21 5.1 Experimental Grid ..... ...... . . . ...• . ... ... . . .. .. .. . . .•.. .. ... 21 5.2 Results and Discussions .......... . . •.. .. .. . . . .. . ,. . .. . .. . . .. .. 21 5.3 Recommendations ..... . ..........• , ............ , ... . .... ..... 27

6.0 INFLUENCE OF SHORT-TERM AGING ON RESULTS . ..... ...... ..•.... ... 28 6.1 Experimental Grid ... . . . .. . ... .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 6.2 Results and Discussion ..••... . . . .. . ...... . .... ........... . .... 29 6.3 Recommendations . ... . . .. . ... .. .. .. . . ... ... . .... . . ... . . . .. . .. 29

7.0 INFLUENCE OF LIME MIXING ON RESULTS . .. . . . . .. . . .. .. .. .. . ... . . . . .. 31 7.1 Experimental Grid . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 7.2 Results and Discussions ... . . .. ... . .. . . ... . . .. .. . . .. ..... . . • . .. 32

8.0 CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . • . . . . . . . . . . .. 34

9.0 REFERENCES . .. . . . .. . .. . . .. ... . . .. .. .. .. . . . .• . .. . ...• . ... . .. . . . 35

Appendices

Appendix A. Hamburg Wheel-Tracking Results from the Test Temperature Study Appendix B. Hamburg Wheel-Tracking Results from the Influence of Air Void Study Appendix C. Hamburg Wheel-Tracking Results from the Short-Term Aging Study Appendix D. Hamburg Wheel-Tracking Results from the Ume Mixing Study

iv

List of Tables

Table 1. Asphalt Cement Properties . . ............ ..... , . . .... , . . . . . . . . . . . . . 5 Table 2. Optimum Asphalt Contents for the Mixes Used in this Study . . ...... .. . . .. ,. 7 Table 3. Experimental Grid for the Study to Determine the Influence of Testing

Temperature ... .......................... .. , , .... . .... .. , , .. __ . _ 9 Table 4. Results of the Test Temperature Study for Mix 1. . . . . . . . . . . . . . . . . . . . . . .. 10 Table 5. Results of the Test Temperature Study for Mix 2. . . . . . . • . . . . . . . . . . . . . . .. 10 Table 6. Results of the Test Temperature Study for Mix 3. . . . . . . . • . . . . . . . . . . . . . .. 10 Table 7. Results of the Test Temperature Study for Mix 4 .. . . , .... _ ' . ... _ . , . _ . . " 11 Table 8. Differential Test Temperature Between Various Asphalt Cements That Would

Provide Equal Stripping Inflection Points. . ...... ...................... ,. 12 Table 9. Test Temperature That Would Provide Equal Stripping Inflection Points for

Various Asphalt Cements. . ................ ...................... , . 16 Table 10. Recommended Testing Temperature for the Hamburg Wheel-Tracking

Device. . .... ............................................. . _ . .. 19 Table 11. Experimental Grid for the Study to Determine the Influence of Air Voids. . .. . . 21 Table 12. Results of Variable Air Voids for Mix 1. _ .. , _ .. . . . .... . . , . _ . . _ ... _ . . , 22 Table 13. Results of Variable Air Voids for Mix 2. . ...... ...... . . . . .. .. . . . . .. . . 22 Table 14. Results of Variable Air Voids for Mix 3. . . . .....•..... .. , ... . ...... . , 22 Table 15. Results of Variable Air Voids for Mix 4. .. . . . . .. .. . .• . ...• . . . .. .. .. . . 23 Table 16. Experimental Grid for the Study to Determine the Influence of Short-Term

Aging ....... .......................... ......... ............ • . . 28 Table 17. Stripping Inflection Point Versus Short-Term Aging Period . ............ ... 30 Table 18. Experimental Grid for the Study to Determine the Influence of Lime Mixing. ... 31 Table 19. Stripping Inflection Point Versus Method of Lime Addition . ....... .. , . . . . .. 32

v

List of Figures

Fig. 1. The Hamburg Wheel-Tracking Device. ...... ... . .. . • .......•.......... 3 Fig. 2. Close-up of Hamburg Wheel Tracking Device. . . . . . .. .. ... . . ... . . ..... . . 3 Fig. 3. Results from the Hamburg Wheel-Tracking Device. . . . . . . . . . . . . . . . . . . . . . .. 4 Fig. 4. Influence on Stripping Inflection Point for Various Temperatures and Asphalt

Cement Stiffnesses for Mix 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 13 Fig. 5. Influence on Stripping Inflection Point for Various Temperatures and Asphalt

Cement Stiffnesses for Mix 2. ... ......... . . . . . . . . . . . . . . . . . . . . . . . . . .. 13 Fig. 6. Influence on Stripping Inflection Point for Various Temperatures and Asphalt

Cement Stiffnesses for Mix 3. ......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Fig. 7. Influence on Stripping Inflection Point for Various Temperatures and Asphalt

Cement Stiffnesses for Mix 4. . .. ................................... , 14 Fig. 8. Temperatures Required to Obtain a Constant Stripping Inflection Point for Various

Asphalt Cement Stiffnesses for Mix 1. .... , .. , . , . . . . . . . . . . . . . . . . . . . . . .. 17 Fig. 9. Temperatures Required to Obtain a Constant Stripping Inflection Point for Various

Asphalt Cement Stiffnesses for Mix 2, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17 Fig. 10. Temperatures Required to Obtain a Constant Stripping Inflection Point for

Various Asphalt Cement Stiffnesses for Mix 3 .... ........ , ....... ,. , , . . . . 18 Fig. 11. Temperatures Required to obtain a Constant Stripping Inflection Point for Various

Asphalt Cement Stiffnesses for Mix 4. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 18 Fig. 12. Environmental Zones in Colorado. .......... ......... ... .. ........ .. 20 Fig. 13. Influence of Creep Slope with Changing Air Void Contents .. .. .. .. . ..... . .. 24 Fig. 14. Influence of Stripping Slope with Changing Air Void Contents . . . ... . . .. . .... 25 Fig. 15. Influence of Stripping Inflection Point with Changing Air Void Contents. . .... . . 26 Fig. 16. Influence on Stripping Inflection Point of Various Short-Term Aging Periods, . .. , 30

vi

Influence of Testing Variables on the Results

from the Hamburg Wheel-Tracking Device

Tim Aschenbrener and Gray Currier

1.0 INTRODUCTION

In September 1990, a group of individuals representing AASHTO, FHWA, NAPA, SHRP, AI, and

TRB participated in a 2-week tour of six European countries. Information on this tour has been

published in a "Report on the 1990 European Asphalt Study Tour" (1). Several areas for potential

improvement of hot mix asphalt (HMA) pavements were identified, including the use of

performance-related testing equipment used in several European countries. The Colorado

Department of Transportation (COOT) and the FHWA Turner-Fairbank Highway Research Center

(TFHRC) were selected to demonstrate this equipment.

The first priority of the demonstration was to verify the predictive capabilities of this equipment

by performing tests on mixtures of known field performance (2). The next step was to investigate

several testing variables that influence the results in order to better understand the test results

and their repeatability.

The purpose of this report is to identify the influence of four testing variables on the results from

the Hamburg wheel-tracking device. The variables investigated in this study are 1) testing

temperature and asphalt cement stiffness, 2) air voids of compacted samples, 3) short-term aging,

and 4) method of lime addition. It is important to understand how these variables influence the

test results so the laboratory procedure can be written to ensure repeatability. Further, these

variables are also considered important to the moisture resistance of a pavement in the field. Any

test that hopes to predict the moisture susceptibility of an HMA pavement should be sensitive to

these variables.

1

2.0 HAMBURG WHEEL-TRACKING DEVICE

2.1 Equipment and Procedures

The Hamburg wheel-tracking device is manufactured by Helmut-Wind Inc. of Hamburg, Germany

as shown in Figs. 1 and 2. A pair of samples are tested simultaneously. A sample is typically

260 mm (10.2 in.) wide, 320 mm (12.6 in.) long, and 40 mm (1.6 in.) deep. A sample's mass is

approximately 7.5 kg (16.5 Ibs.), and it is compacted to approximately 7% air voids. For this

study, samples were compacted with the linear kneading compactor. The samples are

submerged under water at 50°C (122°F), although the temperature can vary from 25°C to 70°C

(77'F to 158°F). A steel wheel, 47 mm (1.85 in.) wide, loads the samples with 705 N (158 Ibs.)

The wheel makes 50 passes over each sample per minute. The maximum velocity of the wheel

is 34 cm/sec (1.1 ftlsec) in the center of the sample. Each sample is loaded for 20,000 passes

or until 20 mm of deformation occurs. Approximately 6-.112 hours are required for a test.

2.2 Results and Specifications

The results from the Hamburg wheel-tracking device include the creep slope, stripping slope and

stripping inflection point as shown in Fig. 3. These results have been defined by Hines (3). The

creep slope relates to rulling from plastic flow. It is the inverse of the rate of deformation in the

linear region of the deformation curve, after post compaction effects have ended and before the

onset of stripping. The stripping slope is the inverse of the rate of deformation in the linear region

of the deformation curve, after stripping begins and until the end of the test. It is the number of

passes required to create a 1 mm impression from stripping. The stripping slope is related to the

severity of moisture damage. The stripping inflection point is the number of passes at the

intersection of the creep slope and the stripping slope. It is related to the resistance of the HMA

to moisture damage.

A sample is required by the City of Hamburg to have less than 4 mm rut depth after 20,000

passes. Testing by the CDOT has indicated this specification is very severe (2).

2

-

FIg. 1. The Hamtrurg Wheel-Tracking Device.

-- ..-J

FIg. 2. Ck>aIHJp of Hamburg Wheel Ttecldng DevIce.

3

o N •

c o

Fig. 3. Results from the Hamburg Wheel-Tracking Device.

4

3.0 MATERIAL DESCRIPTIONS

3.1 Asphalt Cements

It was desired to test asphalt cements with a variety of high temperature properties. Three neat

asphalt cements were used in this study and were provided by Frontier Refinery in Cheyenne,

Wyoming. The asphalt cements were AC-5, AC-10, and AC-20 (AASHTO M 226, Table 2).

Additionally, one polymer modified asphalt cement, AC-20P (AASHTO Task Force 31, Type I-D),

was provided by Koch Materials. The properties of the asphalt cements were measured with the

penetration at 25°C (AASHTO T 49), viscosity at 60°C (AASHTO T 202), ring and ball softening

point (AASHTO T 53), and the SHRP Dynamic Shear Rheometer (DSR) tests. Results are shown

in Table 1. For the DSR, the unaged asphalt cement would have a stiffness of 1.0 kPa at the

terrperature listed in Table 1. The possible high-temperature performance grade (PG) of the

asphalt cement as classified by SHRP is included.

Table 1. Asphalt Cement Properties.

Viscosity Penetration Ring & Ball DSR (OC) High @60°C @25°C Softening @ 1 kPa Temperature (poises) (dmm) Point (OC) Stiffness PG

AC-5 520 155 45.0 56.2 52

AC-10 1030 99 47.7 61.6 58

AC-20 1980 67 52.8 67.5 64

AC-20P 10280 74 62.2 77.4 70

3.2 Aggregates

Aggregates used for this study came from a variety of sources with a variety of performance

histories. The aggregates and combinations were selected to provide a variety of results, good

to poor, in the Hamburg wheel-tracking device. All mixtures used quarried aggregate. Two

5

different types of natural sands were added to help vary the performance of each mixture.

The aggregates for Mix 1 were entirely from a quarried source that has had a history of good

performance. The aggregates for Mix 2 were primarily from a different quarry with a good history

of performance. However, a poor quality natural sand was added. Although the natural sand is

non-plastic, it does have clay present.

The aggregate for Mix 3 was from a quarry with a mixed history of good and marginal

performance. A clean natural sand that has been associated with many HMA pavements that

have stripped was added. The natural sand does not adhere to asphalt cement very well. The

aggregate for Mix 4 was from a quarry with a history of poor performance. The poor quality

natural sand with clay used in Mix 2 was also added to Mix 4.

3.3 Hot Mix Asphalt

The optimum asphalt content for each of the mixtures was determined with the Texas gyratory

in general accordance with ASTM D 4013. The pre-gyration stress, end point stress and

consolidation stress used were 210, 690, and 17,240 kPa (30, 100, 2500 psi) , respectively.

