Fatigue Performance Evaluation of WesTrack Asphalt Mixtures Using Viscoelastic Continuum Damage Approach

Fatigue Performance Evaluation of WesTrack Asphalt Mixtures Using Viscoelastic Continuum Damage Approach PDF Author: Y. Richard Kim
Publisher:
ISBN:
Category : Asphalt concrete
Languages : en
Pages : 258

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Book Description
Introduction -- Objectives and summary -- Theoretical background -- Test methods -- Materials and specimen fabrication -- Uniaxial testing -- Determination of viscoelastic properties from IDT test -- Development of a simple performance test and validation -- Conclusions and recommendations -- Implementation and technology transfer plan -- References -- Appendices.

Fatigue Performance Evaluation of WesTrack Asphalt Mixtures Using Viscoelastic Continuum Damage Approach

Fatigue Performance Evaluation of WesTrack Asphalt Mixtures Using Viscoelastic Continuum Damage Approach PDF Author: Y. Richard Kim
Publisher:
ISBN:
Category : Asphalt concrete
Languages : en
Pages : 258

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Book Description
Introduction -- Objectives and summary -- Theoretical background -- Test methods -- Materials and specimen fabrication -- Uniaxial testing -- Determination of viscoelastic properties from IDT test -- Development of a simple performance test and validation -- Conclusions and recommendations -- Implementation and technology transfer plan -- References -- Appendices.

Fatigue Performance Evaluation of WesTrack Asphalt Mixtures Based on Viscoelastic Analysis of Indirect Tensile Test

Fatigue Performance Evaluation of WesTrack Asphalt Mixtures Based on Viscoelastic Analysis of Indirect Tensile Test PDF Author: Hafiang Wen
Publisher:
ISBN:
Category :
Languages : en
Pages : 146

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Book Description
Keywords: Indirect tensile test, Simple performance test, Asphalt concrete, WesTrack, Viscoelastic.

Fatigue Performance Evaluation of WesTrack Asphalt Mixtures Based on Viscoelastic Analysis of Indirect Tensile Test

Fatigue Performance Evaluation of WesTrack Asphalt Mixtures Based on Viscoelastic Analysis of Indirect Tensile Test PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
This dissertation presents the viscoelastic characterization of asphalt concrete in indirect tensile testing and the development of a simple performance test for fatigue cracking. The analytical solutions to calculate creep compliance and center strain from displacements measured on the specimen surface were developed based upon the theory of viscoelasticity. These developments were verified by 3-D finite element viscoelastic analysis and tests. A simple performance test was developed based on these solutions and work potential theory. To evaluate its validity, the indirect tensile tests were performed on WesTrack asphalt mixtures varying aggregate gradations, asphalt contents, and air void contents. Fracture energy obtained from indirect tensile strength testing and creep testing was highly correlated with field performance of these mixtures at WesTrack. A combination of indirect tensile creep and strength testing was proposed as a simple performance test for fatigue cracking. Recommendations for expanding the applicability of the simple performance test developed are provided.

Fatigue Evaluation of Asphalt Mixtures Using Dissipated Energy and Viscoelastic Continuum Damage Approaches

Fatigue Evaluation of Asphalt Mixtures Using Dissipated Energy and Viscoelastic Continuum Damage Approaches PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 27

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Book Description


Fatigue Performance Prediction of North Carolina Mixtures Using Simplified Viscoelastic Continuum Damage Model

Fatigue Performance Prediction of North Carolina Mixtures Using Simplified Viscoelastic Continuum Damage Model PDF Author: Tian Hou
Publisher:
ISBN:
Category :
Languages : en
Pages : 117

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Book Description
Keywords: viscoelastic continuum damage, simplified model, fatigue, asphalt.

Fatigue Performance Prediction of North Carolina Mixtures Using Simplified Viscoelastic Continuum Damage Model

Fatigue Performance Prediction of North Carolina Mixtures Using Simplified Viscoelastic Continuum Damage Model PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Fatigue performance modeling is one the major topics in asphalt concrete modeling work. Currently the only standard fatigue test available for asphalt concrete mixtures is the flexural bending fatigue test, AASHTO T-321. There are several issues associated with flexural fatigue testing, the most important of which are the stress state is not uniform but varies over the depth of the specimen and equipment for fabricating beam specimens is not widely available. Viscoelastic continuum damage (VECD) fatigue testing is a promising alternative to flexural fatigue testing. Different researchers have successfully applied the VECD model to asphalt concrete mixtures using constant crosshead rate direct tension test. However, due to the load level limitation of the new coming Asphalt Mixture Performance Tester (AMPT) testing equipment, there is an immediate need to develop a model that can characterize fatigue performance quickly using cyclic test data. In this study, a simplified viscoelastic continuum damage model developed at NCSU is applied to various North Carolina mixtures, which are used in the NCDOT HWY-2007-7 MEPDG local calibration project. It is shown that the simplified VECD model can predict fatigue tests fairly accurately under various temperature conditions and strain levels. It is also shown that the model can be further utilized to simulate both the strain controlled direct tension fatigue test and the traditional beam fatigue test. In this thesis, simulation results are presented. Conclusions regarding the applicability of the new model are advanced as well as suggestions for further work.

