MULTISCALE VISCOELASTIC−VISCOPLASTIC MODEL FOR THE PREDICTION OF PERMANENT DEFORMATION IN FLEXIBLE PAVEMENTS

2012 ◽  
Vol 10 (6) ◽  
pp. 615-634 ◽  
Author(s):  
Elisabeth Aigner ◽  
Roman Lackner ◽  
Josef Eberhardsteiner
Keyword(s):  
Permanent Deformation ◽  
Flexible Pavements ◽  
Viscoplastic Model

Determination of residual life in flexible pavements

1996 ◽  
Vol 23 (5) ◽  
pp. 1012-1024 ◽  
Author(s):  
Moshe Livneh
Keyword(s):  
Residual Life ◽  
Permanent Deformation ◽  
Flexible Pavements ◽  
Service Level ◽  
Rehabilitation Service ◽  
Basic Question ◽  
Pavement Rehabilitation ◽  
Structural Deterioration ◽  
Visual Testing ◽  
Life Parameter

In the field of pavement rehabilitation design, one finds a prominent absence of uniformity in the principles of calculation, a lack of clarity as to the testing methods, and a confusion of basic physical concepts. An example of this situation is the residual life of the pavement structure, which constitutes an important measure in the calculation of pavement bearing capacity. The basic question of how to establish such a parameter in practice is discussed in this paper by examining the relationships between the residual life parameter and the pavement surface state, the pavement structural state, the pavement functional state, and the effects of asphalt fatigue or the total structural deterioration on the residual life-span. Finally, this paper suggests a method for including the residual life parameter within the design process of flexible pavement rehabilitation. Key words: cracking, damages, deflection, permanent deformation, evaluation, fatigue, flexible pavements, overlay, rehabilitation, service level, visual testing.

scholarly journals Methodology development and local calibration of MEPDG permanent deformation models for Ontario's flexible pavements.

2021 ◽  
Author(s):  
Afzal Waseem
Keyword(s):  
Permanent Deformation ◽  
Flexible Pavements ◽  
Field Evaluation ◽  
Pavement Performance ◽  
Layer By Layer ◽  
Local Calibration ◽  
Methodology Development ◽  
Design Guide ◽  
Level 3 ◽  
Deformation Models

The AASHTO-supported interim Mechanistic-Empirical Pavement Design Guide (MEPDG) was published in 2008 for trial use. However, local calibration of the empirical distress models in the design guide has been an essential exercise for any transportation agency before it formally adopts the MEPDG for practical design use. Nevertheless, a universally agreed upon local calibration methodology using historical pavement performance data from field evaluation has not been available. This research focuses on permanent deformation or rutting models in MEPDG and presents a layer-by-layer longitudinal local calibration process at the DARWin-METM platform coupled with Excel Macros. Using the best input data available, many of Level 3 accuracy, the study performs local calibration for 10 reconstructed and 19 rehabilitated flexible pavement sections. Further, this thesis statistically evaluated the level-3 pre-overlay rut value for rehabilitated flexible pavements in Ontario. A comparison of the longitudinal calibration and pooled local calibration demonstrated the importance of the longitudinal calibration in the quantification of uncertainties involved in local calibration.

scholarly journals Methodology development and local calibration of MEPDG permanent deformation models for Ontario's flexible pavements.

2021 ◽  
Author(s):  
Afzal Waseem
Keyword(s):  
Permanent Deformation ◽  
Flexible Pavements ◽  
Field Evaluation ◽  
Pavement Performance ◽  
Layer By Layer ◽  
Local Calibration ◽  
Methodology Development ◽  
Design Guide ◽  
Level 3 ◽  
Deformation Models

The AASHTO-supported interim Mechanistic-Empirical Pavement Design Guide (MEPDG) was published in 2008 for trial use. However, local calibration of the empirical distress models in the design guide has been an essential exercise for any transportation agency before it formally adopts the MEPDG for practical design use. Nevertheless, a universally agreed upon local calibration methodology using historical pavement performance data from field evaluation has not been available. This research focuses on permanent deformation or rutting models in MEPDG and presents a layer-by-layer longitudinal local calibration process at the DARWin-METM platform coupled with Excel Macros. Using the best input data available, many of Level 3 accuracy, the study performs local calibration for 10 reconstructed and 19 rehabilitated flexible pavement sections. Further, this thesis statistically evaluated the level-3 pre-overlay rut value for rehabilitated flexible pavements in Ontario. A comparison of the longitudinal calibration and pooled local calibration demonstrated the importance of the longitudinal calibration in the quantification of uncertainties involved in local calibration.