These stresses simulate the loads applied to the HMA pavements by high levels of traffic in

Colorado.

The optimum asphalt content was determined for each HMA with the Frontier AC-20 and AC-5

using equi-viscous mixing and compaction temperatures. The optimum asphalt contents at 4%

air voids are shown in Table 2. There was not a significant difference in optimum asphalt content

with the different grades of asphalt cement. The asphalt contents of the mixtures used in this

study are also shown in Table 2.

All mixes were treated with an anti-stripping additive. When a liquid anti-stripping additive was

used, it was Pave Bond Special provided by Morton International. When hydrated lime was used,

it was provided by Chemstar Ume Company.

6

Table 2. Optimum Asphalt Contents for the Mixes Used in this Study.

~ Optimum Asphalt Content (%)

AC-20 AC-5 Used in This Study

Mix 1 5.1 5.1 5.1

Mix 2 5.1 5.1 5.1

Mix 3 5.2 5.1 5.2

Mix 4 5.3 5.1 5.3

7

4.0 INFLUENCE OF TEST TEMPERATURE ON RESULTS

The purpose of this study is to determine the influence of the testing temperature on results

obtained from the Hamburg wheel-tracking device.

4.1 Experimental Grid

The specified testing temperature in Hamburg is 50°C, and the asphalt cement used is typically

a 70 to 100 dmm penetration (AASHTO T 49 at 25°C). Since Colorado uses grades of asphalt

cement different from those used in the City of Hamburg, it was desired to determine the

influence of the testing temperature for different grades of asphalt cement.

The four grades of asphalt cement used in this study were the most commonly used grades in

Colorado: AC-5, AC-10, AC-20, and AC-20P. Since the quality of the mixture was thought to

have an influence on the results, four different HMAs were selected. Testing temperatures used

ranged from 35°C to 65°C. Each grade of asphalt cement was tested at three temperatures. The

temperatures were selected based on the performance of each mix in the Hamburg wheel­

tracking device. The full experimental grid is shown in Table 3. Some of the targeted testing

temperatures in Table 3 were adjusted based on the performance of each mix.

4.2 Results and Discussions

The samples were compacted on the linear kneading compactor to 7 ± 1.5% air voids. Replicate

samples were always tested. Results are plotted in Appendix A.

The stripping inflection point for each of the four mixes at the different combinations of

temperature and asphalt cement stiffness are shown in Tables 4 through 7. Plots of the stripping

inflection point versus test temperature for each of the mixes are shown in Figs. 4 through 7. In

all cases, the stripping inflection point increases as either the testing temperature decreases or

the asphalt cement stiffness increases.

8

Table 3. Experimental Grid for the Study to Determine the Influence of Testing Temperature.

4'5"

C

.Mtx t • Excellent X

Mix 2 • MaqJlnel X

Mix 3 • Mat"iIFla) X

MIx 4 - Ttlmble X -~-~

X - Replicate samples were tested.

NT - Not Tested

AC-2DP . . .

50" 55" 40"

C C C

X X X

X X X

X X X

X X X -

~- -

AV20 AO·tO

4ft 50" ~ . 4'fl" 45" 50· W

C C C C C C

X X X X X X

X X X X X NT

X X X X NT NT

X X X X X X L_

9

~- -

A()'5

40" 45"

C C

X X

X X

X X

X X

Table 4. Results of the Test Temperature Study for Mix 1.

~ Stripping Inflection Point (Passes)

40°C 45°C 50°C 55°C 60°C 65°C

AC-5 20,000 7,300 3,000 NT NT NT

AC-l0 NT 17,000 13,200 3,100 NT NT

AC-20 NT +20,000 +20,000 9,800 NT NT

AC-20P NT NT NT +20,000 +20,000 20,000

NT - Not Tested

Table 5. Results of the Test Temperature Study for Mix 2.

Stripping Inflection Point (Passes)

40°C 45°C 50°C 55°C 60°C

AC-5 18,200 6,300 NT NT NT

, AC-l0 NT +20,000 10,700 5,300 NT

AC-20 NT +20,000 12,500 7,500 NT

AC-20P NT NT +20,000 +20,000 17,800

NT - Not Tested

Table 6. Results of the Test Temperature Study for Mix 3.

~ Stripping Inflection Point (Passes)

35°C 40°C 45°C 50°C 55°C

AC-5 5,500 1,100 NT NT NT

AC-l0 10,000 3,200 NT NT NT

AC-20 NT 6,200 5,000 600 NT

AC-20P NT NT +20,000 8,100 5,600

NT - Not Tested

10

Table 7. Results of the Test Temperature Study for Mix 4.

~ Stripping Inflection Point (Passes)

35°C 40°C 45°C 50°C

AC-5 15,300 5,500 3,300 NT

AC-10 NT 17,300 11,900 4,600

AC-20 NT +20,000 14,900 8,800

AC-20P NT +20,000 +20,000 15,400

NT - Not Tested

4.2.1 Differential Test Temperature

When placing an HMA in the colder parts of Colorado, a soft asphalt cement is generally used.

This mix should be tested with a low temperature on the Hamburg wheel-tracking device, because

the highest field temperatures are usually not very high. When placing an HMA in the hottest

parts of Colorado, a stiff asphalt cement is generally used. When testing this mix in the Hamburg

wheel-tracking device a high temperature should be used to simulate the very high field

temperatures.

If 2llil. aggregate source is mixed with a soft or stiff asphalt cement for a cool or hot temperature

environment, respectively, then the stripping inflection point of both mixes should be the same.

In o!her words, as the grade of asphalt cement changes to accommodate the areas in Colorado

with high temperatures that range from cool to hot, the test temperature in the Hamburg wheel­

tracking device should be adjusted also. This is extremely important because the test results are

very sensitive to test temperature and asphalt cement stiffness.

The temperature differentials that would provide an equal stripping inflection point for the same

mix with different asphalt cement stiffnesses are shown in Table 8 as determined from Figs. 8

through 11. The location of the horizontal line drawn in Figs. 8 through 11 is based upon the use

of a~ asphalt cement typically used in Hamburg and tested at 50·C as explained in Section 4.2.2.

The temperature of the AC-1 0 was arbitrarily selected as "x".

11

As an example, consider Mix 4. The stripping inflection point of 7,000 passes was selected from

Fig. 11 based upon an AC-15 being tested at 50°C. To obtain a stripping inflection point of 7,000

passes for an AC-5, the test would have to be performed at 9°C lower than with an AC-10. To

obtain a stripping inflection point of 7,000 passes for an AC-20, the test would have to be

perfonmed at a temperature 4°C higher than with an AC-10. To obtain a stripping inflection point

of 7,000 passes for an AC-20P, the test would have to be performed at a temperature 10°C

higher than with an AC-10. These temperature differentials are shown in Table 8.

As expected, as the asphalt cement stiffness increased, the test temperature should increase to

result in the same stripping inflection point. Generally, each time the asphalt cement increases

one grade In stiffness, the test temperature should increase approximately SOC to result in the

same stripping Inflection pOint.

Table 8. Differential Test Temperature Between Various Asphalt Cements That Would

Provide Equal Stripping Inflection Points.

~ Temperature Differential (OC)

Mix 1 Mix 2 Mix 3 Mix 4 I Avg. II DSR I AC-5 x-4 x-6 x - 3.5 x-9 x-6 x-5.4

AC-10 x x x x x x

AC-20 x+6 x+3 x+6 x+4 x+5 x + 5.9

AC-20P x + (>20)' x + 15 x + 12 x + 10 x+(>14) x + 15.8

no: possible to determine exactly because the sample did not strip

It was extremely interesting to compare the temperature differential required to obtain equal

stripping inflection pOints with the Hamburg wheel-tracking device to the temperature differential

required to obtain a 1 kPa stiffness from the Dynamic Shear Rheometer (DSR). The comparison

is shown in Table 8. The differences in high temperature properties of each asphalt cement

measured by the Hamburg wheel-tracking device were almost identical to the differences

measured by the DSR.

12

.. • In In • ... -1: '0 ... ... " c c • oS! • ~ <i 0

.II E. :E r ... ... E /II

20,----,---~------ot_--e--"""'!'"--"'!'____, r---,

18 ······-·-j-··--··-····t ··-········-r-··· 18

! 14 ........ .j.... ............ _ ••• ..i. ........ _ ••••• _.1.............. ..~-.-..•... _._.L ................. i ................... L ....... .

12 .... j ........ ~::: ... .l .............. J-... -..... -.. ~ .. :.: ... : .... :.t: ................ L~._ ........ :..!. ....... . l . ~ 1

1: =~~·:~.::~.~I~~::::"~t· __ ~~~:J~ .. ::··~=:.! .. ~~~:~~~I~~:~~]:~~:~ r . I j r ", I I- I

6 ... - .... ~ .. ----... - ........ " ..... - ........ -+ ............ _ .. + ••.....•.... ··_j····· .. -···········f···_·· .. ··········f·········

: ! I !. I : : 4 ·····_·r······_···_···r··_··············t - .. _. ·········r·····:··_····· j···· .. ···········:·r················l .. ······

2 ---t···-········-·t---··--~-·-·-- .. ~.,~ ·_·_· __ ····-{·_·_-_··-.. ,1 ._-_._. _. ;i ._-

i, 1. .. , : : : o~-+--__ ~ ____ ±-__ ~~ __ -±~ __ ~ ____ ±--J ~ ~ ~ ~ ~ ~ ~

Test Tem!'erature (C)

-+-AC·' -­AC-l0

AC-20

-a­AC-20P

Fig. 4. Influence on Stripping Inflection Point for Various Temperatures and Asphalt

Cement Stiffnesses for Mix 1.

- . .. • co .. ~ .5 0 ... ... " c c • oS! • ~ <i 0

.II E. -.: r ... So :: /II

20~-'----'---~----~--~~---'----.--'r-----' !

18 ... - ... +. ......... -...... ...... -----, --....... -+-.... -... -.1------.. ·-·-··-···-···i····--! ! . ~ 1 l !

1S' -1_ 1 _. - : ~.. ~-' 1---.:~j~ .!--: . i · . . j~ ' . ... [' . ;· ~·:;.<:",: ·· · l .;. f .

14 --1-•..•• __ .•.•... .,.._.. ."" •...•.•. _........ ."'"_ ...... _ ........ ,-_._ •••.•... _, ........... _ ....••••••...•..

12 ········t·····-···-····:·t-·~··· ·-····i-······-.. -· .~ ." ........... -;--...... -........ L···············r······ 10 -·-t--·_·_···-·t·· .. ····· .. ··-t······--:·-:······f ..... ·····-i···· .. ····· .. ··_··;_· .. ·····_···_··f······_·

; . : : . 8 -'-,-.- .-1-:'-:--

;

18 ........ ..;.. .. _ ...... _ .... j-_ .. _ ...... _ .. 'I--•• _ •••••••••••• ~ ••• : ••••••• : •••• l··-···-··.·······~.-·· .......• ·-···i·····-··

: ±±r~±~l=r::=t o~~ ____ t-__ -ii~ __ ~i ____ ~: _~~i ____ ±--"

~ ~ ~ ~ ~ ~ ~

Test Temperature (e)

-+-AC-:\ -­AC-10

AC-20

AC-20P

Fig. 5. Influence on Stripping Inflection Point for Various Temperatures and Asphalt

Cement Stiffnesses for Mix 2.

13

.. .. .. .. .. ... -i .. ... .., c c • .9 • ~ 15 0

.l! E. S '" .5 II. II. ;: -rn

20-,----,----,---_--,..---~--~--~___, r---,

12

10 .. _ .. _.+ .. _ .. _._. __ . !

30 35

Test Temperature (Cl

-+­

AC-5 -­AC-10

AC-20

-e­AC-20P

Fig. 6. Influence on Stripping Inflection Point for Various Temperatures and Asphalt

Cement Stiffnesses for Mix 3.

-.. .. .. .. .. ... -l! '0 .. ... .., c c • .9 • ~ 15 0

.l! E. -.5

r II.

E-rn.

201-,---,,.---_---or------,------,---,..--___, r---, I !

; i 18

4 · __ ·_-_··t·· __ ······_·_-+···_········ - ...... i ........ _.:_ ........ l" ...................... ; .... _ ...... _._ ..... .j. ......... .

i : : I~' 1 i 1 ! r·

2~-4----4-----~----~----+-----+-~ 35 40 46 50 66 60

Tesl Temperature (el

-+-

AC-5 -­AC-10

AC-20

-e­AC-20P

Fig. 7. Influence on Stripping Inflection Point for Various Temperatures and Asphalt

Cement Stiffnesses for Mix 4.