Development of a Fast and Cost-effective Asphalt Mixture Fatigue Test System

Development of a Fast and Cost-effective Asphalt Mixture Fatigue Test System PDF Author: Aksel Seitllari
Publisher:
ISBN:
Category : Asphalt
Languages : en
Pages : 151

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Book Description
Fatigue cracking is one of the critical distress modes in asphalt pavements. Accurate prediction and evaluation of fatigue performance are crucial to extending the service life of asphalt mixtures. Naturally, laboratory testing methods for fatigue characterization are time-consuming and require sophisticated procedures. Any effort to improve the speed and quality of the information gained from laboratory fatigue tests is valuable. This research work presents the results of a study investigating the possibility of implementing a new approach to characterize asphalt mixture fatigue behavior. This new approach includes cyclic tests run on cylindrical asphalt specimens in three-point beam mode (herein referred to as three-point bending cylinder (3PBC) geometry). Timoshenko beam theory along with the viscoelastic continuum damage (VECD) theory was implemented to model the mechanical response of the specimens. An excellent correlation between the results of 3PBC tests and uniaxial push-pull fatigue tests were observed. The 3PBC setup possesses the most advantages of uniaxial push-pull tests and includes more advantages such as not requiring a saw to cut the ends of the sample, not requiring gluing operation (and the gluing jig) and the possibility of estimating Poisson's ratio from the data. The proposed 3PBC approach was evaluated through laboratory tests conducted on various asphalt mixtures with varying binder types, mix components, and volumetric properties. The approach proposed herein was validated through finite element analysis. In addition, ruggedness evaluation of the 3PBC testing approach through varying factors and their levels were investigated and presented.

Long and Deep Tunnels

Long and Deep Tunnels PDF Author: Vittorio Guglielmetti
Publisher: CRC Press
ISBN: 0415558549
Category : Technology & Engineering
Languages : en
Pages : 1336

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Book Description
The design and construction of “long and deep” tunnels, i.e. tunnels under mountains, characterised by either considerable length and/or overburden, represent a considerable challenge. The scope of this book is not to instruct how to design and construct such tunnels but to share a method to identify the potential hazards related to the process of designing and constructing long and deep tunnels, to produce a relevant comprehensive analysis and listing, to quantify the probability and consequences, and to design proper mitigation measures and countermeasures. The design, developed using probabilistic methods, is verified during execution by means of the so called Plan for Advance of the Tunnel (PAT) method, which allows adapting the design and control parameters of the future stretches of the tunnel to the results of the stretches already finished, using the monitoring data base. Numerous criteria are given to identify the key parameters, necessary for the PAT procedure. Best practices of excavation management with the help of real time monitoring and control are also provided. Furthermore cost and time evaluation systems are analysed. Finally, contractual aspects related to construction by contract are investigated, for best development and application of models more appropriate for tunnelling-construction contracts. The work will be of interest to practising engineers, designers, consultants and students in mining, underground, tunnelling, transportation and construction engineering, as well as to foundation and geological engineers, urban planners/developers and architects.

Development of a Simplified Fatigue Test and Analysis Procedure Using a Viscoelastic, Continuum Damage Model and Its Implementation to WesTrack Mixtures

Development of a Simplified Fatigue Test and Analysis Procedure Using a Viscoelastic, Continuum Damage Model and Its Implementation to WesTrack Mixtures PDF Author: Jo Sias Daniel
Publisher:
ISBN:
Category : Asphalt concrete
Languages : en
Pages : 416

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Book Description


Viscoelastic Analysis and Fatigue Characterization of Bituminous Materials in Two Length Scales Under the Influene of Aging

Viscoelastic Analysis and Fatigue Characterization of Bituminous Materials in Two Length Scales Under the Influene of Aging PDF Author: Santosh Reddy Kommidi
Publisher:
ISBN:
Category :
Languages : en
Pages : 88

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Book Description
Fatigue cracking in asphalt concrete (AC) is of immense importance to pavement design and analysis because it is one of the most important forms of distress that can lead to structural failure in pavement. Once started, these types of cracks can be combined with other environmental factors leading to detrimental effects such as faster rates of pavement deterioration and shortened pavement life and functionality. Currently AASHTO TP101, also known as linear amplitude sweep (LAS) specification, is being widely used to evaluate the ability of an asphalt binder to resist fatigue. The LAS method, although mechanistic in its approach, has certain drawbacks. First, the test is performed on an aged 2-mm thick binder sample, which in reality may never exist in the AC where there is a varying non-uniform thickness of the binder across the components of the AC. Secondly, the test methodology predicts an increased fatigue resistance at lower strain levels of load when the binder ages. This is in contrast to the general belief among researchers that aging is one of the primary contributors to the acceleration of pavement cracking. This study aims to evaluate fatigue resistance in a more realistic approach that is more likely to exist in AC by incorporating sand asphalt mixtures. First, the linear viscoelastic properties of binder and sand asphalt mixture samples were evaluated to obtain the material properties under the influence of aging. Later, the fatigue tests on the sand asphalt mixture were investigated to understand the influence of a thin film of binder on the fatigue resistance. It was observed that based energy dissipation criterion for the binder evaluated a reasonable estimate for fatigue damage at relatively lower temperatures, but was limited to capture the influence of aging. Moreover, it was observed that fatigue testing on a binder at an intermediate temperature of 25 °C could cause edge effects to dominate as seen in the plateau regime for the phase angle in the time sweep tests. In order to overcome the edge effects in the binder LAS tests, the sand asphalt mixture testing was used for analyzing the binder fatigue resistance. Sand asphalt mixture testing could capture the microcracking and macrocracking phases more distinctively when compared to binder testing. In the case of pressure aging vessel (PAV) aged samples, it was observed that the macrocracking phase disappeared and was replaced by sudden changes in the material properties, indicating that the PAV aged mixture was more susceptible to fatigue cracking. By using the simplified viscoelastic continuum damage approach, the fatigue resistance of the binder and sand asphalt mixture was evaluated. The sand asphalt mixture testing was better to capture the influence of aging and changes in the microstructure during fatigue in comparison to binder fatigue tests..