Use of Georgia Loaded Wheel Tester to Evaluate Rutting of Asphalt Samples Prepared by Superpave Gyratory Compactor

1996 ◽  
Vol 1545 (1) ◽  
pp. 161-168 ◽  
Author(s):  
Ronald Collins ◽  
Haroon Shami ◽  
James S. Lai
Keyword(s):  
Asphalt Concrete ◽  
Permanent Deformation ◽  
Testing Procedure ◽  
Test Method ◽  
Design Stage ◽  
Void Content ◽  
Test Program ◽  
Asphalt Mixes ◽  
Rutting Resistance ◽  
Superpave Gyratory Compactor

The Georgia loaded wheel tester (LWT) developed by the Georgia Department of Transportation has been used since 1985 in the laboratory during the design stage to evaluate rutting susceptibility of asphalt concrete mixtures. In the LWT testing, asphaltic concrete is subjected to an elevated temperature in a loaded wheel system under repetitive loading conditions, and the permanent deformation induced under the wheelpath is measured. This approach to assess rutting susceptibility was thought to be much more representative than the current test methods and can provide a fast and more accurate means of assessing rutting susceptibility of asphalt concrete under actual field conditions. The asphaltic beam samples used for the LWT testing are prepared by a rolling compaction machine. The new LWT developed in 1992 is described. To promote the concept of using Georgia LWT as a supplement to the Superpave Level 1 design procedure for evaluating permanent deformation of hot-mix asphalt (HMA), a test method utilizing Superpave gyratory compactor-prepared samples to evaluate the rutting resistance of HMA by the LWT was developed. The gyratory samples placed in a specially designed mold can be tested in the LWT identical to that for performing the LWT testing on the beam samples. A test program was conducted to evaluate the applicability of the testing procedure and to develop correlations between the rut depth of asphalt mixes using the beam samples and the gyratory samples. The test program used three asphalt mixes of different degrees of rutting resistance ranging from high to low rut susceptibility. Both types of samples were tested at 40°C, 50°C, and 60°C temperatures for 8,000 cycles under the standard LWT testing procedure. The rut depth results from the beam samples and the gyratory samples showed good correlations for all three mixes tested. The test results also showed a strong relationship between the rut depth values and the air void content in the mixes.

scholarly journals Study of High-Temperature Properties of Asphalt Mixtures Used for Bridge Pavement with Concrete Deck

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4238
Author(s):  
Piotr Pokorski ◽  
Piotr Radziszewski ◽  
Michał Sarnowski
Keyword(s):  
Permanent Deformation ◽  
Asphalt Mixture ◽  
Binder Content ◽  
Void Content ◽  
Concrete Bridge ◽  
Asphalt Mixes ◽  
Protective Layers ◽  
Concrete Bridge Decks ◽  
Air Void ◽  
Air Void Content

The paper presents the issue of resistance to permanent deformations of bridge pavements placed upon concrete bridge decks. In Europe, bridge asphalt pavement usually consists of a wearing course and a protective layer, which are placed over the insulation (waterproofing). Protective layers of bridge pavement are commonly constructed using low air void content asphalt mixes as this provides the suitable tightness of such layers. Due to increased binder content, asphalt mixes for bridge pavement may have reduced resistance to permanent deformations. The article presents test results of resistance to permanent deformations of asphalt mixes for the protective layers. In order to determine the composition of mixtures with low air void content and resistance to permanent deformation, an experimental design was applied using a new concept of asphalt mix composition. Twenty-seven different asphalt mixture compositions were analyzed. The mixtures varied in terms of binder content, sand content and grit ratio. Resistance to permanent deformation was tested using the laboratory uniaxial cyclic compression method (dynamic load creep). On the basis of experimental results and statistical analysis, the functions of asphalt mixture permanent deformation resistance were established. This enabled a determination of suitable mixture compositions for protective layers for concrete bridge decks.