14

4.2.2 Absolute Test Temperature

The Hamburg wheel-tracking device is commonly used by the City of Hamburg to approve and

accept HMA. Their typical asphalt cement has a penetration at 25°C of 70 to 100 dmm, which

is similar to a stiff AC-10 or soft AC-20 used in this study, approximately an AC-15. The high

temperature performance grade (PG) of the asphalt cement commonly used in Hamburg would

be approximately 64 to 70. Their specified testing temperature in the Hamburg wheel-tracking

device is 50°C.

A point was plotted at the 50°C test temperature and the stripping inflection point halfway between

the results from the AC-10 and AC-20, approximately an AC-15. This point represents the

"typical" test temperature and asphalt cement stiffness used in Hamburg. On Figs. 8 through 11,

a horizontal, dashed line representing a constant stripping inflection point was then drawn through

the point. As the grade of asphalt changes within each mix, the test temperature required to

obtain the same stripping inflection point is shown in Table 9.

For example, consider Mix 4 shown in Fig. 11. The horizontal line is drawn at the stripping

inflection point of 7,000 passes because 7,000 passes is at the intersection of the 50°C test

temperature and the test results for an AC-15 (halfway between an AC-10 and an AC-20). For

this particular mix, an AC-5 would have to be tested at 39°C, and AC-10 at 48°C, an AC-20 at

52°C, and an AC-20P at 58°C to have equal stripping inflection pOints. These temperatures are

shown in Table 9.

It was not possible to compare Mix 3 to the Hamburg test procedure since Mix 3 virtually

diSintegrated at temperatures lower than 50°C. The line representing the equal inflection point

shown in Fig. 10 is presented for information only.

15

Table 9. Test Temperature That Would Provide Equal Stripping Inflection Points for

Various Asphalt Cements.

~ Temperature (DC)

Mix 1 Mix .2 Mix 3 Mix 4 I Avg. I AC-5 42 43 NP 39 41

AC-10 46 49 NP 48 48

AC-20 52 52 NP 52 52

AC-20P NP 64 NP 58 61

NP - Not Possible

16

20

18

~ 16 .. 0 .. .. • 14 ... ~

E 12 '0 -• ... ."

C C • oS! • 10 ~

U 0

J! .c

:E t::. 8

r 8 ... ... ;: -III 4

2

0

,

.. _ .... -,1 ........ _ ........ _,:. . ............. ·t··········_····_-:;·· ...... --..... ,,:,;.-----.. ..,.-.. -.-:; ············· __ ···",1 .. · .. _·· , ._.-.-._._._ .... _._._.- ._._._ ..•.. -.-.-~.-.-.-.-... -.-.-.-.-.-.

=~=-#=jl=~#=-t=~c*: 35 40 60 56 66

TeSI Temperature (C)

-+­

AC-~ -AC-10

AC-20

AC-20P

Fig. 8. Temperatures Required to Obtain a Constant Stripping Inflection Point for Various

Asphalt Cement Stiffnesses for Mix 1.

20

18

~ 18 .. .. .. .. " 14 e:. ! .. 12 .... ." C C • .!! • 10

~

U 0

.!! E. :E 8

III .5 a ... ... ;: -III 4

2

0

! r'" . !', , j~ .... _--_ ..... -:. ........ . 1 . r • .; •••••••• _.~; •• __ •••• _.:",:::_ •••••••• _'-... _._.,. ...... _ .......... : ................... !,.. i'

. l', : '~. _. r ' ----·-··t·········-····-·~··· ·~;·····-···1······

i -... -.. ~ ........... --.. -+--j ~

._ ... .l. .... _ ... _--..i.---. ..... _._._._--._.-. . I

-·-·····!·········-·-···r·~·······i·······r·········--'-rr" i"-"-'" ·:····_· __ ·······J-·······-········i--··j

:::::::I:~:-::-:::·::::r::·:::l:::·T:::::::::·::·lH::·~:~~::~~~~:~:::::~~r:::::::::::~I:::r : I I : I I

36 40 46 56

Test Temperature (C)

-+-

AC-~ -AC-10

----­AC-20

--€­

AC-20P

Flg.9. Temperatures Required to Obtain a Constant Stripping Inflection Point for Various

Asphalt Cement Stlffnesses for Mix 2.

