scholarly journals Influence of Air Voids of Hot Mix Asphalt on Rutting within the Framework of Mechanistic-empirical Pavement Design

2013 ◽  
Vol 104 ◽  
pp. 99-108 ◽  
Author(s):  
Neethu Roy ◽  
A. Veeraragavan ◽  
J. Murali Krishnan
Keyword(s):  
Hot Mix Asphalt ◽  
Pavement Design ◽  
Air Voids

Implementing the Mechanistic–Empirical Design Guide Procedure for a Hot-Mix Asphalt–Rehabilitated Pavement in Indiana

2005 ◽  
Vol 1919 (1) ◽  
pp. 121-133 ◽  
Author(s):  
Khaled A. Galal ◽  
Ghassan R. Chehab
Keyword(s):  
Hot Mix Asphalt ◽  
Pavement Design ◽  
Design Parameters ◽  
Design Procedures ◽  
Design Concepts ◽  
Asphalt Overlay ◽  
Design Guide ◽  
Strategic Goals ◽  
And Performance

One of the Indiana Department of Transportation's (INDOT's) strategic goals is to improve its pavement design procedures. This goal can be accomplished by fully implementing the 2002 mechanistic–empirical (M-E) pavement design guide (M-E PDG) once it is approved by AASHTO. The release of the M-E PDG software has provided a unique opportunity for INDOT engineers to evaluate, calibrate, and validate the new M-E design process. A continuously reinforced concrete pavement on I-65 was rubblized and overlaid with a 13–in.-thick hot-mix asphalt overlay in 1994. The availability of the structural design, material properties, and climatic and traffic conditions, in addition to the availability of performance data, provided a unique opportunity for comparing the predicted performance of this section using the M-E procedure with the in situ performance; calibration efforts were conducted subsequently. The 1993 design of this pavement section was compared with the 2002 M-E design, and performance was predicted with the same design inputs. In addition, design levels and inputs were varied to achieve the following: ( a) assess the functionality of the M-E PDG software and the feasibility of applying M-E design concepts for structural pavement design of Indiana roadways, ( b) determine the sensitivity of the design parameters and the input levels most critical to the M-E PDG predicted distresses and their impact on the implementation strategy that would be recommended to INDOT, and ( c) evaluate the rubblization technique that was implemented on the I-65 pavement section.

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.

Multicharacteristic Performance-Related Specification for Hot-Mix Asphalt Pavement: Complete Development Process

2003 ◽  
Vol 1861 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Richard M. Weed
Keyword(s):  
Development Process ◽  
Hot Mix Asphalt ◽  
Asphalt Pavement ◽  
Performance Model ◽  
Department Of Transportation ◽  
Air Voids ◽  
Complete Development ◽  
Multiple Quality Characteristics ◽  
Engineering Mathematics ◽  
Sufficient Detail

At a time when there is great interest in developing performance-related specifications incorporating multiple quality characteristics and several highly complex approaches are under development, it is questioned whether these procedures will be capable of providing the degree of practicality and ease of application sought by most practitioners. Alternatively, it is claimed that there is a simple, straightforward procedure that is suitable for most practical purposes. The components of this procedure have been successfully applied by the New Jersey Department of Transportation over a period of many years, and it is argued that additional complexity is rarely necessary or beneficial. An example is presented illustrating how readily obtainable data can be used, first to develop the performance model and then to develop the acceptance procedure for a specification for in-place air voids, thickness, and smoothness of hot-mix asphalt pavement. The example is presented in sufficient detail to demonstrate the ease with which this procedure can be learned and applied by individuals with only a basic background in engineering mathematics.

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.

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.

Prediction of Asphalt Cement Content of Compacted Hot-Mix Asphalt Specimens Using Nuclear Gauges

1996 ◽  
Vol 1545 (1) ◽  
pp. 169-177
Author(s):  
Iyad A. Alattar ◽  
Imad L. Al-Qadi
Keyword(s):  
Moisture Content ◽  
Hot Mix Asphalt ◽  
Extraction Methods ◽  
Void Content ◽  
Study Program ◽  
Aggregate Gradation ◽  
Air Voids ◽  
Asphalt Cement ◽  
Specimen Weight ◽  
A New Technique

Determining asphalt cement (AC) content of hot-mix asphalt (HMA) for quality control/quality assurance using extraction methods is a lengthy, time-consuming, and hazardous process. A demand for a faster and safer method led to the development of different nuclear gauges capable of predicting the AC content of HMA samples. Measuring the AC content of compacted specimens by nuclear gauges is a new technique whose feasibility was evaluated. A total of 216 Marshall compacted specimens were cast and tested in an attempt to develop correction models. The study program investigated the effect of various HMA parameters on the measured AC content, including aggregate gradation and type, air void content, moisture content, AC content, and specimen weight. Specimens were prepared at two different mix design formulas using AC-30 and compacted at two different compaction efforts to investigate the effect of air voids. Specimens (1200 g each) used for calibration were prepared at 3 to 7 percent AC content, whereas specimens prepared for measurements were prepared at 4 to 6 percent. Quartzite and diabase aggregate were used as open and dense graded in prepared mixes. Three levels of moisture content in HMA were evaluated. Different calibration models were developed for different asphaltic mixtures. The evaluated nuclear gauge for measuring AC content for compacted HMA specimens produced satisfactory results when the parameters of tested and calibration parameters were the same. The study found that specimen weight is the most significant factor. Other parameters have different degrees of influence on the measured AC content. Statistical models were developed to correct for the evaluated parameters.

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.

Development of New Fatigue Model for New Zealand Dense Graded Hot Mix Asphalts

2014 ◽  
Vol 891-892 ◽  
pp. 747-752
Author(s):  
Mofreh F. Saleh
Keyword(s):  
New Zealand ◽  
Shell Model ◽  
Permanent Deformation ◽  
Flexural Modulus ◽  
Fatigue Behaviour ◽  
Binder Content ◽  
Pavement Design ◽  
Air Voids ◽  
Wide Range ◽  
Fatigue Model

The Mechanistic empirical pavement design method for flexible pavements is based on modelling certain modes of failures for different pavement materials. In the Australian and New Zealand guidelines, the mechanistic empirical pavement design is based on modelling fatigue and permanent deformation as the two major modes of failures. The Austroads guidelines use the Shell fatigue performance transfer function to model the fatigue behaviour of asphalt mixes. In this research, the fatigue behaviour of different mixes AC10, AC14 and AC20 with different types of binders 80/100 and 60/70 was thoroughly investigated. The Shell model significantly underestimated the measured fatigue life for all mixes. A wide range of properties of the examined mixes was considered; percent of air voids ranges from 1.2% to 11.4%, binder content (at optimum, ± 0.5 from optimum), and the flexural modulus ranges from 1600 to 4576 MPa. A new fatigue model was developed at the University of Canterbury. The Canterbury model was based on the bending beam fatigue results of 78 beams tested at constant strain mode at different strain levels range from 300 to 600 microstrains. The new model provides a much better matching to the measured data with no observed bias and it accounts for percentage of air voids in the total mix and the effective binder content instead of the total binder content that is currently included in the Shell Model.

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