TRB Superpave Abstracts 2002
81st Transportation Research Board Annual Meeting
WashingtonD.C.
January 13-17, 2002
Table of Contents
1.Statistics for Superpave HMA Construction QC/QA Data
- Coarse Versus Fine-Graded Superpave Mixtures: Comparative evaluation Of Resistance To Rutting
- Prediction of the Viscoelastic Response and Crack Growth in Asphalt Mixtures using the Boundary Element Method
4.Rotary Loaded Wheel Testing For Hot Mix Asphalt Quality Control
- Effect of Aggregate Structure on Rutting Potential of Dense-Graded Asphalt Mixtures
- Zero Shear Viscosity of Asphalt Binders
7.Impact of Different Types of Modification on Low Temperature Tensile Strength and Tcritical of Asphalt Binders
8.Target And Tolerance Study For The Angle Of Gyration Used In The Superpave Gyratory Compactor (Sgc)
- Online Tools for Hot-Mix Asphalt Monitoring
- Blue Earth County CSAH 20 – An Engineered Cold In-Place Recycling Project
- Effects Of Permeability And Vehicle Speed On Pore Pressures In Hot Mix Asphalt Pavements
- The History and Future Challenges Of Gyratory Compaction 1939 to 2001
- Comparison of Fundamental and Simulative Test Methods for Evaluating Permanent Deformation of Hot Mix Asphalt
- Field And Laboratory Characterization Of Asphalt Mixes For The Design Of Flexible Pavements
- Round-Robin Study For Field Permeability Test
- Shear Properties as Viable Measures for Characterization of Permanent Deformation of Asphalt Concrete Mixtures
17.The Effect of Various Aging Techniques on Asphalt Low-Temperature Properties
- Aggregate Blending forAsphalt Mix Design: “The Bailey Method”
19.Effect of Crumb Rubber Particle Size and Content On The Low Temperature Rheological Properties of Binders
- Precision Statements For The Ignition Oven Using Plant-Produced Mix
21.Dynamic Modulus of Asphalt Concrete Using a Hollow Cylinder Tensile Tester
22.Use of Stiffness of Hot-Mix Asphalt as a Simple Performance Test
- A Simple Performance Test For Fatigue Cracking Of Asphalt Concrete Based On Viscoelastic Analysis of Indirect Tensile Testing And Its Validation Using Westrack Asphalt Mixtures
24.Determination of Moisture in HMA and Relationship with Tender Mix Behavior in the Laboratory
- Establishing Variability for Hot-Mix Asphalt Construction in Arkansas
- Measurements of Aggregate Texture and its Influence on HMA Permanent Deformation
- Simple Performance Test for Permanent Deformation of Asphalt Mixtures
28.Effect of Fine Aggregate Angularity (FAA) on Compaction and Shearing Resistance of Asphalt Mixtures
- Examination of Aggregate Degradation and Effect on Volumetric Properties
30.Quantification of Coarse Aggregate Angularity Based on Image Analysis
- A Performance-Graded Binder Specification for Surface Treatments
32.A Standardized Procedure for Analysis of the Dynamic Modulus (|E*|) Data to Predict Asphalt Pavement Distresses
- Determining Air Void Content of Compacted HMA Mixtures
- Illinois’ Extended Life HMA Pavement Specifications
- 2-D Image-Based Volumetric Modeling for Crushed Limestone Aggregates
36.Application of the Digital Image Correlation Method to Mechanical Testing of Asphalt-Aggregate Mixtures
- Determining the Low-Temperature Fracture Toughness of Asphalt Mixtures
- Effect of Wearing Surface Characteristics on Measured Pavement Skid Resistance and Texture
- Effects of Microstructures on the Deformation Characteristics of Modified Asphalt Mixtures at High Temperature
- Evaluation of Performance of Full Depth Reclamation (FDR) Mixes
- Evaluation of the Performance of Pavement Sections Constructed in Grand Teton National Park
- Laboratory Simulation of Field Compaction Characteristics on Sandy Soils
- Measuring and Defining Fatigue Behavior Of Asphalt Binders
- Micromechanical Analysis of the Viscoelastic Properties of Asphalt Concretes
- Three-Dimensional Aggregate Evaluation Using X-ray Tomography Imaging
- Characterization of Aggregate Shape Using Fourier Analysis and Digital Imaging Technique
- Construction-Related Asphalt Concrete Pavement Temperature and Density Differentials
- Prediction of Daily Temperature Profile in Flexible Pavements
- Procedure for Monitoring and Improving the Effectiveness of Quality Assurance Specifications
- Rutting of Asphalt Pavements in Manitoba And Relationship To Strength and Deformation Properties
- The Pavement Design, Construction, and Materials Enterprise at Michigan Technological University
- A Laboratory Study of Full Depth Reclamation (FDR) Mixes
- Analysis of The Statistical Distribution of Failure Stress Values Determined Using The Superpave Direct Tension Test
- Application of The Rolling Dynamic Deflectometer To Project-Level Pavement Studies
- Evaluation of Fatigue Healing Effect of Asphalt Concrete by Pseudo Stiffness
- Measurement of Vertical Compressive Stress Pulse In Flexible Pavements and Its Representation For Dynamic Loading Tests
- A Probabilistic Model for Prediction of Asphalt Pavement Crack Depths
- An Analytically-Based Approach to Rutting Prediction
- Analysis of Bituminous Crack Sealants by Physico-Chemical Methods and its Relationship to Field Performance
- Wavelet-based 3D Descriptors of Aggregate Particles
- WesTrack Fatigue Performance Prediction Using Miner’s Law
Statistics for Superpave HMA Construction QC/QA Data
Frazier Parker, Jr.
