Evaluation of Superpave Gyratory Compaction of Hot-Mix Asphalt

1996 ◽  
Vol 1543 (1) ◽  
pp. 145-150
Author(s):  
E. R. Brown ◽  
D. I. Hanson ◽  
Rajib B. Mallick
Keyword(s):  
Hot Mix Asphalt ◽  
Current Data ◽  
Average Difference ◽  
Density Data ◽  
Air Voids ◽  
Superpave Gyratory Compactor ◽  
Gyratory Compaction ◽  
Pavement Temperature

To achieve 4.0 percent air voids in laboratory-compacted hot-mix asphalt with the Superpave gyratory compactor, different gyration levels are currently specified in the Superpave manual, each applicable to a particular combination of traffic and maximum pavement temperature. Two 1-year-old and four 2-year-old in-place densities were compared to those obtained from Superpave compaction of laboratory-prepared specimens and from compaction of reheated plant-produced mixtures. The gyration numbers corresponding to in-place density fell below 100 for all the mixes. At similar gyration levels, density of compacted, reheated, and laboratory-prepared specimens indicated an average difference of about 1 percent. Current data show that the Ndesign, Ninitial, and Nmax gyration levels may be too high, at least for lower traffic. Evaluation of the currently specified Ndesign values will be refined when the 3-year in-place density data become available.

Strategic Highway Research Program gyratory compaction for predicting air voids of Saskatchewan SPS-9A asphalt mixes after 10 years of performance in the field

2012 ◽  
Vol 39 (8) ◽  
pp. 897-905 ◽  
Author(s):  
Aziz Salifu ◽  
Curtis Berthelot ◽  
Ania Anthony ◽  
Brent Marjerison
Keyword(s):  
Asphalt Concrete ◽  
Material Properties ◽  
Hot Mix Asphalt ◽  
Permanent Deformation ◽  
Test Site ◽  
Asphalt Mixes ◽  
Air Voids ◽  
Need To Evaluate ◽  
Gyratory Compaction ◽  
Compaction Method

Many Saskatchewan provincial highways exhibit permanent deformation that is mostly attributed to reduction in air voids in hot mix asphalt concrete surfacing. The Saskatchewan Ministry of Highways and Infrastructure (MHI) currently use the Marshall compaction method for hot mix asphalt concrete (HMAC) design and placement quality control and quality assurance. It has been found that the Marshall compaction method does not accurately predict field air voids. Therefore, MHI identified the need to evaluate the SuperpaveTM gyratory compaction method to predict field air voids of typical Saskatchewan asphalt mixes. This paper presents a summary of laboratory and field volumetric as well as rapid triaxial mechanistic material properties of typical Saskatchewan asphalt mixes. This research considered seven asphalt mixes from the Radisson Specific Pavement Study (SPS)-9A test site comprising two conventional Saskatchewan Marshall Type 71 mixes, five SuperpaveTM mixes, and a SuperpaveTM recycled mix. This research determined that Marshall compaction and the gyratory compaction at 1.25° gyration angle underestimate the collapse of field air voids. This research also showed that the gyratory compaction method at 2.00° angle of gyration more accurately predicted field air voids of the asphalt mixes constructed as part of test site.

Discrete Element Method (DEM) Analyses of Hot-Mix Asphalt (HMA) Mixtures Compaction and Internal Structure

2013 ◽  
Vol 639-640 ◽  
pp. 1287-1294 ◽  
Author(s):  
Jing Song Chen ◽  
Lei Zeng ◽  
Jian Yin
Keyword(s):  
Discrete Element Method ◽  
Hot Mix Asphalt ◽  
Coarse Aggregate ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Point Of View ◽  
Compaction Process ◽  
Dem Simulation ◽  
Air Voids ◽  
Superpave Gyratory Compactor

Asphalt mixture compaction is an important procedure of asphalt mixture construction and can significantly affect the performance of asphalt pavement. In this paper, an open source DEM code was applied to simulate the compaction of hot-mix asphalt (HMA) with the Superpave gyratory compactor. The asphalt mixture compaction process, air voids distribution, internal coarse aggregate structure, and the effect of CA ratio were investigated from a microscopic point of view. The analysis results show that DEM simulation is an economical and effective approach to the research of asphalt mixture compaction, and has tremendous potential for asphalt mixture design.