Accelerated Pavement Testing to Evaluate the Reinforcement Effect of Geogrids in Flexible Pavements

2020 ◽  
Vol 2674 (10) ◽  
pp. 134-145
Author(s):  
Bingye Han ◽  
Pawel Polaczyk ◽  
Hongren Gong ◽  
Rong Ma ◽  
Yuetan Ma ◽  
...  
Keyword(s):  
Permanent Deformation ◽  
Flexible Pavements ◽  
Performance Testing ◽  
Base Layer ◽  
Reinforcement Effect ◽  
Accelerated Pavement Testing ◽  
Forensic Evaluations ◽  
Base Course ◽  
Pavement Testing ◽  
Response Testing

This study presents an accelerated pavement testing (APT) to evaluate the reinforcement effect of geogrids in flexible pavements. A full-scale conventional three-layer flexible pavement structure was constructed, and was divided into one unreinforced section and two reinforced sections with base reinforced by geogrids placed at different depth of base course. The testing program was divided into three parts: performance testing, response testing, and forensic evaluations. The performance testing recorded the development of surface permanent deformation with the number of loadings. The falling weight deflectometer (FWD) was employed to investigate deflections and moduli of flexible pavements in the response testing. The excavation of pavements was to further analyze reinforcement mechanisms. Test results demonstrated the benefits of incorporating geogrids in base course in reducing the permanent deformation and improving the modulus of base course. Compared with the unreinforced section, accumulated permanent deformations in the two reinforced sections decreased significantly, with a drop of 13%–37%, and the back-calculated moduli of the reinforced base increased by 58%–78% after APT. It was possible that sufficient permanent deformation was needed for mobilizing geogrids to constrain lateral movements of granular particles, to increase the overall structural behavior of the reinforced base course, and to improve the stress distribution on the subgrade. These interaction mechanisms were also confirmed in the pavement trench. For a pavement system consisting of a thin surface and base layer, the proper placement position of geogrids was at the base–subgrade interface for this test and loading arrangement.

scholarly journals Performance-Based Asphalt Mix and Pavement Design

2013 ◽  
Vol 2 (1) ◽  
pp. 21-38 ◽  
Author(s):  
Ronald Blab
Keyword(s):  
Low Temperature ◽  
Deformation Behavior ◽  
Elevated Temperatures ◽  
Permanent Deformation ◽  
Flexible Pavements ◽  
Test Methods ◽  
Service Performance ◽  
Triaxial Tests ◽  
Uniaxial Tensile ◽  
Induced Stresses

Abstract Prediction and optimization of in-service performance of road pavements during their live time is one of the main objectives of pavement research these days. For flexible pavements the key performance characteristics are fatigue and low-temperature, as well as permanent deformation behavior at elevated temperatures. The problem facing pavement designers is the need to fully characterize the complex thermo-rheological properties of hot mix asphalt (HMA) over a wide temperature range on the one hand, while on the other also providing a realistic simulation of the traffic- and climate-induced stresses to which pavements are exposed over their design lives of 20 to 30 years. Where heavily trafficked roads are concerned, there is therefore an urgent need for more comprehensive test methods combined with better numerical forecast procedures to improve the economics and extend the service lives of flexible pavements under repair and maintenance programs. This papers therefore focus on performance-based test methods on the basis of existing European standards that address effective mechanical characteristics of bituminous materials and which may be introduced into national requirements within the framework of European HMA specifications. These test methods comprise low temperature tests, i.e. the tensile stress restrained specimen test or the uniaxial tensile strength test, stiffness and fatigue tests, i.e. the four point bending beam test or the uniaxial tension compression test, as well as methods to determine permanent deformation behavior by means of dynamic triaxial tests. These tests are used for the performance-based mix design and subsequently implemented in numerical pavement models for a reliable prediction of in-service performance, which, in combination with performance-based tests, enables a simulation of load-induced stresses and mechanogenic effects on the road structure and thus improved forecasts of the in-service performance of flexible pavements over their entire service lives.

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