Measurements of Surface Energy and Its Relationship to Moisture Damage

Measurements of Surface Energy and Its Relationship to Moisture Damage

Author:

Publisher:

Published: 2005

Total Pages: 174

ISBN-13:

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Moisture damage in asphalt mixes can be defined as loss of strength and durability due to the presence of moisture at the binder-aggregate interface (adhesive failure) or within the binder (cohesive failure). This research focuses on the evaluation of the susceptibility of aggregates and asphalts to moisture damage through understanding the micro-mechanisms that influence adhesive bond between aggregates and asphalt and the cohesive strength and durability of the binder. Moisture damage susceptibility is assessed using surface energy measurements and Dynamic Mechanical Analysis (DMA). Surface energy is defined as the energy needed to create a new unit surface area of material in vacuum condition. Surface energy measurements are used to compute the adhesive bond strength between the aggregates and asphalt and cohesive bond strength in the binder. DMA testing evaluates the rate of damage accumulation in asphalt binders and mastics. The DMA apparatus applies a cyclic, torsional strain-controlled loading to cylindrical asphalt mastics until failure. DMA results are analyzed using continuum damage mechanics that focus on separating the energy expended in damaging the material from that associated with viscoelastic deformation. This report presents a new approach developed to analyze DMA results and calculate the rate of damage. The developed approach is used to evaluate six asphalt mixtures that have performed either well or poorly in the field. The resistance of the field mixes to moisture damage is shown to be related to the calculations of bind energies and the accumulated damage in DMA.


Application of Surface Energy Measurements to Evaluate Moisture Susceptibility of Asphalt and Aggregates

Application of Surface Energy Measurements to Evaluate Moisture Susceptibility of Asphalt and Aggregates

Author: Corey James Zollinger

Publisher:

Published: 2005

Total Pages:

ISBN-13:

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Moisture damage in asphalt mixes can be defined as loss of strength and durability due to the presence of moisture at the binder-aggregate interface (adhesive failure) or within the binder (cohesive failure). This research focuses on the evaluation of the susceptibility of aggregates and asphalts to moisture damage through understanding the micro-mechanisms that influence the adhesive bond between aggregates and asphalt and the cohesive strength and durability of the binder. Moisture damage susceptibility is assessed using surface energy measurements and dynamic mechanical analysis (DMA). Surface energy is defined as the energy needed to create a new unit surface area of material in vacuum condition. Surface energy measurements are used to compute the adhesive bond strength between the aggregates and asphalt and cohesive bond strength in the binder. DMA testing is used to evaluate the rate of damage accumulation in asphalt binders and mastics. The DMA applies a cyclic, torsional strain controlled loading to cylindrical asphalt mastics until failure. The DMA results are analyzed using continuum damage mechanics that focuses on separating the energy expended in damaging the material from that associated with viscoelastic deformation. A new approach is developed to analyze the DMA results and calculate the rate of damage. The developed approach is used to evaluate six asphalt mixtures which have performed either well or poorly in the field. The resistance of the field mixes to moisture damage is shown to be related to the calculations of bind energies and the accumulated damage in the DMA.


Electrical Measuring Instruments and Measurements

Electrical Measuring Instruments and Measurements

Author: S.C. Bhargava

Publisher: CRC Press

Published: 2012-12-27

Total Pages: 218

ISBN-13: 0415621356

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This book, written for the benefit of engineering students and practicing engineers alike, is the culmination of the author's four decades of experience related to the subject of electrical measurements, comprising nearly 30 years of experimental research and more than 15 years of teaching at several engineering institutions. The unique feature of this book, apart from covering the syllabi of various universities, is the style of presentation of all important aspects and features of electrical measurements, with neatly and clearly drawn figures, diagrams and colour and b/w photos that illustrate details of instruments among other things, making the text easy to follow and comprehend. Enhancing the chapters are interspersed explanatory comments and, where necessary, footnotes to help better understanding of the chapter contents. Also, each chapter begins with a "recall" to link the subject matter with the related science or phenomenon and fundamental background. The first few chapters of the book comprise "Units, Dimensions and Standards"; "Electricity, Magnetism and Electromagnetism" and "Network Analysis". These topics form the basics of electrical measurements and provide a better understanding of the main topics discussed in later chapters. The last two chapters represent valuable assets of the book, and relate to (a) "Magnetic Measurements", describing many unique features not easily available elsewhere, a good study of which is essential for the design and development of most electric equipment – from motors to transformers and alternators, and (b) "Measurement of Non-electrical Quantities", dealing extensively with the measuring techniques of a number of variables that constitute an important requirement of engineering measurement practices. The book is supplemented by ten appendices covering various aspects dealing with the art and science of electrical measurement and of relevance to some of the topics in main chapters. Other useful features of the book include an elaborate chapter-by-chapter list of symbols, worked examples, exercises and quiz questions at the end of each chapter, and extensive authors' and subject index. This book will be of interest to all students taking courses in electrical measurements as a part of a B.Tech. in electrical engineering. Professionals in the field of electrical engineering will also find the book of use.