17

20

18

.. 18 .. '" '" II 14 .. -E

12 Q .. .. ... C c

g

i • 10 ~ •

.! E. ~ 8 .E

'" c Q. 6 .!!-:: ., 4

2

0

...... .1. ................ :---.............. + ............... t .................. ; ................... , ................... , ........ .

~~~=~--~:-~~~~~~~--!=t: ··-····~··-·---··-··-·-··-t--·····-···· .. -T··--·--·---- ..... ~".: .......... ···· .. ·:···················1············· .. ··..!.····· .. ·

: :

=:~=~-:t--:~~:=~~- ~=+~~+~~F .l··· .. ···········_·l·· .. ···············t·········

i ! . . .

-·--····t·-···;··········--·~!··:-·~~·~!···T:::;.::~~·t·:~:-~:::;~+1·~:::·~::~::·~:·~:::·~1·~:·~:·

· .. ·····t············· .. ···tt··········~ .. t··········_ .. ·+·-:······· .. ·H··· .. ·········+··· .. ············1········· r;; I i

30 40 46 50 66 60

Tes) Temperalure (Cl

AC·:! -AC·l0 --AC·20

-e­AC·20P

Fig. 10. Temperatures Required to Obtain a Constant Stripping Inflection Point for Various

Asphalt Cement Stlffnesses for Mix 3.

.. .. .. .. II .. -E Q -• .. ... c c • i • ~ • .! E. :E 2' Q.

E .,

20~~----~.-----~--~~----~------~-, r----~

18

18

14

12

10

8

8

4

2

-....... 1 ........ _ .. _ ..... L .......... . . ! , ,

j j\

: . : " . 40 46 50 66

Tesl Temperalure (el 80

AC·~ -AC·l0 --AC·20

-e­AC·20P

Fig. 11. Temperatures Required to obtain a Constant Stripping Inflection Point for Various

Asphalt Cement Stiffnesses for Mix 4.

18

4.3 Recommendations

The test temperature should relate to the temperature the pavement will experience. The

environmental zones within Colorado are defined by county in Fig. 12. Although the

environmental zones are not constant within each county, it is shown for approximate information.

The four high temperature categories in Colorado are shown in Table 10. SHRP has developed

high temperature gradings for asphalt cements based on the highest pavement temperature at

a c9rtain depth. SHRP's corresponding performance grade (PG) recommended in each high

temperature category is listed in Table 10. The asphalt cements selected for testing in this

experiment are approximately the asphalt cements that would be used in each high temperature

category.

The recommended testing temperatures for the Hamburg wheel-tracking device should be

selected based on the high temperature environment the pavement will experience as shown in

Table 10. These testing temperatures should provide equal stripping inflection pOints for a mix

as the asphalt cement grade is changed. These temperatures would likely correspond with the

City of Hamburg test procedure.

Table 10. Recommended Testing Temperature for the Hamburg Wheel-Tracking Device.

High Approximate High Temp. Asphalt Recommended Temperature Highest Performance Cement Grade Test Temp.

Category Average Grade (PG) Meeting the for the 7-Day Air °C High Temp. Hamburg Device

Temperature PG

Very Cool <27°C 46 35°C

Cool 27 to 31°C 52 AC-5 40°C

Moderate 32 to 36°C 58 AC-l0 45°C

Hot >36°C 64 AC-20 50°C

Very Hot • 70 AC-20P 55°C

• No pavements in Colorado are at this temperature. A binder with this grade may be appropriate for locations with very heavy and slow moving traffic.

19

!! ~ ... !'> m :J So .. 0 :J 3 ID :J !if

S' :J ID en :J

g 0" iii Do

~ I\) 0

Zone

~6; .... :::;(: 1 : _2: : ·3:

[:~:;:;::]~:

"',~I.,

.... ~a

L1LlL I RONMENTAL Z 0 N E S

Elevati on over 8500', Cool, Wet, High Frost Penetration Elevation 6500 to 8500', Cool, Wet, High Frost Penetration Elevation 6500 to 8500', Cool, Very Dry, High Frost Penetration Elevation less than 8500', Warm, Dry, Low Frost Penetration Blevation less than 6500', Very Warm, Very Dry, Very Low Frost Pe netrati on

c...1" .. W

.....

, .. ... ,.;,., ..

----------Not e : This map does no t reflect changes made to a small number of highway

segments at the direction of the Engineering Di s trict offices .

5.0 INFLUENCE OF AIR VOIDS ON RESULTS

The purpose of this study was to determine the influence of the air void content of the sample on

the results from the Hamburg wheel-tracking device.

5.1 Experimental Grid

The experimental grid for this experiment is shown in Table 11. Four different air void contents

were targeted: 4%. 6%. 8%, and 10%. These air void contents represent the full range of air void

contents inHMA pavements just after construction in Colorado. Four mixtures with different

performance histories were used. One testing temperature. 50°C. and one grade of asphalt

cement. AC-20, were used for all mixtures in this experiment.

Table 11. Experimental Grid for the Study to Determine the Influence of Air Voids.

~ Aj(V~

4% &'k So;. 10%

Mix 1 X X X X

Mix 2 X X X X

Mix 3 X X X X

IWx 4 X X X X

X - Replicate samples were tested. All samples were mixed with AC-20 and tested at 50°C.

5.2 Results and Discussions

The mixes used for this portion of the study. influence of air voids, were not treated with liquid

anti-stripping additives. The liquid anti-stripping additive was inadvertently left out.

Results from each mix are summarized in Tables .12 through 15. Results from each replicate

sample are plotted in Appendix B. When testing replicate samples, the results from the two

samples were often similar. However in some cases, the results were quite different. It is very

important to test replicate samples.

21

Table 12. Results of Variable Air Voids for Mix 1.

Air Temperature = 50°C Voids (%) Creep Slope Strip Slope Strip Inflec.

(passes/mm) (passes/mm) (passes)

4.2 11,100 900 8200

4.7 7500 800 7500

7.8 5400 1200 14700

8.7 9700 1100 7800

Table 13. Results of Variable Air Voids for Mix 2.

Air Temperature = 50°C Voids (%) Creep Slope Strip Slope Strip Inflec.

(passes/mm) (passes/mm) (passes)

3.5 2600 900 5000

5.0 3700 700 4900

7.1 4200 1200 5800

8.7 2000 400 5500

Table 14. Results of Variable Air Voids for Mix 3.

Air Temperature = 50°C Voids (%) Creep Slope Strip Slope Strip Inflec.

(passes/mm) (passes/mm) (passes)

5.5 1700 500 3200

8.1 1700 500 2100

9.6 700 400 400

10.5 1300 300 2500

22

Table 15. Results of Variable Air Voids for Mix 4.

Air Temperature = 50·C Voids (%) Creep Slope Strip Slope Strip Inflec.

(passes/mm) (passes/mm) (passes)

5.7 4600 1000 5300

7.5 3800 900 5500

9.3 3800 500 8100

10.4 2400 370 7000

The influence of the changing air void properties on the creep slope for the four mixes is shown

in Fig. 13. For Mix 2, 3, and 4, the creep slope remains essentially constant as the air voids

change. For Mix 1, the creep slope is large at low and high air voids and smaller at intermediate

air void contents.

The influence of the changing air void properties on the stripping slope for the four mixes is

shown in Fig. 14. The stripping slope may tend to decrease as air voids increase based on the

perf.Jrmance of Mixes 3 and 4.

The influence of the changing air void properties on the stripping inflection pointfor the four mixes

is shown in Fig. 15. The stripping inflection point remains constant as air voids change for Mix

2, Mix 3 and Mix 4. The inflection point remains constant for Mix 1 with the exception of the

samples between 7 and 8% air voids.

It was hypothesized that higher air voids should produce a lower stripping inflection point on the

Hamburg wheel-tracking device. In this particular study, the hypotheSiS was not proved.

However, past testing in the CDOT laboratory using the Hamburg wheel-tracking device has

indicated that air voids greater than 10% produce significantly lower stripping inflection points than

samples compacted to 6 or 7% air voids.

23

-E E Ii

CD I/) I/) CCI

0.. -CD Q. 0

(j) Q. CD CD .. 0

~

II

"2 II ~ 0

~ -

12~----'-----'------'-----'-----'-----;-----;----1 ~---'

I ! .

1 0 -·-----·-··-l···-·· ·---·· · ·····1-·-· ·-· ··-·-·-·-·-t-··-·······-·-·-·~--·-"'-'-r--" '- '-'-"r~--"'-"" -'T'--"---"'-"-

. 1

8---4----i-----"------r--t ----i------1.;··· ·······-············· i j

6 ................. -_ ....... i ............... _ ........ ; .......... _ ...... _ ...... .(. ..................... . t j [

, , ~

, , , .. . ... -..... -.... -~ .... -... -.-.. - .--j ... -...... -.. -.... -_··t-·····_·_·······_·-4 .. -.... " .. _ ............ ~ ............. _ ...... _L._ ............ -........ .

i . i

!

2 --.... - ... -.. --L-.---.. --i-.-.. -.. -.~---· --··1-·_······ __ ···+-·_-_·

j

I i ! , .

--;-.-.--.-.--.~ .. ----.. -.. -.-i !

0+----4----~----r----+----+_--~----~~~ 3.0 4.0 5.0 6.0 7.0 S.O 9.0 10.0 11.0

Air Voids (%)

--+--­Mix 1

Mix2 -Mix3 -a­

Mix4

Rg.13. Influence of Creep Slope with Changing Air Void Contents.

24

-E E (i) CI) I/) I/) ca

0.. -CI) c.. 0

en C) c: "a c..

"i: -0

1200 ,

1100 ! j. .

··············· __ ·········f·······················:···i.~ ........................... l.; .. :............. . ................... .......... ! .............. . , --f----,-------! ! .i,

i 1000

900 1 ,

......... i ... --·----······ ........... i ...... __ ·.· .. ··_··· ...... j •• ___ ••••••••••••••• •••••• [ I : 1

· .. ·····---·--·-·r·-·····----····r· .. -····-· ;

............. _ .... .1 .......... .

I 800

700

600

······ .. ·····-···········r·· ........ i :···············-········-t····-··-····· .. ······j-····· .... -........ -.-.

----r------- i----l----i- -f---r---·············,············t························-r·-··_··········--1-··-······· .. ············"1"·····-····· .. ··········r····· ............ ·-:-··········-·····-······r··-················--

500 ·------··-···-·t ... ··-··-·----·-~····-- ·--··-1-····_·· __ · __ ·-·· ! :

~ , 400 ···················· .. ·r············-···········:···················-··+···············-········r··················· ··i··············-·

300+-----+' -----+-----+-----+· -----+-----r-----r~~~ 3.0 4.0 S.O 6.0 7.0 8.0 9.0 10.0 11.0

Air Voids (%)

Fig. 14. Influence of Stripping Slope with Changing Air Void Contents.

25

-+­Mix 1

Mix2 ~

Mix3 -e­Mix4

0;-CD /I) /I) lIS

0.. --c '0 0.. C 0

:s CD

;:: c -0) c '0. 0-';: -U)

c;; "0 C

" til :::I 0 ..c I--

16.---.,.----,; ---;-----;---,---,..----y-------, ' __ -----, ! :

ii . Mix 1 14 -·--············-·+-·-···-·--·-·-I--····- .. ·--t--·-···----· .. t··--··· .-- r-·- ····-···---j--·····---··-;-·-·-·-·--·

i · I j . . . iii ......... t",.I ....... . ..... . . .. _ . ... _

12 .................. ····r··········-········T·······················r····· ...... - ·······r ······-··-··········r ·······--···-··T·····-·-····· ,

10

8 .......................... ,....... . ...... -.. ·············T·····-············-···

6

I

4 ··-·-··-······ ·····:·····-···-·-· ··-~·r·····-········· ····r··-········-·· ·-·-t······-········--·-t·····-··-··········,-······················r·········-······-·-: ': i :

2 .. - .. --.----+.---... -.--.-.-,----- ..... -.... ;----.. --..... +----.-.- ...... -.--+-... ----.. -.. - i······ , ~

o+---~---~!~--~----+---_+---~-~~--~ 3.0 4.0 5.0 6;0 7.0 8.0 9.0 10.0 11.0

Air Voids (%)

Mix2 -Mix3

-a­Mix4

Fig, 15. Influence of Stripping Inflection Point with Changing Air Void Contents.

26

There could be two potential explanations. First, there were not many samples compacted higher

than 9% air voids. The reduction In the stripping inflection point may not occur until the air voids

are slightly higher.

Second, the material tested in this portion of the study had no anti-stripping treatment. As a

result the stripping inflection points were all very low. The fact that all materials had very low

stripping inflection pOints at normally accepted air void contents could have been the reason the