Specimen Geometry Study for Direct Tension Test Based on Mechanical Tests and Air Void Variation in Asphalt Concrete Specimens Compacted by Superpave Gyratory Compactor

2000 ◽  
Vol 1723 (1) ◽  
pp. 125-132 ◽  
Author(s):  
Ghassan R. Chehab ◽  
Emily O’Quinn ◽  
Y. Richard Kim
Keyword(s):  
Asphalt Concrete ◽  
Tensile Testing ◽  
Complex Modulus ◽  
Specimen Geometry ◽  
Uniaxial Tensile ◽  
Void Content ◽  
Uniaxial Tensile Testing ◽  
Superpave Gyratory Compactor ◽  
Air Void ◽  
Air Void Content

Reliable materials characterization and performance prediction testing of asphalt concrete requires specimens that can be treated as statistically homogeneous and representative of the material being tested. The objective of this study was to select a proper specimen geometry that could be used for uniaxial tensile testing. Selection was based on the variation of air void content along the height of specimens cut and cored from specimens compacted by the Superpave gyratory compactor (SGC) and on the representative behavior under mechanical testing. From measurement and comparison of air void contents in cut and cored specimens, it was observed for several geometries that sections at the top and bottom and those adjacent to the mold walls have a higher air void content than do those in the middle. It is thus imperative that test specimens be cut and cored from larger-size SGC specimens. Complex modulus and constant crosshead-rate monotonic tests were conducted for four geometries—75 × 115, 75 × 150, 100 × 150, and 100 × 200 mm—to study the effect of geometry boundary conditions on responses. On the basis of graphical and statistical analysis, it was determined that there was an effect on the dynamic modulus at certain frequencies but no effect on the phase angle. Except for 75 × 115 mm, all geometries behaved similarly under the monotonic test. From these findings and other considerations, it is recommended that the 75- × 150-mm geometry, which is more conservative, and the 100- × 150-mm geometry be used for tensile testing.

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.

scholarly journals Rutting Resistance of Hot Mix Asphalt Containing Coarse Recycled Concrete Aggregates Coated with Waste Plastic Bottles

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Alireza Azarhoosh ◽  
Mehdi Koohmishi ◽  
Gholam Hossein Hamedi
Keyword(s):  
Asphalt Concrete ◽  
Cement Mortar ◽  
Permanent Deformation ◽  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Creep Tests ◽  
Stiffness Modulus ◽  
Waste Plastic ◽  
Rutting Resistance ◽  
Dynamic Creep

The use of recycled concrete aggregate (RCA) as a part of coarse aggregates in asphalt pavements confers economic and environmental benefits. Coarse RCA (CRCA) has inferior mechanical and physical properties compared to natural aggregates due to very porous and weakly adhered cement mortar. In this study, CRCA surfaces were coated with waste plastic bottles (WPB) and used at 15%, 30%, and 50% in the asphalt concrete. The Marshall, stiffness modulus, and dynamic creep tests were performed to determine the strength of hot mix asphalts against rutting. The results revealed that the use of untreated CRCA reduced the Marshall quotient and the rutting resistance of the asphalt concrete. The results of the stiffness modulus and dynamic creep tests indicated that CRCA incorporation increased permanent deformation in the tested specimens due to the reduction of asphalt concrete stiffness. However, the asphalt concrete containing treated CRCA had lower permanent deformation because WPB promotes CRCA stability by penetrating its void and reinforcing cement mortar. Furthermore, by raising the temperature, the strength of all asphalt concretes decreased against rutting, and the reduction rate was higher in the modified specimens.

scholarly journals Peculiarities of the temperature mode of operation of asphalt in airfield coatings

2018 ◽  
Vol 251 ◽  
pp. 01039
Author(s):  
A. Ramos ◽  
Eduard Kotlyarsky ◽  
Y. Vasilev ◽  
V. Talalay ◽  
I. Sarichev
Keyword(s):  
Asphalt Concrete ◽  
Climatic Conditions ◽  
Temperature Fields ◽  
Design Stage ◽  
Asphalt Mixes ◽  
Operational Conditions ◽  
Gas Jets ◽  
Concrete Layer ◽  
Mode Of Operation ◽  
The Republic