Proceedings of the RILEM International Symposium on Bituminous Materials

Proceedings of the RILEM International Symposium on Bituminous Materials

Author: Hervé Di Benedetto

Publisher: Springer Nature

Published: 2021-09-25

Total Pages: 1806

ISBN-13: 3030464555

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This volume highlights the latest advances, innovations, and applications in bituminous materials and structures and asphalt pavement technology, as presented by leading international researchers and engineers at the RILEM International Symposium on Bituminous Materials (ISBM), held in Lyon, France on December 14-16, 2020. The symposium represents a joint effort of three RILEM Technical Committees from Cluster F: 264-RAP “Asphalt Pavement Recycling”, 272-PIM “Phase and Interphase Behaviour of Bituminous Materials”, and 278-CHA “Crack-Healing of Asphalt Pavement Materials”. It covers a diverse range of topics concerning bituminous materials (bitumen, mastics, mixtures) and road, railway and airport pavement structures, including: recycling, phase and interphase behaviour, cracking and healing, modification and innovative materials, durability and environmental aspects, testing and modelling, multi-scale properties, surface characteristics, structure performance, modelling and design, non-destructive testing, back-analysis, and Life Cycle Assessment. The contributions, which were selected by means of a rigorous international peer-review process, present a wealth of exciting ideas that will open novel research directions and foster new multidisciplinary collaborations.


Advances in Asphalt Materials

Advances in Asphalt Materials

Author: Shin-Che Huang

Publisher: Woodhead Publishing

Published: 2015-04-08

Total Pages: 493

ISBN-13: 0081002718

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The urgent need for infrastructure rehabilitation and maintenance has led to a rise in the levels of research into bituminous materials. Breakthroughs in sustainable and environmentally friendly bituminous materials are certain to have a significant impact on national economies and energy sustainability. This book will provide a comprehensive review on recent advances in research and technological developments in bituminous materials. Opening with an introductory chapter on asphalt materials and a section on the perspective of bituminous binder specifications, Part One covers the physiochemical characterisation and analysis of asphalt materials. Part Two reviews the range of distress (damage) mechanisms in asphalt materials, with chapters covering cracking, deformation, fatigue cracking and healing of asphalt mixtures, as well as moisture damage and the multiscale oxidative aging modelling approach for asphalt concrete. The final section of this book investigates alternative asphalt materials. Chapters within this section review such aspects as alternative binders for asphalt pavements such as bio binders and RAP, paving with asphalt emulsions and aggregate grading optimization. Provides an insight into advances and techniques for bituminous materials Comprehensively reviews the physicochemical characteristics of bituminous materials Investigate asphalt materials on the nano-scale, including how RAP/RAS materials can be recycled and how asphalt materials can self-heal and rejuvenator selection


Analytical Methods in Petroleum Upstream Applications

Analytical Methods in Petroleum Upstream Applications

Author: Cesar Ovalles

Publisher: CRC Press

Published: 2015-04-02

Total Pages: 2054

ISBN-13: 1138001481

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Effective measurement of the composition and properties of petroleum is essential for its exploration, production, and refining; however, new technologies and methodologies are not adequately documented in much of the current literature. Analytical Methods in Petroleum Upstream Applications explores advances in the analytical methods and instrumentation that allow more accurate determination of the components, classes of compounds, properties, and features of petroleum and its fractions. Recognized experts explore a host of topics, including: A petroleum molecular composition continuity model as a context for other analytical measurements A modern modular sampling system for use in the lab or the process area to collect and control samples for subsequent analysis The importance of oil-in-water measurements and monitoring The chemical and physical properties of heavy oils, their fractions, and products from their upgrading Analytical measurements using gas chromatography and nuclear magnetic resonance (NMR) applications Asphaltene and heavy ends analysis Chemometrics and modeling approaches for understanding petroleum composition and properties to improve upstream, midstream, and downstream operations Due to the renaissance of gas and oil production in North America, interest has grown in analytical methods for a wide range of applications. The understanding provided in this text is designed to help chemists, geologists, and chemical and petroleum engineers make more accurate estimates of the crude value to specific refinery configurations, providing insight into optimum development and extraction schemes.