stripping inflection point did not decrease substantially at higher air void contents. Engineering

properties (air voids, voids in the mineral aggregate, voids filled with asphalt) are important to

good pavement perfonmance. Chemical properties (asphalt cement chemistry, asphalt-aggregate

interaction) are also important to good pavement performance. Stripping can likely result from

deficient engineering properties, chemical properties, or engineering and chemical properties. A

future hypothesis could be: If chemical properties are deficient, the pavement will exhibit moisture

damage regardless of engineering properties.

5.3 Recommendations

Based on testing samples at a variety of air void contents, it is recommended to test samples at

6 ± 1 % air voids. In general, the stripping inflection point is not significantly influenced by the air

void content in this range. By using a tight control on the air voids, repeatability of the test results

.should be better than if no control were maintained on air voids. It is very important to test

replicate samples.

27

6.0 INFLUENCE OF SHORT-TERM AGING ON RESULTS The purpose of this experiment is to determine the influence of short-term aging on the results

obtained from the Hamburg wheel-tracking device.

6.1 Experimental Grid

The experimental grid for this experiment is shown in Table 16. Samples were short-term aged

at 143°C (290°F) for four different times: 0, 2, 4, and 6 hours. Four mixtures with different

performance histories were used. One testing temperature, 45°C, and one grade of asphalt

cement, AC-1 0, were used for all mixtures in this experiment. All mixtures in this study contained

hydrated lime.

Table 16. Experimental Grid for the Study to Determine the Influence of Short-Term Aging.

I o 12) 4 It I Mfli: 1 x x x x Mjx2 x x x x Mix 9 x x x x

x x x x

x - Replicate samples were tested. All samples were mixed with AC-10 and tested at 45°C.

The loose mix for each sample was placed in an open, rectangular baking pan, of dimensions 27

cm x 30 cm x 6 cm high. The samples weighed between 7.2 and 7.4 kg. Each sample's surface

was leveled, and each sample occupied a height of approximately 5 cm within its pan. As a

result of the open, low-profile pans, a relatively large surface area of each sample was exposed

to the 143°C forced-draft air flow. After each sample had been in the oven precisely the targeted

time, it was compacted. For those samples short-term aged zero hours, the mix was placed in

the ovens in covered pans for about fifteen minutes, just long enough to return to 143°C before

compaction. All samples were compacted in the linear kneading compactor to a targeted air void

content of 6 ± 1%.

28

6.2 Results and Discussion

The stripping inflection points after the different short-term aging times are shown in Table 17.

Plots of the stripping inflection point versus short-term aging time are shown in Fig. 16. Results

are plotted in Appendix C. In most cases, the stripping inflection pOint increased as the period

of short-term aging increased. All samples aged for 8 hours had stripping inflection pOints greater

than 20,000 passes. It was not possible to determine the precise stripping inflection point,

because the test ended at 20,000 passes.

II was noted that the mixes which had been short-term aged for eight hours had a somewhat

burnt odor when they were removed from the ovens, and they were noticeably harder to remove

from the pans for compaction . The eight hour exposure to forced-draft hot air physically and

chemically changed the binder, giving it the behavior of a stiffer asphalt cement. Although the

mix had improved anti-stripping qualities, it may have a greater likelihood of thermal cracking.

An unanticipated outcome of the laboratory short-term aging process was noted during the course

of the experiment. It was observed that in every case, as the short-term aging period increased,

the air void content decreased. For each doubling of the short-term aging period, air voids

dropped by about 0.4%. The cause is not clear. It might be a result of the increased absorption

of the binder by the aggregate during prolonged periods in the ovens, but further investigation is

needed. The improved stripping inflection point of the short-term aged mixes may be partly

attributable to the decrease in the mixes' air void content.

6.3 Recommendations

The duration of laboratory short-term aging was shown to be an important determinant of the

behavior of HMA tested in the Hamburg wheel-tracking device. It is recommended to bring the

sample to compaction temperature in a covered container for 4 hours. A covered container will

minimize the variability in results created by various sizes of containers and various models of

ovens that have different forced-air characteristics. For a sample that has just been mixed, a

conservative time to heat the sample to compaction temperature is typically 2 hours. Therefore,

most samples, including cooled field samples, should reach compaction temperature by 4 hours.

Tight control on this procedure will be necessary to obtain repeatable results.

29

Table 17. Stripping Inflection Point Versus Short·Term Aging Period.

Stripping Inflection Point (Passes)

I Short·Term Aging Period (Hours)

I Mix 0 I 2 I 4 I 8

1 3,000 12,600 13,900 >20,000

2 8,900 14,500 10,400 >20,000

3 2,300 4,200 7,200 >20,000

4 5,300 9,700 13,400 >20,000

20.0 . > 20.000 Pa.... J

-~/

18.0

~ 18.0 .. 0 • .. 14.0 .. !!:. 1: .. '0 1! 12.0 .. • • .c ~

0 10.0 O. t:. J! .. -.E 8.0

~ V --.~ Mix 1

~ ~/ 'l --Mix 2

/ A --;/ ;..-- v / ---./

I .", / V Mix3

/ / -e-

v ." IlL / .. Mix 4 . . - .. . •.. - -

... , . . • < • ..

... 'S '" 8.0

4 .0

A ./" vI / V V

2.0 o 2 3 4 5 8 7 8

Short-Term· Aging Period (Hrs)

Fig. 16. Influence on Stripping Inflection Point of Various Short·Term Aging Periods.

30

7.0 INFLUENCE OF LIME MIXING ON RESULTS

The purpose of this study is to determine the influence of the method of lime addition on results

obtained from the Hamburg wheel-tracking device.

7.1 Experimental Grid

Hydrated lime is used as an anti-stripping additive for approximately 90% of the HMA placed in

Colorado. Specifications require the contractor to use an approved pugmill to mix the aggregate

and lime. The moisture required during mixing is 3% above the saturated surface dry moisture

content of the aggregate. Despite the specification, there is a wide variety of mixing methods and

moisture contents used throughout the state. This experiment was designed to determine if the

specification should be enforced more strictly than it presently" is. The experimental grid is shown

in Table 18.

Table 18. Experimental Grid for the Study to Determine the Influence of Lime Mixing.

M&1l!\od of Lime Addition

No Lime t% Lime t% Lima 1'%Ume -t% Lim$ No Mol$tur~ NQ MoisttIre .2%MoiSlure 4% MolstufE; 4% Moi$lt.ire No 'Mellow" No "Mellow" NU "Mellow" No "Mel1UW" a-Day 'MeDaw'

'Milt 1 X x x x x Mill 2 x x x x x MillS x x x x X

Mix 4 X X X X X

x - Replicate samples were tested. All samples were mixed with AC-10 and tested at 45°C.

One set of samples from each mix contained no added lime. All the other samples had 1%

hydrated lime. Hydrated lime was added using three different levels of moisture: no water, 2%

water, and 4% water. The presence of water dissolved the hydrated lime and produced uniformly

coated aggregates. After water was added, the aggregates were immediately dried and mixed

31

with asphalt cement. For the final set of samples the dry aggregate, lime and 4% water were

mixed and then placed in a sealed plastic bucket for 72 hours. At the end of this "mellowing"

period, the aggregate was dried, then mixed with asphalt cement. Samples were short-term aged

for 4 hours.

7.2 Results and Discussions

The stripping inflection points for the different tests are shown in Table 19. Results are plotted

in Appendix D. In all cases, the stripping inflection point increased after lime was added. Even

the addition of dry lime alone improved the mix performance. In some instances a stripping

inflection point developed when lime was present, but the stripping slope was not very steep. In

these cases the deformation at 20,000 passes was less than 10 mm. That could be considered

an acceptable test result (2). When no lime was added, the stripping inflection points were very

low and the stripping slopes were very steep, indicating an unacceptable material.

Table 19. Stripping Inflection Point Versus Method of Lime Addition.

Method of Lime Addition

No Lime 1% Lime 1% Lime 1% Lime 1% Lime No Moisture No Moisture 2% Moisture 4% Moisture 4% Moisture No "Mellow" No "Mellow' No "Mellow' No "Mellow" 3-Day 'Mellow"

Mix 1 5,100 >20,000' 12,200' 13,600' 12,900'

Mix 2 7,900 10,800 10,800 12,500' >20,000'

Mix 3 2,600 17,700' 6,100 >20,000' >20,000'

Mix 4 7,400 10,000' 18,300' >20,000' 11,900'

. Passing test using the 10 mm specification

It Is not clear how the method of lime addition influences the HMAs ability to resist moisture

damage. However, the presence of hydrated lime helped the moisture resistance of all the mixes

tested. Adding 2% to 4% water to the limed aggregate improved the performance of the mix

compared to the addition of lime and no water, but the improvement was only slight and probably

not significant. It was difficult to quantify the improvement of the mixes by the addition of various

32

amounts of water. What is significant is that the addition of lime improves the anti-stripping

performance of all the mixes tested, and that lime mixed with an aggregate moistened to 4%

seemed to work well.

The use of the 3-day mellowing period did not substantially improve the performance. Two of the

mixes (Mixes 2 and 4) contained aggregates that were non-plastic but did have clay present.

Although the mellowing improved the performance of Mix 2 to meet the City of Hamburg

specification, the same improvement was not observed in Mix 4.

7.3 Recommendations

Adding 1 % lime to aggregate improved the anti-stripping performance of HMA. For uniformity of

laboratory procedures, 4% water should be added to the aggregate. Once the aggregate, lime,

and moisture are mixed, the laboratory sample should not be "mellowed". If the standard practice

of a contractor is to stockpile aggregate treated with lime to "mellow", then the laboratory

procedure should include "mellowing".

33

8.0 CONCLUSIONS

The variables investigated in this study were 1) testing temperature and asphalt cement stiffness,

2) air voids of compacted samples, 3) short-term aging, and 4) lime mixing. These variables can

influence the test results so the laboratory procedure should be written to include tight control on

these variables to ensure repeatability. Additionally, these variables are also considered

important to the moisture resistance of a pavement in the field. Although it is not clear how the

method of lime addition influences the HMAs ability to resist moisture damage, it is known that

the presence of lime helps the resistance of an HMA to moisture damage. Any test that hopes

to predict the moisture susceptibility of an HMA pavement should be sensitive to these variables.

1) The test temperature and high-temperature stiffness of the asphalt cement have significant

effects on the results from the Hamburg wheel-tracking device. It is important to select the

asphalt cement for an HMA based upon the environmental conditions the pavement will

