scholarly journals A GPR-Based Pavement Density Profiler: Operating Principles and Applications

2021 ◽  
Vol 13 (13) ◽  
pp. 2613
Author(s):  
Nectaria Diamanti ◽  
A. Peter Annan ◽  
Steven R. Jackson ◽  
Dylan Klazinga
Keyword(s):  
Asphalt Pavement ◽  
Wave Impedance ◽  
Asphalt Mixtures ◽  
Void Content ◽  
Air Voids ◽  
New Instrument ◽  
Pavement Engineering ◽  
And Performance ◽  
Air Void ◽  
Air Void Content

Density is one of the most important parameters in the construction of asphalt mixtures and pavement engineering. When a mixture is properly designed and compacted, it will contain enough air voids to prevent plastic deformation but will have low enough air void content to prevent water ingress and moisture damage. By mapping asphalt pavement density, areas with air void content outside of the acceptable range can be identified to predict its future life and performance. We describe a new instrument, the pavement density profiler (PDP) that has evolved from many years of making measurements of asphalt pavement properties. This instrument measures the electromagnetic (EM) wave impedance to infer the asphalt pavement density (or air void content) locally and over profiles.

Use of Mechanistic Models to Investigate Fatigue Performance of Asphalt Mixtures

2015 ◽  
Vol 2507 (1) ◽  
pp. 108-119 ◽  
Author(s):  
Jong-Sub Lee ◽  
Nelson Gibson ◽  
Y. Richard Kim
Keyword(s):  
Damage Model ◽  
Asphalt Mixtures ◽  
Fatigue Performance ◽  
Void Content ◽  
Continuum Damage ◽  
Direct Tension ◽  
Air Voids ◽  
Viscoelastic Continuum Damage ◽  
Air Void ◽  
Air Void Content

Effects of design air void contents, design voids in mineral aggregate (VMA), and in-place air voids on the fatigue performance of asphalt mixtures were investigated with mechanistic analyses based on the viscoelastic continuum damage (VECD) analyses and the mechanistic–empirical pavement analysis using the AASHTOWare Pavement ME Design program. The VECD analyses included the simplified viscoelastic continuum damage model at the material level and two structural models: ( a) layered viscoelastic analysis and ( b) layered viscoelastic pavement analysis for critical distresses. The mix design of a 2013 accelerated loading facility test lane was selected to develop the volumetric mix designs with the design air voids of 3%, 4%, and 5%, design VMAs of 13%, 14%, and 15%, and in-place air void contents of 5%, 7%, and 9% with the Bailey method. Dynamic modulus and direct tension cyclic fatigue tests were performed in accordance with the AASHTO TP 107 procedure. The test results showed that the linear viscoelastic property was affected by the design VMA, design air void content, and in-place air void content in order of sensitivity. Also, the damage states at failure determined from the damage characteristic curves and the mechanistic fatigue predictions had consistent trends as observed for the design VMA, in-place air void, and design air void content in rank of sensitivity. Finally, the design VMA, in-place air void, and design air void parameters were found to be sensitive in the mechanistic analyses, whereas the parameter that was most sensitive in the pavement mechanistic–empirical analysis was the in-place air void content.

scholarly journals Asphalt Layer Density and Air Voids Content: GPR and Laboratory Testing Data Reliance

2020 ◽  
Vol 15 (3) ◽  
pp. 93-110
Author(s):  
Andrius Baltrušaitis ◽  
Audrius Vaitkus ◽  
Juris Smirnovs
Keyword(s):  
Asphalt Pavement ◽  
Relative Dielectric Permittivity ◽  
Void Content ◽  
Air Voids ◽  
The Road ◽  
Layer Density ◽  
Road Pavement ◽  
Ground Penetrating ◽  
Air Void ◽  
Air Void Content