Predicting Field Permeability from Testing Hot-Mix Asphalt Specimens Produced by Superpave Gyratory Compactor

2005 ◽  
Vol 1929 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Kunnawee Kanitpong ◽  
Hussain Bahia ◽  
Jeffery Russell ◽  
Robert Schmitt
Keyword(s):  
Hot Mix Asphalt ◽  
Place Field ◽  
Simple Method ◽  
Air Voids ◽  
Good Relationship ◽  
Testing Procedures ◽  
Superpave Gyratory Compactor ◽  
Current Alternative ◽  
The Relationship ◽  
Better Than

This study was conducted to develop laboratory and field permeability testing procedures for design and quality control of Superpave® mixtures in Wisconsin. Sixteen mixes including fine-graded and coarse-graded mixes were evaluated. The in-place field permeability was measured by using the National Center for Asphalt Technology (NCAT) device, field cores were taken for measuring permeability in the laboratory by using the ASTM D5084 method, and laboratory compaction was used to prepare and test samples from loose mixtures recovered from the field. Two compaction procedures called Method A and Method B were used in this study to produce Superpave gyratory compacted (SGC) specimens that have thickness, air voids, and aggregate orientation similar to the field cores. Result indicates that Method B, based on the use of Ndesign gyrations for different sample sizes, can be used to produce samples that give permeability values similar to values measured for field cores. Results of this study also indicate a good relationship between field permeability (using the NCAT device) and lab permeability measured on field cores of fine-graded mixes with the amount passing No. 8 sieve (P8) higher than 45%. However, the relationship between field permeability and lab permeability measured on field cores of coarse-graded mix (P8 lower than 40%) is poor. It is concluded that the NCAT permeability device could possibly be used in the field for fine-graded mix (with P8 higher than 45%). However, to measure the field permeability of coarse-graded mix (P8 lower than 40%), there appears to be no current alternative better than taking field cores and testing them in the laboratory. For estimating permeability during mixture design, a simple method for preparing and testing permeability of SGC specimens and interpolating based on expected field density is introduced.

Evaluation of Superpave Gyratory Compaction of Hot Mix Asphalt

1998 ◽  
Vol 1638 (1) ◽  
pp. 111-119 ◽  
Author(s):  
Rajib B. Mallick ◽  
Shane Buchanan ◽  
E. Ray Brown ◽  
Mike Huner
Keyword(s):  
Specific Gravity ◽  
Correction Factor ◽  
Hot Mix Asphalt ◽  
Design System ◽  
Volumetric Properties ◽  
Superpave Gyratory Compactor ◽  
Gyratory Compaction ◽  
Back Calculation ◽  
Crushed Aggregate

The effect of restricted zone on volumetric properties of mixes consisting of all crushed, and all crushed and partially uncrushed, materials was evaluated. For a given aggregate blend, gradations below or above the restricted zone provided higher voids in mineral aggregate (VMA) than mixes through the restricted zone. Mixes with crushed aggregate provided higher VMA than mixes with partially crushed aggregate. It is recommended that further work be conducted to evaluate the effect of different types and shapes of aggregates on the volumetric properties of specimens compacted with the Superpave gyratory compactor. According to the current Superpave mix design system, the bulk specific gravity of a compacted specimen at any gyration is back calculated from the bulk specific gravity determined at Nmaximum and a correction factor determined at Nmaximum. This procedure assumes that the correction factor is constant at all gyrations. A part of this study was carried out to compare the correction factors obtained at different gyration levels during compaction of hot mix asphalt and to evaluate the change in correction factor with gyration levels. Specimens were compacted at different gyration levels, and the bulk specific gravity of each was determined at each gyration level. Bulk specific gravities at each of the gyration levels were also obtained by back calculation from bulk specific gravity at Nmaximum. The correction factor was found to decrease and become close to constant at higher gyration levels. At lower gyrations, densities were found to be greater than those obtained by back calculation. It is recommended that mixes be compacted to Ndesign for determination of design asphalt content.

Establishment of the Precision of a Rapid-Angle Measurement Device for Superpave Gyratory Compactors

2005 ◽  
Vol 1929 (1) ◽  
pp. 97-103
Author(s):  
Kevin D. Hall ◽  
Tamara Easley
Keyword(s):  
Hot Mix Asphalt ◽  
Angle Measurement ◽  
Study Data ◽  
Interlaboratory Study ◽  
Measurement Device ◽  
Superpave Gyratory Compactor ◽  
Internal Angle ◽  
Dynamic Angle

Superpave® hot-mix asphalt (HMA) specimens are compacted in the laboratory with the Superpave gyratory compactor (SGC) through pressure and an applied angle of gyration. The original compaction specification for the SGC requires the angle of gyration to be 22 ± 0.35 mrad (1.25 ± 0.02 degrees), measured externally to the compaction mold. Questions concerning the ability of different compactors to produce HMA specimens of the same mix with the same density led to the development of the dynamic angle validation (DAV) kit, which measures the angle of gyration internally (on the inside of the mold). The DAV procedure requires the use of HMA to measure the internal angle of gyration. Because of practical limitations of performing measurements with HMA and questions concerning the “proper” HMA mix to use in the measurements, a device–-the rapid-angle measurement (RAM)–-was introduced to simulate effectively the load placed on the SGC by an HMA specimen. An interlaboratory study was conducted in accordance with ASTM E691-99 to establish the precision of the internal angle measurement provided by the RAM. A total of 11 RAM units and five SGC models were included in the study. On the basis of the study data, estimates were developed of both repeatability (within lab) and reproducibility (between lab) for the RAM device for all five SGC models. It is recommended that all devices with the reported ability to measure internal angle of gyration be subjected to a similar interlaboratory study to compare devices on an equal basis.