experience. As the environmental conditions change from one part of the state to the next, it Is

important to select the appropriate asphalt cement stiffness. As these environmental conditions

change, it is equally important to adjust the test temperature of the Hamburg wheel-tracking

device.

SHRP has recommended the high-temperature grading of asphalt cements be based on an equal

stiffness measured by the DSR. The differences in high temperatures to obtain the same

stiffness measured by the DSR of the asphalt cements used in this study were about 6°C. The

Hamburg wheel-tracking device provides equal stripping inflection points for each grade of asphalt

cement when the test temperature is adjusted about 6°C for each grade. The similarity of the

temperature differentials of each grade of asphalt cement measured by the DSR and Hamburg

wheel-tracking device were amazingly similar. The testing temperatures for the Hamburg wheel­

tracking device should be selected based upon the high-temperature environment. The

reccmmended test temperatures are shown in Table 10.

34

2) Based on testing samples at a variety of air void contents, it is recommended to test samples

at 6 ± 1 % air voids. In general, the stripping inflection point is not significantly influenced by the

air 'foid content in this range. By using a tight control on the air voids, repeatability of the test

results should be better than if no control were maintained on air voids.

3) The duration of laboratory short-term aging was shown to be an important determinant of the

behavior of HMA tested in the Hamburg wheel-tracking device. It is recommended to short-term

age . laboratory mixed and field produced samples for 4 hours in a closed container prior to

compaction. Tight control on this variable will be necessary to obtain repeatable results.

4) Adding 1% lime to aggregate improved the anti-stripping performance of HMA. For uniformity

of laboratory procedures and to facilitate mixing, a standard process should be followed. Dry

aggregate and dry lime should be mixed together; 4% water should then be added, and the

sample should be mixed again.

9.0 REFERENCES

1. Report on the 1990 European Asphalt Study Tour (June 1991), American Assoc;iation of State Highway and Transportation Officials, Washington, D.C., 115+ pages.

2. Aschenbrener, Tim, R.L. Terrel, and RA Zamora (1994), "Comparison of the Hamburg Wheel­Tracking Device and the Environmental Conditioning System to Pavements of Known Stripping Performance," Colorado Department of Transportation, CDOT­DTD-R-94-1.

3. Hines, Mickey (1991), "The Hamburg Wheel-Tracking Device," Proceedings of the Twenty­Eighth Paving and Transportation Conference, Civil Engineering Department, The University of New Mexico, Albuquerque, New Mexico.

35

Appendix A

Hamburg Wheel-Tracking Results from the Test Temperature Study

0

-2

-4

E E -6

<: .Il -8 .. " ~

-10 D-E

E -12

" E .~ -14 ::;;

-16

-18

-20 0 2 4 6

Mix 1, AC·20P Temperature = 55 C

8

.

10 12

~o . . o~ -P-asses (Tho,,;'n~.)

, .

Profiles Temperature = 55 C

14 18 · 18

°l~· · .~-.--... -~- ~~Q ..... . '~ '-•• ,~ •. ' :iIIJ!Ij -2 .. -4+---+---+---r-~~-1~-+---+---r---r--~ e .. ..

S -6+---+---+---r-~---1---+~-+---r---r--~ c . .

S · -8+---+---+-~4---~--~~1---~--4---~--~ CD co ~ ... -10+---t--t---t--+--+--1--"'"i--t---+--~ ~ ..

.. -12+---+-+-4--4--+-+-+-~-'--+---I en I!

~ -14+--+--+---+---+---+----+---+---+---+---1

.

-16+--+--+---+---+---+---+---+---+---+---1

-18+---t--t---t--+-'-+---1--"'"if--t---+--~

-20+---1---I---+---I----+---+,---iL--f.---I----j o 25 :50 75 100 12:5 150 175 200 225 250

Wheel Position ·

Al

20

1000 Pass ••

E 5-c

.11 m m f Q.

1: E " E

.~

:::;

E S. j .. .. .. ~ ... ! • '" • ~ ~

0

-2

-4

-6

-8

-1 0

-1 2

-1 4

-1 6

-1 8

-20 o

0

-2

-4

'6

-8

-10

-12

-14

-16

-18

-20 0

r-

2 4

-~.

"<: ........... ~ ..

25 ~O

.

, .....

6

Mix 1, AC-20P Temperature = 60 C

8

. .

10 12

No: of PJllSe9 (Ttio~.~nd • .i

Profile.· Tel1lperature . = floe

.

.--- .... :-.;-. - ." Y-";'- .. -.... -..... -' ... ".~ .... " ......... ;, .. f" .• .

.. .

. ..

75 100 12~ 1~ 175 Wheel PositiOn-

A2

.

14 16 18 20

.

~ 1000P.ss .. ...... '......, . ... _--_.

1ooooP ...... . ..... ........

11000" •• ""

2oo00P .....

. .

200 225 250

0

-2

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c .l! -a .. .. .. ~ -10 ... ! .. -12

'" I! -14 .. > ..:

-16

-18

-20 0 25

4

.......

Mix 1, AC-20P Temperature = 65 C

II lQ 12 14 18 . 18 2Q

·1Ijo.ofPa .... ,{tbou •• ri~.) .

. ' " .: ' " '.

Profiles Temperature = 65 C

~

"_ .•• h.. .

75 100 125 150 175 200 22~ 250 Wheel PosHion .-

A3

1SOOO 'as ...

0

·2

·4

E £ ·6

c .11 .. -8 .. ~

·10 0-

E E ·12 :J

.§ ·14 ~

::Ii ·18

-18

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0

-2

-4 ~

E E -6 ~

j -8 .. .. . " ~ -10 Do

S " -12

'" .. ~ -14 ~

-16

-18

-20 0

2 4

25

Mix 1, AC·20 Temperature _ 45 C

8 10 12 14 16 18 20

No. of Palles (Thou.and.)

Profiles remperaiure = 45 C

75 100 125 150 175 200 225 250 Wheel PasHion

A4

1000 'uses

10000 Puses

15000 Puns

i

0

·2

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0

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j -8 .. .. ! -1 0 II.

! .. ... ,12

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·1 6

-1 8

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"------- ---

2 4

Mix I, AC·20 Temperature = 55C

~

~ "\

\ \

..

8 .10 .' 12

No. of p..a ... ·· (ThQu •• nda)

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\ \

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14

~ •... "...... ........... ..•...... . ..•. ~. . ............ ,.. ...,~ .... -:;. . . .. .............. ".

.... - iI

16 18 · 20.

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tOOOO Pnses

2~ ~ 7~ 100 12~ 1~ 175 200 225 2~

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0

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8 10 12

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14 16

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6

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,

I

4 6 10 12 14 16 18

"'.-0 ... " ...... "

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Profiles Temperature = 55 C

" .-.,.~. .. ............................ ;.

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AS

20

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.

2 4

25

8

Mix 1, AC-5 Temperature = 40 C

8 10 12

No_ 01 Passes (Thou •• nd.)

Profiles Temperatu", = 40 C

l

14

..... \ .. ~ .1 ~- ...,

16

75 100 125 150 175 200 225 250 Wheel Position

A9

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Mix 1, AC·5 Temperature = 45 C

'"

8

1\ \

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Proflljls· Temperature = 45 C

'. ~ .

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.

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- ; .

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Mix 2 , AC·20P Temperature = 50 C

8 · 10 12 14 16 18 20

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Profiles Temperature = 50 C

---~- - '

100 125 150 175 200 225 250 Wheel Position

AI2

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Of'--.-.

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Profiles Temperature = 55 C

14 16 18

........... ............ ....... . - ....... ......

25 50

........... , .. '.

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AI3

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Mix 2, AC·20P Temperature = 60 C

-----... r----.. r-----

2 4 6

.........

8 10 12

No. of P .... e. (Tb~L!.~nd .. )

Profiles Temperature = 60 C

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Mlx2,AC·20 Temperature = 45 C

. ,

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Profile8" Temperature '= 60 C

14 15

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Mlx2,AC·20 Tempera.ure = 50 C

.

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No. of PUles (Tbou .. ~d.)

. Profiles Tempera.ure = 60 C

14 15

7' 100 12', 1~ 175 200 225 2~

A16

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100 12~ 1:;0 175 Wheel PiI8l1lo'n - -

A17

14 16 18 20

12000 , •••••

200 22:) 2:;0

Mix 2, AC-10 Tamperalure = 45 C

0

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c .11 .. ·8 .. !!

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Al8

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0 I'----.

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0

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.

\ ., \ . ,

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14 16 18 20

SOOOPass ..

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A19

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£ E ::J

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0

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Mlx2,AC·10 Temperature = 55 C

~ .

8

\

. . . .

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, 12

No. of Pas ••• (Thou •• nc;t.)

Proflle8 Temperature = 55 C

.

14 18 18

·14+--1---1--'-+--+--+--+-+--'-1---1--1

·16+--1---1--'-+--+--+--+-+--1---1--1

·18+--1--I--+--+---I--+--+--1--'-f--j

·20+--f---11---t--4--+--j--+-~f---11---I o 2~ :10 75 100 12~1~0 175 200 22~ 250

- WhOel Po$l1l9n

A20

20

1000 Pe ....

3OOOP .....

E E-c

.S! " .. f n. ~ E " E .~

::;;

0

-2

-4

-6

-8

-10

-12

-14

-1 6

-1 8

i

! , i :

, .

Mlx2, AC-5 Temperature = 40C

-20 o 2 4 6 8 10 12 14 16 18 20

~ :

No. of Passes (n1ol.niand~j

Profiles Temperature = 40 C

-8+---,--f---+~-+--+_...-,.j.c...,.--__+_-+_-+__I-__1

~ -10t----t----t----t----r----r--~~~~--_+----+_--_1 .!! ~ -12t---i----r---t--~--~~--t_--t_--_r--_t--_+

I!

~ -14+--f----+-__+_--+--+--+-_I---+--+---1

-16+--+-_I---+--+--I---+---f----+-__+_---/

-18+--t---t---j---+---I---+--f----+-__+_---/

-20+--!-----I--+--+--'--I---+----1I----+-__+_---1 o 25 50 75 100· 125 150 175 200 225 250

Wh~81 Pcisitlon

A21

10000 Puses

15000 Passes

20000Puses

E E-c

_9 .. .. I!! "-1: E " E 'x • :IE

~

E E ~

c .2 .. i! ... E .. '" I! .. > «

0

-2 ~

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

0

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20

2

~ ~

4

'"

Mix2,AC-5 Temperature = 45 C

'"

6

"'-

8

~ \

I\J. . "-

I' --

)0 12.

No. of Passes (Thou •. B~d.)

~

Proflle.s­remperal!lre- = 4,5 C

'. " ,-'\.~.'." '\.

\.. .. ~ .. ,

/ 'rv"/

;

... i

14 16 18

0 2~ 50 75 100 12~ 150 17~ 200 22~ 250 - Wheel Position - -

A22

20

0,--2

-4

E S -6 c

.11 -8 m m ! a. .s E ~

E .~

::;

-10

-12

-14

-16

-18

-20

Mix 3, AC-20P Temperature = 45 C

, ,

0 2 4 8 10 12 14 18 18 20

~

E !. c .2 ., '" .. ~

a. S .. at f! .. > <C

-6

-8

-10

-12

-14

No. of Passes (Thousanda)

Profiles Temperature = 45 C

-16+---+---+---1---1---1---1---1---1----r--~

-18+--1--1-'--+--+-+-+--1--+--+--1 -20+---+---1---1---1---1---1----r---r--~--~

o 50 75 100 125 150 175 200 225 250 whoiiolPoslllOn -

A23

1000 , • • s_

1OOOOh.,0

2ooooP ... ,"

E E

" _S! .. .. !! "-E E " E -~ :::;;

E oS c .e .. "' D ~

l>-

S .. '" I! .. >

<C

0

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

0

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 0

2 .

4 6

Mix 3 • .AC-:;!OP Temperature;" 50 C

-----

8

~ '--

.. : .

.

10 12

No_ of P .... e. (Thou.ends)

Profiles Temperature", 50C

.

~

14 16 18

25 50 75 100 125 150 17~ 200 22~ 250 Wheel PO$illon

A24

.

-----......

2 0

10000Puses

E E-&:: .Il .. .. l! ... £ E

" E .~

::;

~

E !. " .2 .. .. u ~ ... ! • '" .. ~