The assurance of asphalt pavement layer compaction, expressed by ratio between field and laboratory bulk density and air voids content, is one of the main criteria of the durability of asphalt road pavement. Destructive measures should be applied and cores should be taken from the asphalt pavement seeking to determine the representative compaction level of the constructed asphalt layers. New methods are constantly being sought for fast, non-destructive and accurate asphalt layer density and air void determination on road. Ground Penetrating Radar (GPR) can allow determining the qualitative characteristics of asphalt pavement across the entire length of the road without causing damage to the road structure. Relative dielectric permittivity, usually called dielectric value or constant, is the leading property used in GPR applications on road pavement surveys. This article presents GPR measurement results from asphalt base and binder layers of four test sections. GPR measurements were conducted immediately after the end of asphalt layer compaction process. Test points on each layer were selected and density, air void content were determined by drilling cores and testing them in the laboratory. To estimate asphalt layer density and air void content, GPR data were analysed using different existing mathematical models. To justify the reliability of the data measured by GPR, results were checked by comparing them with the results measured directly on cores taken from the asphalt pavement layers.

Moisture Sensitivity of Asphalt Mixtures using Cycling Pore Pressure Conditioning

2019 ◽  
Vol 2673 (2) ◽  
pp. 294-303 ◽  
Author(s):  
Pajtim Sulejmani ◽  
Safwat Said ◽  
Sven Agardh ◽  
Abubeker Ahmed
Keyword(s):  
Pore Pressure ◽  
Complex Modulus ◽  
Moisture Damage ◽  
Climate Impacts ◽  
Binder Content ◽  
Asphalt Mixtures ◽  
Void Content ◽  
Premature Failure ◽  
Air Void ◽  
Air Void Content

One of the major causes of premature failure in asphalt pavements is moisture damage. Asphalt mixtures designed without considering climate impacts may suffer from durability problems caused by movement of water inside the asphalt mixture. Rolling traffic over wet pavement builds up pore pressure in the mixture, which will consequently accelerate deterioration. The objective of the study was to assess the moisture damage to asphalt concrete mixtures by means of complex modulus testing of dry and moisture-conditioned asphalt specimens with various mixture compositions. The asphalt mixtures were conditioned with the Moisture Induced Sensitivity Tester (MIST), which aims to replicate pore pressure in field conditions. The results showed a decline in stiffness modulus and a reduction in elastic properties after MIST conditioning. In addition, the results indicated that binder content and air void content had a significant influence on the reduction in stiffness. To capture the relationship between air void content, binder content, and the reduction in stiffness, a relationship was developed and validated with measurements on cores extracted in the field.

scholarly journals Influences by Air Voids on the Low-Temperature Cracking Property of Dense-Graded Asphalt Concrete Based on Micromechanical Modeling

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Tao Ma ◽  
Yao Zhang ◽  
Hao Wang ◽  
Xiaoming Huang ◽  
Yongli Zhao
Keyword(s):  
Low Temperature ◽  
Asphalt Concrete ◽  
Three Dimensions ◽  
Micromechanical Modeling ◽  
Void Content ◽  
Cracking Behavior ◽  
Air Voids ◽  
Low Temperature Cracking ◽  
Air Void ◽  
Air Void Content

This study characterized the impacts of air voids on the low-temperature cracking behavior of dense-graded asphalt concrete. Virtual low-temperature bending beam test for dense-graded asphalt concrete was built and executed by discrete element method and PFC3D (particle flow code in three dimensions). Virtual tests were applied to analyze the impacts by content, distribution, and size of air voids on the low-temperature properties of dense-graded asphalt concrete. The results revealed that higher air void content results in worse low-temperature property of dense-graded asphalt concrete, especially when the air void content exceeds the designed air content; even with the same designed air void content, different distributing condition of air voids within asphalt concrete leads to different low-temperature properties of asphalt concrete, especially when the air void content in the central-lower part of testing sample varies. Bigger size of single air void which tends to form interconnected air voids within asphalt concrete has more harmful impacts on the low-temperature properties of asphalt concrete. Thus, to achieve satisfied low-temperature properties of dense-graded asphalt concrete, it is critical to ensure the designed air void content, improve the distribution of air voids, and reduce the interconnected air voids for dense-graded asphalt concrete.

scholarly journals Influence of Air Void Content on Moisture Damage Susceptibility of Asphalt Mixtures