Director, HighwayResearchCenter
AuburnUniversity, Auburn, AL36849
Telephone No.: (334)-844-6284
Fax: (334)-844-6290
e-mail:
M. Shabbir Hossain
Assistant Professor, Civil Engineering Department
TexasTechUniversity, Lubbock, TX79409-1023
Telephone No.: (806)-742-3471 ext. 340
Fax: (806)-742-3488
e-mail:
ABSTRACT
Asphalt content, air voids and mat density measurements for Superpave mixes were collected during 1997, 1998, 1999 and 2000 to develop statistics for a statistical quality control / quality assurance program for the Alabama Department of Transportation (ALDOT). Data were analyzed to determine if accuracy and variability improved and stabilized as contractors accumulated experience with Superpave mixes, to compare contractor and ALDOT measurements, and to assess the effects of maximum aggregate size and design ESAL range. Analyses indicated accuracy and variability of asphalt content measurements for Superpave mixes remained consistent and comparable to Marshall mixes. Variability of voids for Superpave mixes stabilized but remained higher than variability of voids for Marshall mixes. The accuracy in achieving target voids for Superpave mixes deteriorated and stabilized at values poorer than achieved for Marshall mixes. Variability of mat density measurements for Superpave mixes decreased and stabilized at values comparable to Marshall mixes. The accuracy of mat density measurements for Superpave mixes improved but stabilized at values poorer than achieved for Marshall Mixes. There are significant difference between the measurements of contractor and ALDOT measurements. Asphalt content decreases as design traffic level and maximum aggregate size increase. The level of mat density achieved increases as maximum aggregate size increases.
KEY WORDS: Superpave, hot mix asphalt concrete, asphalt content, air voids, mat density,construction, quality control and quality assurance.
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Coarse Versus Fine-Graded Superpave Mixtures: Comparativeevaluation Of Resistance To Rutting
Prithvi S. Kandhal, Associate Director
NationalCenter for Asphalt Technology (NCAT)
277 Technology ParkwayAuburn, AL 36830
Phone: 334-844-6228
Fax: 334-844-6248
Email:
L. Allen Cooley, Jr., Research Engineer
NationalCenter for Asphalt Technology (NCAT)
Email:
ABSTRACT
Both coarse and fine-graded hot mix asphalt mixtures can be designed within the gradation control points recommended within the Superpave mix design system. However, some states have begun to specify only coarse-graded mixtures (below the restricted zone) and other states are specifying only fine-graded mixtures (above the restricted zone). This study was conducted to compare coarse-graded Superpave mixtures with fine-graded Superpave mixtures in terms of resistance to rutting so as to determine whether restrictions on gradations (either coarse- or finegraded mixtures) are justified.
Fourteen mixtures comprising two nominal maximum aggregate sizes: 9.5 and 19.0 mm; two coarse aggregates: granite and crushed gravel; and four fine aggregates: sandstone, limestone, granite, and diabase, were tested. Resistance to rutting of both coarse- and fine-graded mixtures was evaluated using three test methods: Asphalt Pavement Analyzer, Superpave shear tester, and repeated load confined creep test.
Statistical analyses of the test data obtained by the three performance tests indicate no significant difference between the rutting resistance of coarse- and fine-graded Superpave mixtures. It has been recommended that mix designs should not be limited to designing mixes on the coarse or fine side of the restricted zone.