~ <C

0

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

0

-2

-4

-8

-8

-10

·12

-14

·16

-18

~

--....

.

2 4

.. -..

'"~ \. '- '" ....

"\

Mix 3, AC-2DP Temperature = 55 C

-.... ........ "-~ ~

6 8 . 10 12

No.ofP ...... (Thousaride)

Proflle.8 Temperaiure = 55 C

.. ...... ""';.

\ \.

\

j

./

~

'" 14 16

""-I'--

""-

18 20

10000 P.sses

-20+---+---+---~--~~~--~--~--~--~--~ o 75 100 125 150 175 200 22:5 250

Wheel PciSiliot!

A2 5

0

2

E 5 -6 c .2 ~8 • ! Q. ·10 ! E ·12

. :J E .~ ·14 ::;;

E E ~

c .S! .. .. I! I>.

! 0

'" .. ~

0

~

·18

·18

·20 o

0

-2

-4

~

-8

-10

-12

-14

-16

-18

-20 0

2 4

.

50

----

Mlx3, AC·20 Temperature = 40 C

"--..

'" ., '" "-.. ~

~ ~ ~

6 .. 8 10 12 14 16 18 20

No. of Passes (Thou •• nda)

Profiles · Temperature = 40 C

:.­,,_ .. " .':' ,.

\ f

75

... '. "... . ... .. ~~ .. ... ......

100 125 150 175 200 225 250 Wheel Position

A26

10Q0Pasa.,

10000P •• aes

1tiOOOPa ....

20000Pa ....

E 5 c

.11 • • !! c. £ E ::I E 'x " :::;

~

E !. c .S! .. .. .. ~

"-.5 .. '" I! !e CC

0

-2

-4

-6

-8

-10

-12

-14

-18

-18

-20 o

0

-2

-4

-6

-8

-10

-12

-14

-16

·18

-20

~ t'---..

2

0 25

' i"',.

4

'"

8

Mlx3. AC·20 Temperature = 45 C

'\ \

f\

8

\ \

\ 10. 12

No. of Passes (Thou •• nd.)

. Profiles Temperature = 45 C

, . /

,.' f

14 16 18

~i ," , ;

7:1 100 125 150 17:1 200 22:1 250 Wheel P""ltion

A27

20

0

-2

-4

E E. -6

c .2 -8

i Q. -10 E E :J

.Ii

:i

-12

-14

-16

-18

-20 o

""'\

" \

2

\

""

4

\

Mlx3,AC-20 Temperalure = 50 C

-

1\

6

\

\ \

10 12

No. of Passel (Thou.lln~.)

Profiles Temporalure '" 50 C

14 lS 18

-20+---r---~--~~--~---+---+--~--~--~ . 0 :;0 7:1 100 12~ 1~ 17:5 200 22:5 2~

- - Wh''''1 Position

A28

20

E 5 r:: .2 .. . .. f a. £ E " .5 " " ::;

E g c .2 • • I! "-

oS u co .. ~

~

0

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

0

-2

-4

~

-8

-10

-12

-14

-18

-18

-20 0

---

2

25

-- I-..

Mix 3, AC-l0 remperature = 35 C

-----... ----., ~

'---... N ~ ~

4 6 8 10 12 14 16 18 20

--. "0.-

50

No. of Passes (Thou.end_)

Profiles Temperature = 35 C

- ~" '.'

,~

" ,,-

75 100 125 150 175 200 225 250 Wheel PoSition

A29

1000P .. ses

1OOOO"".es

E E-c .9 " " ! c. 1: E " E

.~

::;:

~ e g c .2 .. .. .. ~

a. ! .. '" I! .. :> c(

0

· 2

· 4

·6

·8

·10

·12

·14

·18

·18

-20 o

0

. ·2

·4

·6

·8

-10

-12

-14

·16

-18

·20 0

~ ~

Mlx3,AC-l0 Temperature = 40 C

""'" '\

"---. r---..

" i'--

-

~ .

~ '-t,

, '~ .

2 4 6 e 10 12 14 18 18 20

,- " -"-~ . .,

.'

No. of Passe. (Th,ou •• wl:CI.)

Profiles Te"pera,_ =40.C .

. , c.

• j

/

25 :50 75 100125 150 175 200 225 250 ·Wheel .Poshlon--

A30

1000 Pas • .

11000 P ••••

20000 P •••••

E !. t: .Il .. .. ! a. 1: E :> .!; " a ~

~

E E ~

c .!! CD CD D ~

"-.5 D

'" .. ~ .. >-...:

0

-2

-4

-6

-8

-10

-12

;1 4

-1 6

-18

-20 o

0,

-2

-4

~6

-8

-10

-12

-14

-16

-18

-20 0

----

Mix3. AC-5 Temperature - 35 C

"" " '" ...... ~

-

I-........... "\

1\

\

2 4 6 10 12 14 16 18 20

I"

25 50

••••••••• A"

No. of- PaGiles (Tho.uBlIndll

Profiles Temperature = 35 C

'--,..

IV

75 100 12~ : 150 17~ 200 22~ 250 - ·WhOel -P"oiiltiOn·

A31

10000P.~s"

15000 PIt$Sft

20000 Passes

o~ -2

-4

E S -6

c .Q ·8 m

! D.. ·10 ! E -12

" oS :I -14 ::;

E E ~

c .!! •

-16

-1e

-20 o

0

-2

-4

-6

-8

2

i -~ \ -

4

,

J \

Mix3, AC-5 Temperature = 40 C

1

\

-

6

\ \

8

-

\ 10 12

No~ of Passes. (Thou.and.)

proflies Temperatura = 40 C

'" - 1'1.... --- -- I 'c -. - V I-:-\'" "/ :." " ""

-

14 18 18

! • I! -10

\~ . l j ...

oS 0 -12 '" I! -14 !

-16

-18

-20 O. 25 50

'" "r;"

;

.! f ,

75 100 · 125 150 175 200 225 250 • Wh.iefPCi$liion -

A32

20

1000 P ... es

0

-2

-4

E .§. -6

c .11 m -8 m f

-10 Co

E E -12 ::J E

.~ -14 :::;

-18

-18

-20 0

0

-2

-4 E !. -6 c .S! -8 .. .. ! -10 ... ! II -12

'" I! -14 II

~ -16

-16

-20 0

2 4

25

Mix 4, AC-2DP Temper.lure = 40 C

6 8 10 12 14 16 18 20

No. of Passes (Thou.and.)

Pro.flles Temp.ralure = • C

75 100 125 150 175 200 225 250 Wheel Paslllorr -

A33

20000'''.8

0

-2

-4

E E. -6

~

.2 .. -8 .. ~ -10 a. E E -12 ~

.~ • -14

~ -16

-18

-20 0

0

-2

-4 ~

E oS -6 c .2 -B " " ., ~ -10 a. ! II -12

'" If ~ -14 ~

-16

-lB

-20 0

2 4

25 50

Mix 4, AC·20P Temperature = 45 C

8 10 12

No. of Passel (Thou •• nda)

Profiles Temperature = 45 C

..... ~ ..

14 16

7:5 100 12:5 150 17:5 200 22:5 250 . Wlieel Position

A34

18 20

10000 , •• su

20000 Pass ..

J

E !. c

.11 ... .. !! Q.

.£ E " .Ii :I ~

~

E. E ~

c .2 .. <II

" ~ Q.

! " ... I! " ,.

0;(

0

·2

·4

·6

·8

·10

·12

·14

·16

·18

·20 o

0

·2

·4

-6

·8

·10

·12

·14

·16

·18

·20 0

2

....

.

4

........ .............

50

M'lx 4, AC·20P Temperature = 50 C

'-.............

6 8 10 12 14 16 18 20

No. of P ...... (Thousand.)

Profiles Temperature = 50 C

------. " ............ ... -'.

. .

7:1 100 125 150 17:1 200 225 2:10 WhOa ("Position' .

A35

10000 PUS"

0

-2

-4

E !. -6

c .11 .. -8 .. f

-10 "-1:; E -12 ::I E ';(

• -14 :::;

-16

-18

-20 0

0

-2

-4 ~

E E -6 ~

c .l! -6 .. .. I! -10 ... ! D -12

'" II ~ -14 D :-..:

-16

-18

-20 0

2 4

25 50

8

Mix4,AC-20 T .... perature = 40 C

8 10 12

.No. Qf .Passes: (Thou.and.)

. Pro.fllss Temperature = 40 C

14 18

75 100 125 HID 175 200 225 250 - Whf"el PCI"shlon -

A36

.

18 20

1000P ....

1S000P"SK

E 5 " .S! .. .. .. ~ n.

.E E " E Ox a :;

~

E E ~

c .2 co .. .. ~

G-

! .. ... I! ~ «

0

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

-6

-8

-10

-12

-14

-16

-18

-20

1"-

0

2 4

. .

Mlx4, AC-20 Temperature = 45 C

. .

.

~ ---.,

6 8 10 12 14 16 18 20

No.of·P ...... (Thou.and.)

.. profliell ;. . Temp." .. ;'re = 45 C

. '

..

.

7:1 100 12~ .. 1:10 1~ 200 225 2:10 - Whi,," PciShlon -

A37

1SOO0P .....

ZOOOOP ... es

E ,g. <:

.Q .. .. I! 0-j; E " E .;;

" ::;

'i !. c .2 .. .. .. ~

a. ! " ... f

!

0 r----.. . -2

-4

-8

-8

-10

-12

-14

-18

-18

-20 o

0

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 0

2 4

\-,

. 6

Mlx4, AC-20 Temperature = 50 C

--

- .. 8

~ ~

..

10 12

Np.ofP_s (ThQu •• ndi:)

Profiles Temperature = 50 C

- .,. .. ,,, !

"-. "-,.

"

-14 16 18

.-....... j;

7:i 100 12:) 1M 17:1 200 225 2M WheefPosition

A38

20

15000 ........

0

·2

·4

E .s- ·6

c: .11 :I

-8

! ·10 Q.

E E · 12 ::I

. ~ ·14 ::;

·16

·18

·20 0 2

0

·2

·4 ~

E E ·6 ~

c .2 ·8 .. ., Ie ·10 ... .5 .

0 ·12 '" II ~ ·14 0 > c(

·16

·18

·20 0 2:1

Mlx4,AC·10 Temperature '" 40 C

. ..

.

4 6 8 10 . 12 a 16

'No. of Puses CThou •• n~.) .

Profllss Te .. perature '" 40 C

_ .... , ... --w ••• • .. •• ... • A .. _-

:10

'. ., .. : ~ ./ .. '

/

I

~'.'." .. ...­•..

7:1 100 · 12:1 1:10 175 200 225 2:10 Wiiee. PositlOn- -

A39

1'\.

"

18 20

10000hu"

zOOOO .......

E .§. c

_9 m • ! "-.§ E ~

E ~ :::;

0,,---2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

0

-

2 4 6

Mlx4, AC-10 Temperature = 45 C

--~

8 10 12 No_ of P ......

(Thou.and.)

Profiles Temperature = 45 C

14

~ ~

'\

16 18 20

-2 --. . ... "'.- --~-. - . -- 1000 PiIIss ..

-4 ~

E !. -6 c .2 -8 • • .. ~ -10 D-

! .. -12

'" f! -14

~ -16

-18

-20 0

.. . ...... u •••

25

--..•.. •........ , --. /

.' /~

\. ."" .. r'

' .......

75 100 125 150 175 200 225 250 - Wheel PoSitrOn-

A40

15000Pn •••

E 5 c

.11 • D

f "-E E " E .~

~

~

E S-c

.S! co .. ! ... ! 0

'" I! 0

~

0

-2

-4

-6

-8

-10

-12

-14

-18

-18

-20 o

0

-2

-4

-6

-8

-10

-12

-14

-16

-18

I'--I'---. '--..

"-\

2 4 8

MIx 4, AC-l0 Temperature = 50 C

\ \

"\

8

'\

1\ .l.

10 12

No. ofP ...... (Thou •• nd.)

Profiles Te"'perature = 50 C

~I-:!.--.. - ___ .-_-_- t---.. ---.. , ~~ ......... - . ' . , - '.

\

\. "-

";" .... ~ ........... .. ... !

14 18

/ ' ,

!

-20+---+---~--~~~-4---+---+--~--~--~ 25 :lO .- ... ., -I! 225 75 150 175 '200 100 125

Wheel Position

A41

18 20

3OOOP .. so

Mlx4, AC·S Temporalure = 35 C

o~

2

-4

E .s ·6 c:

.51 :: ·8

f ·10 Q.

! E ·12 " .!i :i ·14 ::;

-16

·18

·20 0

0

-2

-4 E E -8 ~

c .!! -8 CD CD U ~ -10 ... ! 0 -12

'" .. ~ -14 .. > <,

-16

-18

-20 0

2 4 8 10 12

No~ ii1f'u.et (Tho.u •• n.da)

Profiles' T .. mperal~re = 35 C

14

--- ......•....... _ .. -......... " . ,.;,.. "" .... - .'-- / . ".-. . .. , .. ..... .... ":,.. .... ~;. .......... .. .... ~.~.;. ..... ' ........ ~ ..... ~ .......... ,. ............ , ;.~~

'16

. 2~ 50 75 100 12~ 150 175 200 22~ 250 Wh8".-Pi>s-ilian -

A42

18 20

10000P"SH

0

·2

-4

E E ·6

" .Q .. ·8 .. f Il. ·10 .!; E ::I E .~

:::;

E E ~

c .s! .. .. I! ... .!; .. '" .. ~

D

~

·12

·14

·16

·18

·20 o

0

·2

·4

·6

·8

·10

·12

·14

·16

·18

·20 0

~

2

" '" -,

'"

\,\

"""" " '"

Mix 4, AC-5 Te/llperature = 40 C

\

'" ." "" \

8· 8 10 12

No. of Passu (Thou.ende)

Proflle.s r"mperalure = 40 C

" , '.

\ . .. .

14 18

/,

1/

.

\\ ~ J:

25

\ '-... / f ;

\

50

.. ' .. "

<' r

75 100 125 150 175 200 225 250 Whoiio, 'PosltiOn

A43

18 20

fOOOP.,,"

12000 ' .. ses

o ~

MIx 4, AC-S Temperature = 45 C

-2

'" -4

E .s. -6 I:

_11 .. .. ! "-! E " ! :l ::;

S-E ~

C .2 • • U ~

D.

.5 D

'" CO ~

u :. 00:

-8

-10

-12

-14

-16

-18

-20 0

0

-2

-4

-6

-8

-10

-12

-14

-16

-16

-20 0

2

~

" '-.

25 - -

\

4

-......•. -- ,-'---."

"" " ",' ............

6 8 10 12 No_ ofP .... e.

(Thou.and.)

Profiles Temperature = 45 C

-.:-~.~-- -~-~--. ---.. -." .. ,.-.-.....

" .

14 16

.-..... -... .................

/,'"

r. ....... ", , "'\ ~

\ ~.I'.,

"' "

!lO 75 100 125 l!lO 175 200 225 - - Whee"' PositiOn-

A44

18 20

100 'a.soK

300 .. asses

1000Passa.

3000 Passes

2!lO

Appendix B

Hamburg Wheel-Tracking Results from the Influence of Air Void Study

E E-r: .2 a a ~ Il.

J; E ~

E 'x G

::!;

E E r: .2 ~ ~ e a. J; E ~

E 'x a ::!;

0

·2

·4

·6

·8

·10

·12

·14

·16

·18

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0

·2

·4

·6

·8

·10

·12

·14

·16

·18

·20 o

2 4 6

~

2 4 6

Mix 1, 4.2% VOids Temperature = 50 C

'\ \

\ \

1'\

8 10 12

No. pf Passes (Thou •• nda)

Mix 1, 4.7% Voids Temperature = 50 C

"----

8

"-,

'" 1\ \ ~

10 12

No. of ·Passes (Thou .. nd.)

Bl

~ ~

" 14 16 18 20

' . ~

" '" "" 14 16 18 20

o

·2

·4

E .§. ·6 c .Il .8 " " !! Q. ·10 ~ E ·12 ~

£ ill ·14 :;

E .§. c

.11 .. • I! Q.

~ E ~

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::;

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0

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·4

·6

·8

·10

·12

·14

·16

·18

.20 o

r---.

2 4

2 4

8

6

Mix 1, 7.6% Voids Temperature = 50 C

8 10 12

No. of Passes (Thoueanda)

Mix 1,6.7% Vold8 Temperature = 50 C

-r--. r"\

" ~

8 10 12

No. of Passes (Tltouaand.)

B2

~ ~.

14 18 18 20

----~ ~

14 16 18 20

o

·2

-4

E E.. ·6 0:: ,9 .8 :: ~ ·10 £ E ·12 :J

.5 :!

::0

E E.. 0:: .g m .. ! Q.

£ E :J E 'x " ::0

·14

·16

·18 .

·20 o

0

·2

·4

·6

·8

·10

·12

·14

·16

·18

·20 o

r--~

"'\"

2 4

'-----. -.... "-

"-

'''''

2 4 6

Mix 2, 3.5% Voids . Temperalure = 50 C

,

"-

"y. .' ._ ....

.~

8 10 12

No. of Puses (Thou.and_)

Mix 2, 5.0% VOids Temperalure = 50 C

"',

8

~ ~,

""'" I'---

10 12

No. of Passes (Thousand_)

B3

'"' '"

14 18

~

14 18

''\

18 20

,

'"'---. 1", '\

18 20

E E. '" .2 G G

f Il.

£ E ~

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c .S! .. .. 0 ~ ... .§ E ~

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·4

·6

·8

·10

·12

·14

·16

·18

·20 a

0.0

·2.0

· 4 .0

·6.0

·8.0

·10.0

·12.0

-14.0

·16.0