2014 ◽  
Vol 2446 (1) ◽  
pp. 8-16 ◽  
Author(s):  
A. Varveri ◽  
S. Avgerinopoulos ◽  
C. Kasbergen ◽  
A. Scarpas ◽  
A. Collop
Keyword(s):  
Moisture Damage ◽  
Asphalt Mixtures ◽  
Void Content ◽  
Damage Susceptibility ◽  
Air Void ◽  
Air Void Content

Effects of Water Saturation Level on Resistance of Compacted Hot-Mix Asphalt Samples to Moisture-Induced Damage

2000 ◽  
Vol 1723 (1) ◽  
pp. 97-106 ◽  
Author(s):  
Bouzid Choubane ◽  
Gale C. Page ◽  
James A. Musselman
Keyword(s):  
Water Saturation ◽  
Potential Interaction ◽  
Void Content ◽  
Test Results ◽  
Moisture Susceptibility ◽  
Air Voids ◽  
Florida Department ◽  
Stripping Potential ◽  
Air Void ◽  
Air Void Content

The Florida Department of Transportation (FDOT) initiated monitoring of its first Superpave section on I-75 in Columbia County for stripping potential using AASHTO T 283, which specifies that all conditioned test samples be saturated to between 55 and 80 percent based on 7 ± 1 percent air voids. A fairly large saturation range is allowed because it was thought that mixtures may have different percentages of permeable air voids. However, the potential interaction between air void content and the level of saturation has not been fully investigated. It is also not clear whether test results from samples saturated to 55 percent are comparable with those of the same mixture saturated to 80 percent for a similar air void content. Therefore, although FDOT adopted AASHTO T 283, it also initiated a parallel study on the effects of different degrees of saturation on moisture damage. Findings are reported of both the ongoing monitoring of the I-75 project for potential stripping and the investigation of the effects of different levels of saturation on moisture susceptibility test results as determined using AASHTO T 283.

scholarly journals Investigation of Acoustic Properties of Poroelastic Asphalt Mixtures in Laboratory and Field Conditions

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2649
Author(s):  
Wladyslaw Gardziejczyk ◽  
Piotr Jaskula ◽  
Jerzy A. Ejsmont ◽  
Marek Motylewicz ◽  
Marcin Stienss ◽  
...  
Keyword(s):  
Particle Size ◽  
Absorption Coefficient ◽  
Sound Absorption ◽  
Asphalt Mixtures ◽  
Acoustic Properties ◽  
Sound Absorption Coefficient ◽  
Void Content ◽  
Laboratory Conditions ◽  
Air Void ◽  
Air Void Content

Measures for the improvement of acoustic conditions in the vicinity of roads include the construction of pavement structures with low-noise surfaces with optimal macrotexture and the highest possible sound absorption coefficient. Laboratory evaluation of acoustic properties of a designed asphalt mixture before its placement in the pavement is a good solution. Currently, the most popular method for the determination of the sound absorption coefficient of various construction materials under laboratory conditions is the Kundt’s tube test. Sound absorption coefficient can also be assessed based on field and laboratory measurements performed using a Spectronics ACUPAVE System. Other parameters characterising the acoustic properties of road pavement courses include air void content and water drainability or permeability. The article presents an analysis of results of sound absorption coefficient obtained using a Spectronics ACUPAVE System and water drainability and permeability of poroelastic mixtures obtained both in laboratory and on test sections, in relation to air void content and grading of the mixtures. It was established that poroelastic mixtures containing an aggregate of maximum particle size of 5 mm are characterised by better acoustic properties than mixtures with a maximum aggregate particle size of 8 mm. Changes of crumb rubber aggregate grading and bitumen type (within the tested range of values) as well as the addition of lime have shown no evident influence on the sound absorption coefficient. Noise level values at the speed of 30 km/h according to the CPX method were measured as well. Relationships between sound absorption coefficient, water drainability/permeability, and air void content were determined. The performed analyses confirmed that Spectronics ACUPAVE System may be applied for evaluation of acoustic properties of asphalt mixtures in laboratory conditions, but further research is needed to reduce the uncertainty of the results.

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