The article makes an attempt to theoretically substantiate the need to take into account the increase in the temperature of the asphalt concrete aerodrome covering when the jet jets of aircraft aircraft are re-peatedly exposed to the surface of the coating not only when calculating the thermodynamic stability of the upper layer at a jet velocity equal to or exceeding 100 m / s but also for other operational conditions. This will re-duce the risks of plastic deformation, likely jet erosion, potholes, even at the design stage and apply asphalt mixes with specified properties for the top coat. Based on the laws of transfer of thermal energy, a theory was devel-oped for calculating the temperature variation on the surface of the coating and the temperature distribution over the depth of the layer, from the effect of gas jets. The depth of heating by the gas jet of the upper asphalt-concrete layer and the factors determining this value are determined. The theoretical dependences describing the change in the temperature of the surface of the coating from the action of gas jets and the propagation of temperature fields along the thickness of the structure are revealed. The results of calculations of the temperature of the upper asphalt-concrete lay-er of the coating under the action of gas jets and in their absence in various operational and climatic conditions are presented on the example of the Republic of Peru.

An Overview of Moisture Damage in Asphalt Mixtures

2015 ◽  
Vol 73 (4) ◽  
Author(s):  
Meor Othman Hamzah ◽  
Muhammad Rafiq Kakar ◽  
Mohd Rosli Hainin
Keyword(s):  
Permanent Deformation ◽  
Asphalt Mixture ◽  
Material Design ◽  
Damage Mechanism ◽  
Moisture Damage ◽  
Short Review ◽  
Testing Procedure ◽  
Asphalt Mixtures ◽  
Test Method ◽  
Wide Range

This paper presents a short review on moisture induced damage in asphalt mixtures. Moisture induced damage is one of the most common causes of pavement distress that results in loss of strength, stripping, raveling, fatigue damage and permanent deformation. Different mechanisms have been used to explain the process of moisture damage in asphalt pavements. However, the moisture damage mechanism takes place due to the interaction of several different processes. The applicability of a single test method to evaluate moisture damage is impractical to a wide range of materials and conditions. Therefore, a new laboratory based testing procedure and analysis protocol is required, with the aim to simultaneously consider the effects of both traffic impact and moisture damage. The proper material design, efficient construction methods, reliable laboratory techniques and well planned highway surface and subsurface drainage systems may lead towards a sustainable asphalt pavement that is sufficiently durable to resist moisture damage. Although considerable advances concerning the subject have been reported, yet there is still a need to address certain issues that are actually involved in the process of asphalt mixture moisture susceptibility.

scholarly journals Assessment of Rutting Resistance and Healing for Stone Matrix Asphalt Concrete (SMAC)

2019 ◽  
Vol 11 (2) ◽  
pp. 60-69
Author(s):  
Saad Issa Sarsam ◽  
Shahed Mahmood Khalil
Keyword(s):  
Fly Ash ◽  
Asphalt Concrete ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Healing Process ◽  
Rutting Resistance ◽  
Stone Matrix Asphalt ◽  
Compressive Stresses ◽  
Asphalt Content ◽  
Stone Matrix