·18.0

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2

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2

r--.

4

~

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6

~

Mix 2, 7.1% Voids Temperature = 50 C

'-. ...........

8

"'-~

"" I~

10 12

No. of Panes (Thousand8)

Mix 2, 8.7% Voids Temperature = 50 C

\ \

1\ \

'\

14

6 8 10 12 14

No. of Passe. (Thousands)

B4

16 18 20

16 18 20

0

2

4

E E. -6

" .11 -8 .. .. ~ -10 £ E -12 ~

E .~ .. 14 ::;

-18

·18

.

·20 o

~

2

0 ~

E E. " .11 .. .. !?

'" £ E ~

E .~

::;

-2

-4

-6

-8

-10

-12

-14

-18

-18

-20 o

"-

2

""

4

\

4

\.

8

\ \

6

Mix 3,5.6% Voids Temperature = 50 C

\ \

8

'.

\ \

\ .

10 12

No. of Passe. (Thouaend.)

Mix 3, 8.1% Voids Temperature = 50 C

,

8

.

10 12

No. of Passes (Thou.anda)

B5

14 16 18 20

14 16 18 20

E !. c

"ll • • ~ Il.

.E E " E "x ~ ::;

E !. c

.J! • a f Il.

.E E

" E "~ ::;

0

-2 1\ -4

-5

-8

-10

-12.

-14

-16

-18

-20 o

\

0

~ -2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o 2

2

\ \ ~

\ \

4 6

\ \

r", \

4 6

\

Mix 3, 9_6% Voids Temperature = 50 C

8 10 12

No. of Pass •• (Thousanda)

Mix3, 10_5% Voids Temperature = 50 C

\ \

~I

8 10 12

No. of Passes (Thou .. nd.)

B6

14" 16 18 20

14 16 18 20

E E.-~

.11 .. .. f "-E E " E .~

::E

0

-2

-4

-6

-8

-10

-12

-14

-18

-18

-20 o

-----~.

2 4

"- "

6

Mix 4, 5.7% Voids Temperature = 60 C

""

8

, " .

'-...

10 12

No. of Pu •• s (Thou8ande)

Mix 4, 7.5% Air Voids Temperature = 50 C

0

I----~

E E.-~

.11 .. .. ~ "-E E " E .~

::E

-2

-4

-s

-6

-10

-12

-14

-16

-18

-20 o

~ ,

' ......

2 4 6 8

"

10 12

No. of Passea: (Thou.and.)

B7

14 16 18 20

14 16 18 20

0 ~ I"---

E .5-~

.2 .. • ~ a.

.E E ::I E .;( II

:::;

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o 2

o~ 2

E .5-~

4

6

.2 -8 " " ~ c.. -10

.E E -12 ::I E

.~ -14

.:::; -16

-18 .

-20 o · 2

4

'"'-

4

Mix 4, 9.3% Voids Temperature = 50 C

~

8

~

6

8

'" 1\

\ \

I\,

10 12

No. of Passes (Thousands)

Mix 4,10.4% Voids Temperature = 50 C

"'"

8

\ \ \ .

1\ \

10 12

No. of Passes (Thou.enda)

B8

\

'\.

14 16 18 20

14 16 · 18 20

Appendix C

Hamburg Wheel-Tracking Results from the Short-Term Aging Study

E E-t:

_Q

!l ~ "-E

E ~

E 'x " :;:

E E-t:

.Q m m ~ a. E E ~

E 'x " :;:

0

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

0

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

"'-

'" \

2 4

2 4

\

Mix 1 , Short-Term Aged 0 Hours Temperature = 45 C

i

\ \ \ \

6 8 10 12

No. of Passes (T~ou$and8)

14

Mlxl, Short-Term Aged 2 Hours Temperal!'r .. = 45 C

16

"'" ~.

I

6 8 10 12

No. of Passes (Thousands)

Cl

.

14 16

18 20

~

------

18 20

0,--

-2

-4

E .s -6

c .2 -8 m m ~

-10 a. E E -12 ~

E ·x ·14

" :; ·16

-18

'20 0 2 4

Or--. ·2

·4

E E ·6

c . . 2 ·8 m m ~

·10 Q.

E E ·12 ~

E ·x ·14 " :;

·16

·18

· 20 0 2 4

Mlx ·1 .. Short-Term Aged 4 Hours Temperature = 45 C

~~

~

.

6 8 10 12 14

No. of Passes P:·hOU811~d.)

Mix 1, Short-Term Aged 8 Hours Temperature = 45 C

6 10 12

"No."ofPasses ·(th.~~.~n_d8)

C2

14

.'-.

"--"-

16 18 20

16 18 20

E E c .9 m m ~ a. E E " E 'x u ::;

E E c .9 m m ~ a. E E " E 'x u ::;

0

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

~

2

0 i"'--.

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o 2

Mix 2, Short·Term Aged 0 Hours Temperature = 45 C

-------~

4

4

6

~ \

\ \ ~

1\ \

8 10 12

No. ·of Passes (Thousands)

14

Mix 2, Shorl·Term Aged 2 Hours Temperature = 45 C

-,

6 8 10 12

No. of Passes (Thousands)

C3

14

.-

16 18 20

-

16 18 20

4

' Mix 2, Short-Term Aged 4 Hours Temperature '= 45 C

". , ~

6'

:'

"

8, ,, ' 10 12 -Nb:·,of'J>asaes · . "(Th~~!~~~~) .. _.

14

Mix 2, Short-Term Aged 8 Hours Temper .. tur~ ,= 45 C

,

16 16 20

E ! -6+---~~-+---4----~--+---~---+--~~--+---~ c .g -8+----+----+-~_+--~t_~-+----t_--_+----t_--_+--~ m ~ ~ -10+---~----~--~+_--_+--~4_~--~~_+----+_----~--~

.E E -12+---~----~----+---_+--~4_----~--_+----+_--~~--~

" .E ~ -14+---+---+~~f----t--+--+---t----~--+----I

::; -16+-----~--_+----+----+----~----+_--_+----4_----~--~

,

-18+-----~--_+----+----+----~----+_--_+----4_----+_--~

-20+-----~--_+----+----+----4_----+_--_+----+_----+_--~ o 2 4 6 B 10 12

No~ of Passes (111 all.and.)

C4

14 16 18 20

S E c .2 ~ ~

~ Q.

E E ~

E .~

~ ::;

S E c .2 ~ m w Q. E E ~

E .~

~ ::;

0

-2 1"'--. -6

-8

-10

-12

-1.

-16

-18

-20 o

0

-2

-, -6

-8

-10

-12

-1'

-16

-18

-20 o

\ 1\ ~ \ \

2

2

•

Mix 3, Short-Term Aged 0 Hours Temperature = 45 C

\ \

6 8 10 12

No. of Passes (Thou •• nds)

,.

Mix 3, Short-Term .Aged 2 Hours Temperatllro = .45 C

~

~

~ ~

-------

16

'-------...

• 6 8

_.

. 10 12

No. of Passes (Thousllnds)

C5

,. 16

18 20

---~

18 20

E E.. t:: .2 .. .. ~ a. ~ E ~

E .~

" ::;

E E t:: .2 .. .. ~ a. ~ E ~

E .~

" ::;

0 1--

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

0

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 0

.

.

2 4

.

2 4

Mix 3, Short-Term Aged 4 Hours Temperalure = 45 C

6

~ "- ,

"-. "-.

- -.. :.-." ~

...

I

I .. 8 10 . 12

No:~Q.f ·~asi;tes­(Tho,u...ao"da)-

! ''- .,,-

.. .. .

14

Mix 3, Shorl,Titrm Aged:·6Hours Toniperaiure ·=~5 C .. :: .

6 8

.

10 12

N.c. of Pass_es (T~ou.8.nd8)

C6

14

"- "-,

~

16 18 20

16 18 20

E E c .9 m m ~ a. E E ~

E ·x G ::;

E .5-c

.Q G ~

~ a. E E ~

E ·x " ::;

0

-2 " -4

-6

-8

-10

-12

-14

-16

-18

-20 o

0

'-.,., ~

2

'----2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o 2

"-

Mix 4, Shorl-Term Aged 0 Hours Temperature = 45 C

I'\. \

4

4

I

\

1\

6

6

\

8 10 12

No. of Passes (Thousands)

Mix 4, Aged 2 Hours T.emperature = 45 C

..

B 10 12

No. of Passes (Thouunds)

C7

14

14

16 18 20

16 18 20

E E-c

.2 • " ~ a. ! E , E •• • ::;

E E-c .2 • " ~ a. ! E , E •• • ::;

0 I'---

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

0 I'---

-2

-4

-6

-8

·10

-12

-14

-16

-18

-20 o

2 4

2 4

Mix 4, Short-Term Aged 4 Hours Temperature = 45. C

r--...

--------------I--

.

6 8

.

..

..

.-.. ...

..

10 12

No.-,ot. P,~ses . . (fho'u8Bnds) - -c- •..

14

Mix 4, Short4e-rm:.Ag~d II Hours Temperature = 45 C

..

.

.

6 8

.. . .. ....

. I

...

..

.

10 12

No.-of Passes (Thou8ends)

C8

14

16

I

16

~

18 20

18 20

Appendix 0

Hamburg Wheel-Tracking Results from the Lime Mixing Study

E E-" .Q m m !! "-

.E E " E ·x " ::;

E E-" . Q m m !! "-E

E " E ·x " ::;

0

"--2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

0

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

2

.

2

Mix 1 with Zero Lime and Zero Water Temperature = 45 C

"'\

\ -

.. .. \ •....

4

4

6

"-\

". "'"'

8 10 12

. No. of·"Pass-es rri1ou~ands)

'\ \

14

Mix 1 will:! Lime and Zero Water Temp.e",tl!re = 45.C

.

6 8

.. ..

. 10 12

No. of-Pa~ses (Thou$ands)

Dl

14

.

18 18 20

.

16 18 20

0 ,,---

-2

-4

E E -6 ~

,Q -8 ~ 0

f -10 Q.

,

!: E -12 ~

E 'x -14 ~ ::;

-16

-18

-20 0 2 4

Mix 1 with Lime and 2% Water Temperalure = 45 C

6

,

".;. : " ...•. . "

8 , 10 12

No. of paSses . (Thou_linda)

14

Mix 'I wlth,'Llme·ahd -4% Water Temperal!"..,- =,45 C

6 8 ,12

No. of Passes "(Th:OJ,.l •• nda)

D2

,

14

16 18 20

16 18 20

E E

" . 51 m m ~ a. j; E ~

E ·x " ::;

E E-" .51 m m e a. E

E ~

E ·x " ::;

0 "-

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

0

2

"--------2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o 2

Mix 1 w/lime, 4% Water,"Mellowed" 72 hr Temperature = 45 C

~

.

.. . .. ... .; -

-

4 6 8 10 12 14 16

No. of Passes (Th ousarids)

Mix 2 with Zero lime and Zero Water Temperature = 45 C

~

4 6

.

"" '"

...

8

~

"\ \,-

10" 12

No. of 'Passes (Thousands)

D3

'\

\ \

14 16

I'---.-

18 20

18 20

o

-2

-4

E E -6 c

.Q -8 o o ~ Q. -10 E

E -12 ~

E .~ -14

::; -16

-18

1-----

-20 o

0

2

"--...

E .s c .2 0 0 G a. E

E ~

E ·x a ::;

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o 2

4

4

Mix 2 with lime and Zero Water Temperature = 45 C

I

-----

6 8 10 12

No. of Passes (Thousands)

14

Mix 2 with lime and 2% Water Temperature; 45 C

6

.

------~

8

~

'"" I

10 12

No. of Passes (Thousands)

D4

........ ~

14

16

i'--

16

------

18 20

" ~. '"'"

18 20

E E c

,Q ~ m ~ "-E E ~

E 'x ~

::;;

E E c

.Q m ~

~ "-E

E ~

E 'x ~

::;;

0

I~ -2

-4

-6

-8

-10

-12

-14

.,;16

-18

-20 o

0 '----

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

2

2

,

, ,

4

Mix 2 with Lime and 4% Water Temperature = 45 C

"

I "

,

"

~ , , .

, ,

-

6 • , 8 ,_10~ 12

No. ;of:Passes (Th'oi.J.sands)

"

14 16

MIx 2 w/Lime,4% Water,"Mellowed" 72 hrs Temperature"; 45 C

-

4 6 8

•

,

:

"

10 12

No. of Passes (Thousands)

D5

14 16

I

~ ~

""""

18 20

18 20

E E-c .2 m m f a. .£ E ~

E .;( G ::;

0

-2 ~ -4

-6

-8

-10

-12

-14

-16

-18

-20 o

.

2

Mix 3 with Zero Lime and Zero Water Temperature = 45 C

~ ~

4

~ "

6

"-

8

~ "-

\

. ". --,.: '

10 12 No·. of Passes . :(Tho:unnda)

, \

14

Mix 3 with Lime and Zero Water Tempe.ralure = 45 C

16 18 20

E E- -6+---~---+--~----t---~--~---+--~~--+---~ c

.~ -8t---~L----t----t----t--c .... :~ ... ~~--r---_t. __ --~----r_---1

~ a. -10t---~~---t----t-~-t--__ ~--~r---_t--~~----r_---1 .£ ..• E -12 t-----t------i----t-----t-'"'"'----i,------+----+~___if_--+_--___1

E · .~ -14t---~----_t----r-~_t----~----r_--_t----+_--~r_--~ ::;

-16t---_+----f_--+_---+~--f_--+_--_+--'----f__--+--___1

-18t---_+--~f_--+_---+-----if_--+_--_+----f__--+--___1

No~: .'ci.f ·.~as~es · · . tTh.~us8nd8)

D6

E E-c _2 .. .. ~ "-E E ~

E 'x II :;

E E-c .2 .. .. ~ "-E

E ~

E 'x .. :;

0

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

0

-2

-4

-6

-8

-10

-12

-14

·16

-18

-20 0

.

2 4

2 4

Mix 3 with Lime and 2% Water Temperature = 45 C

r-..

~ ..

----------~

~

.... ...

. . .

6 8 10 12 14

No ., of Passes (Th"oussnda)

Mix 3 with Lime aild 4% Water Tempe·rature = 45 C

6 8 . . 10 12

No.:O{Passes. (Thousands) -

D7

.14

~ ""-.

16 18 20

16 18 20

E E c .2 m m m ~ .£ E ~

E ·x c ::;

E E c .2 m m f "-E

E ~

E ·x c ::;

0 f"'-..

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

0

'-----2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

2

2

Mix 3 wjLlme, 4% Water,"Mellowed" 72 hr Temperature = 45 C

4 6

.-

8 10 12

-. No. Ci'f Passes (Thousands)

.....

14

Mix 4 with Zero Lime and Zero Water Temperature = 45 C

.

4 6

-----~.

. I

8

...

~

.

-10 12

No. of Passes (Thousands)

D8

~ I~,

14

.

16

I"

16

-----

18 20

'\

1\

\ 18 20

E E c . 9 m m

" ~ a. .E E ~

E .~

a :::;;

E E c .9 m m ~ Q.

E E ~

E .~

a :::;;

0 I'--

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

0

-2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o

'----

.

.

2 4

2 4

Mix 4 with Lime and Zero water Temperature = 45 C

..

-r----.-

..

6

,

. .

.<

8 -, .111

N~.:-af Pilsses (ThoI:l8snds)

I· .

14

Mix4with Lime and 2% Water Temperature:' 45 C

' . I

6 8 ,

H)· . 1.

No. of Passes (Thousands)

D9

.

14

16

.

16

~

.. .

18 20

--

18 20

0 I"---..... -2

-4

E E -6

t: _2 -8 .. .. !! "- -10

.E E ~

E -x " ::;

E .s t:

_2 .. .. 1! "-E

E ~

E -x " ::;

-12

-14

-16

-18

-20 .-0

0

"'"'--2

-4

-6

-8

-10

-12

-14

-16

-18

-20 o 2

2 4

Mix 4 with Lime and 4% Water Temperature = 45 C

6 8

-

-

10 12

No. of Passes (ThO'Ussnd-s)

14 16

Mix 4 w/Lime,4% Water,"Meliowed" 72 hrs

-

4 6

Temperature = 45 C . :.- ..

8

. . -

10 12

No. of Passes (Thousands)

D10

: .

------ I'-----

14 16

-

18 20

--------~

18 20