KEY WORDS: Superpave, asphalt mixtures, HMA, coarse-graded, fine-graded, gradation, rutresistance, permanent deformation, creep test, APA, SST
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Prediction of the Viscoelastic Response and Crack Growth in Asphalt Mixtures using the Boundary Element Method
Bjorn Birgisson, Assistant Professor
Email:
Boonchai Sangpetngam,
Graduate Research Assistant
Email:
Reynaldo Roque, Professor,
Email:
Dept of Civil Engineering,
University of Florida
345 Weil Hall, P. O. Box 116580
Gainesville, FL32611-6580
Tel: (352) 392-9537 ext. 1458
Fax: (352) 392-3394
ABSTRACT
It has long been accepted that cracking of hot-mix asphalt (HMA) pavements is a major mode of premature failure. Many state agencies have verified that pavement cracking not only occurred in fatigue cracking in which a crack initiates from the bottom of the asphalt layer but also in other modes such as low temperature cracking, and the more recently identified top-down cracking. In order to improve current pavement designs and the cracking resistance of mixtures it is necessary to understand the mechanisms associated with crack initiation and crack growth in HMA mixtures. However, the complexity of the problem and the lack of simple-to-use analysis tools have been obstacles to a better understanding of hot-mix asphalt fracture mechanics and the development of better hotmix asphalt fracture models. Up until today, the well-known finite element method has been the primary tool used for modeling cracks and their effects in mixtures and pavements. Unfortunately, it is both complex and numerically intensive for fracture mechanics applications. This paper presents the displacement discontinuity boundary element method, which is a numerical method that has been very successful in many other engineering fields, as a potential method for modeling cracking in hot-mix asphalt mixtures and pavements. A series of examples are provided to illustrate the effectiveness of the method in dealing with cracks, crack propagation, and viscoelasticity in hot-mix asphalt. It was concluded that the method was easy-to-use, resulted in accurate solutions, required minimal computation time, and thus significantly simplified the modeling of crack-related problems.
Keywords: pavement cracking, modeling, numerical method, displacement discontinuity
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Rotary Loaded Wheel Testing Forhot-Mix Asphalt Quality Control
Chris Edgar (Principal) for
REGIS Engineering Solutions, Inc
3017-A Atlanta Highway
Montgomery, AL36109
Phone: (334) 272-0022
Fax: (334) 221-5204
ABSTRACT
Loaded wheel testing (LWT) of hot-mix asphalt (HMA) is commonly utilized for design verification, but the practicality of conventional equipment has not been conducive to quality control (QC) testing during production. Recent advancements in load mechanism design have resulted in the development of a simpler rotary loaded wheel tester (RLWT) that may produce QC results during production comparable to those generated via LWT during design. The National Center for Asphalt Technology (NCAT) prepared dual sets of QC-type samples in the SUPERPAVE gyratory compactor that were subsequently used to compare rutting susceptibility results from four different types of HMA mixes. The Asphalt Pavement Analyzer (APA) was used as the LWT standard for the study. Tested specimens revealed a predictable relationship between measured rut depths in the two devices, which would enable users to interchangeably use the RLWT to generate APA data for either design verification or to monitor as-built quality during production. Having established a correlation between APA and RLWT results, subsequent research sought to simulate testing in the production environment by varying the asphalt content in each mix slightly from design values. Subsequent data revealed that the RLWT detected increased rutting susceptibilities with increased asphalt contents, as would be expected. Thus, the RLWT may have promise in obtaining meaningful QC results at a plant during mix production.
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Effect of Aggregate Structure on Rutting Potential of Dense-Graded Asphalt Mixturesby
Bensa Nukunya, Post-Doctoral Associate,
E-mail:
Reynaldo Roque, Professor,
E-mail:
Mang Tia, Professor,
E-mail:
Dept of Civil and Coastal Engineering
University of Florida
124 Yon Hall
P. O. Box 116580
Gainesville, FL32611-6580
Tel: (352) 392-9537
Fax: (352) 392-3394
Yusuf A. Mehta, Assistant Professor
Department of Civil and Environmental Engineering
RowanUniversity
201 Mullica Hill Road, 329 Rowan Hall
Glassboro, NJ 08028
Tel: (856) 256-5327
Fax: (856) 256-5342
E-mail:
ABSTRACT
Superpave mix design as the name suggests was developed to provide superior performing pavements for the transportation industry. However, researchers and designers in their quest to provide such mixtures have encountered problems with some design specifications such as the restricted zone. Superpave recommends that designers avoid grading through the restricted zone to eliminate tender mixes and gradations that may be too close to the maximum density line. But studies into the performance of the restricted zone have shown that dense graded mixtures that violate this requirement have provided good performance. It has also been reported that mixtures that are graded below the restricted zone (BRZ) have poor rutting performance than those that are graded above the restricted zone (ARZ) or through the restricted zone (TRZ). It is also known that the minimum VMA requirement, which was established to ensure durability, is very difficult to achieve. This leads to over asphalting in BRZ mixtures, and compromises the resistance to rutting when the mixture meets the VMA criterion. The purpose of the paper is to examine the effect of aggregate structures on rutting performance of mixtures. Ten mixtures comprising seven limestone and three granite mixtures were used. Of these, six were BRZ mixtures and four ARZ mixtures. After investigating the behavior of the mixtures, it was concluded that BRZ mixtures developed different aggregate structures than ARZ mixtures and the performance of mixtures depended on their aggregate structures. It was observed that the high VMA requirement caused over asphalting in BRZ mixtures hence their dismal rutting performance as compared to ARZ mixtures.