Long-Term Field Aging of Warm-Mix and Hot-Mix Asphalt Binders

2017 ◽  
Vol 2632 (1) ◽  
pp. 140-149 ◽  
Author(s):  
Weiguang Zhang ◽  
Shihui Shen ◽  
Shenghua Wu ◽  
Louay N. Mohammad
Keyword(s):  
High Temperature ◽  
Prediction Model ◽  
Hot Mix Asphalt ◽  
Field Studies ◽  
Asphalt Binders ◽  
Climate Effect ◽  
Air Voids ◽  
Multiple Parameters ◽  
Term Field

Limited field studies have considered the aging of warm-mix asphalt (WMA) binders, especially from the perspective of long-term aging. This paper quantifies the long-term (10 to 82 months) field aging properties of WMA binders and the control hot-mix asphalt (HMA) binders and identifies the key factors associated with long-term field aging of asphalt. Asphalt binders from 23 field projects consisting of 65 HMA and WMA pavements were recovered, and high-temperature performance grade (PG) was tested. The effects of climate, month of aging, WMA technologies, and original binder high-temperature PG on field asphalt aging were analyzed. A prediction model that included multiple parameters was developed and validated. Results indicated that Evotherm WMA binder had a lower high-temperature PG than HMA binder shortly after construction, but this difference reduced with time. No statistical difference of field aging between HMA and WMA binders was observed. The climate effect on asphalt field aging was apparent within dry areas or freeze areas, whereas the aging difference between dry and freeze areas was inconclusive and requires further research. Other conclusions were that ( a) the field asphalt aging affects more of top-down longitudinal wheelpath crack than transverse crack, ( b) foaming WMA binder ages slowest of all binders considered, ( c) PG 64-XX and PG 70-XX binders aged more than PG 58-XX and PG 76-XX binders, and ( d) the prediction model had good agreement with test results and was well validated. The identified factors that affected field asphalt aging were overlay thickness, in-place air voids, effective binder content, complex shear modulus, and solar radiation.

Calculating Air Voids at Specified Number of Gyrations in Superpave Gyratory Compactor

1998 ◽  
Vol 1630 (1) ◽  
pp. 117-125 ◽  
Author(s):  
William R. Vavrik ◽  
Samuel H. Carpenter
Keyword(s):  
Quality Control ◽  
Current Method ◽  
Mixture Design ◽  
Calculation Procedure ◽  
Air Voids ◽  
Superpave Gyratory Compactor ◽  
Quality Control Testing ◽  
Field Quality ◽  
Back Calculation ◽  
Air Void

The Superpave volumetric mix design is based on compaction of mixtures to Nmax revolutions, yielding approximately 2 percent air voids, and then back-calculating the properties of the mixture at N design revolutions, which is the specified number of revolutions at which the sample should achieve 4 percent air voids. It has been shown, both in mixture design and in field quality control testing, that this back-calculation procedure is not always accurate for determining the number of gyrations that give 4 percent air voids in the compacted sample. The current back-calculation procedure is examined in this paper, and the observed inaccuracy in the current method is shown in both quality control/quality assurance (QC/QA) and the mixture design procedures. Also examined is an alternative method that has been shown to be more accurate in predicting the number of gyrations at which a mixture reaches a given air void level. This study recommends a method that gives higher accuracy in determining the number of gyrations at which a mixture reaches 4 percent air voids. A diverse group of mixtures, each having different properties, was examined, and an improved method for predicting the number of gyrations to accurately produce 4 percent air voids in the compacted mixture was determined.

scholarly journals Fatigue Performance of Recycled Hot Mix Asphalt: A Laboratory Study

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Marco Pasetto ◽  
Nicola Baldo
Keyword(s):  
Experimental Data ◽  
Hot Mix Asphalt ◽  
Design Procedure ◽  
Fatigue Performance ◽  
Dissipated Energy ◽  
Reclaimed Asphalt ◽  
Stiffness Reduction ◽  
Modified Binders ◽  
Gyratory Compaction ◽  
Experimental Data Analysis

The paper introduces and analyses the results of an experimental trial on the fatigue resistance of recycled hot mix asphalt for road pavements. Based on the gyratory compaction and the indirect tensile strength test, the mix design procedure has optimized nine different mixes, considering both conventional limestone and Reclaimed Asphalt Pavement (RAP), the latter used at different quantities, up to 40% by weight of the aggregate. A standard bitumen and two polymer modified binders were used for the production of the mixes. The fatigue study was carried out with four-point bending tests, each one performed at 20°C and 10 Hz. The empirical stiffness reduction method, along with the energy ratio approach, based on the dissipated energy concept, was adopted to elaborate the experimental data. Unaged and aged specimens were checked, to analyse the ageing effects on the fatigue performance. In comparison with the control mixes, produced only with limestone, improved fatigue performance was noticed for the mixtures prepared with RAP, especially when made with polymer modified binders, under both aged and unaged conditions. Both the approaches adopted for the experimental data analysis have outlined the same ranking of the mixes.

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