Stone Matrix Asphalt Concrete (SMAC) is known as tough, stable, rut-resistant mixture. In this investigation, SMAC was prepared in the laboratory using gap graded aggregates, asphalt cement, mineral filler and coal fly ash as stabilizing agent. Specimens were prepared using static compaction to the target density based on asphalt content for each case. The prepared Specimens were subjected to the 1200 repeated compressive stresses at 25 ºC under various stress levels using the pneumatic repeated load system PRLS. Specimens were subjected to microcrack healing process by external heating for 120 minutes at 60 °C, then it practices another cycle of repeated compressive stresses. The resilient modulus, permanent deformation, and rutting resistance under three levels of stress have been assessed. It was concluded that the resilient modulus Mr increases by (66, 50 and 31) %, (36, 50 and 31) % and (62, 37 and 69) %, while the permanent deformation decreases by (25, 11.4 and 25) %, (19, 31.6 and 14.5) % and (14, 9 and 8.3) % after implementation of fly ash at (OAC-0.5, OAC and OAC+0.5) % binder content under (0.068, 0.138 and 0.206) MPa of repeated compressive stress respectively. The resilient modulus increased by (17.6, 15.3, 10.5) % , (42.8, 51, 37.5) % and (18.7, 25, 23.6) %  and the permanent deformation decline by (3.52, 31.66, 6.25) % under repeated compressive stresses of (0.068, 0.138, 0.206) MPa at (25 °C) after healing for mix with (4.6, 5.1, 5.6) % asphalt content  respectively when compared with mixtures before healing.

scholarly journals Performance characteristics of the open-graded asphalt concrete filled with a special cement grout

2015 ◽  
Vol 10 (4) ◽  
pp. 316-324 ◽  
Author(s):  
Pavlina Cihackova ◽  
Petr Hyzl ◽  
Dusan Stehlik ◽  
Ondrej Dasek ◽  
Ovidijus Šernas ◽  
...  
Keyword(s):  
Asphalt Concrete ◽  
Permanent Deformation ◽  
Design Procedure ◽  
Asphalt Mixtures ◽  
Cement Grout ◽  
Skid Resistance ◽  
Asphalt Mixes ◽  
Stiffness Measurement ◽  
The Road ◽  
Laboratory Design

This paper presents a performance of the open-graded asphalt concrete filled with a special cement grout in the road structures, introduces practical examples of the usage of this technology and defines the main properties. In addition, laboratory design of asphalt mixtures filled with special grout is researched. Finally, the results obtained from various laboratory tests are evaluated. The paper contains the open-graded asphalt concrete filled with a special cement grout mix design procedure and results of stiffness measurement, low temperature properties, permanent deformation and skid resistance. Open-graded asphalt concrete filled with a special cement grout mixture is compared to the commonly used asphalt mixes. The open-graded asphalt concrete filled with a special cement grout showed better results than the commonly used asphalt mixes by the stiffness and resistance to the permanent deformation characteristics but behavior at the low temperatures is slightly problematic.

scholarly journals Research Of Asphalt Concrete Frost Resistance According To Fatigue Resistance And Stiffness Criteria

2021 ◽  
Vol 1202 (1) ◽  
pp. 012023
Author(s):  
Nauris Paulovskis
Keyword(s):  
Fatigue Life ◽  
Fatigue Resistance ◽  
Asphalt Concrete ◽  
Frost Resistance ◽  
Test Method ◽  
Bending Test ◽  
Resistance Testing ◽  
Void Content ◽  
Freezing And Thawing ◽  
Freeze Thaw

Abstract The formation of snow cover has been unsustainable in recent decades, which means that freezing and thawing are becoming more frequent in Latvia and that is one of the reasons why asphalt concrete frost resistance matters. Asphalt concrete beams were exposed to multiple freeze-thaw cycles and afterwards tested on a 4-point bending test for stiffness and fatigue resistance. Frost resistance testing for aggregates and concrete is a popular and widely described and used test method worldwide, but there is no such testing standard for asphalt concrete. This study is aimed to develop a methodology for determining the frost resistance of asphalt concrete by adapting the requirements of cement concrete standart AASHTO C666, as well as to experimentally evaluate the effect of frost resistance on the fatigue strenght and stiffness of asphalt concrete. The results show significant correlation between asphalt concrete void content and fatigue life after multiple freeze-thaw cycles and correlation between the amount of freeze-thaw cycles and asphalt concrete fatigue life.

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