Keywords: restricted zone, aggregate structure and rutting performance.
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Zero Shear Viscosity of Asphalt Binders
Dr. David A. Anderson, Professor
PennStateUniversity
201 Transportation Research Building, University Park, PA16802
Telephone: (814) 863-1912, E-mail:
Yann M. Le Hir, Formerly Visiting Researcher, PennState
Bitumen Development and Technical Assistance
51, Esplanade du Général de Gaulle
92907 Paris La Défense Cedex, FRANCE
Telephone: +33 (0)1-41-35-99-60, E-mail:
Dr. Jean-Pascal Planche, International Technical Strategy for Bitumen,
51, Esplanade du Général de Gaulle
92907 Paris La Défense Cedex, FRANCE
E-mail:
Didier Martin, Research Study Leader on Asphalt,
ElfResearchCenter, BP22, 69360 Solaize, FRANCE
E-mail:
ABSTRACT
Recently there has been considerable interest, especially in Europe, in the use of zero shear viscosity as a specification criterion for asphalt binders. This interest is precipitated by the apparent inability of the current Superpave criterion, G*/sinδ, to capture the contribution to rutting resistance afforded by polymer modification. Zero shear viscosity (ZSV) can be determined directly from long-term creep tests but such tests are time consuming and are often very difficult to perform. Several alternative methods for determining the ZSV have been proposed in the literature including extrapolation of the dynamic viscosity to zero frequency, applying the Cross model to dynamic data, and the superposition of multiple short-term, nonsteady state creep tests. In this paper a number of method for determining the ZSV from both creep and dynamic data are evaluated. Laboratory test data for ten different unmodified and modified binders was obtained through a series of creep and dynamic experiments. ZSV values obtained from two of the more promising methods are compared along with a comparison of the ZSV ranking with the Superpave grading temperature. The authors concluded that two of the methods provided very similar values for the ZSV when applied over a considerable range in test temperature and that the results from the two methods can be used interchangeably for the materials that were tested. The binders ranked quite differently when ranking according to their Superpave grading temperature or their ZSV.
Keywords: Asphalt binder, Zero Shear Viscosity, Superpave grading, creep testing
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Impact of Different Types of Modification on Low Temperature Tensile Strength and Tcritical of Asphalt Binders
Susanna Man Sze Ho and Ludo Zanzotto
University of Calgary
2500 University Drive NW
Calgary, AlbertaT2N 1N4
CANADA
Phone: 403-220-8077 and 403-220-8918
Fax: 402-282-7026
e-mail: and
Daryl MacLeod
Husky Energy
P.O. Box 6525, Station D
Calgary, AlbertaT2P 3G7
CANADA
Phone: 403-298-6304
Fax: 403-298-6161
e-mail: Daryl.Macleod@huskyenergy.
ABSTRACT
Since the introduction of the Superpave asphalt binder specification, the asphalt industry has a useful guideline to choose appropriate materials to meet the requirements of a specific climatic locale. Acid, alkaline and polymer modification are just some of the ways to modify asphalt to meet the Superpave specification. The Direct Tension Test (DTT) technique was applied to study the low-temperature properties of modified asphalt in terms of DTT failure stress values and the critical cracking temperature (Tcritical). The Bending Beam Rheometer (BBR) usually failed to detect the improvement in low-temperature performance in polymer modified asphalt (PMA). The DTT results show that polymer modification with elastomeric type polymer improves the low-temperature performance of PMA. In some PMA, the failure stress value was higher than 9.5 MPa. The DTT technique for PMA is also discussed.
The effect of acid or alkaline modifiers on asphalt materials was also studied. It was found that acid or alkaline modification of asphalt is only temporary and can be reversed. Acid modification of asphalt can be reversed by reaction with alkaline materials such as lime or antistripping agents. Alkaline modification of asphalt can be reversed by reaction with acidic materials such as carbon dioxide. Alkaline can also be washed away by water. Even though BBR suggested a slight improvement in the low-temperature performance in acid or alkaline modified asphalt, the DTT failure stress values and Tcritical did not confirm this improvement.