Application of Sessile Drop Method to Determine Surface Free Energy of Asphalt and Aggregate
Application of Sessile Drop Method to Determine Surface Free Energy of Asphalt and Aggregate

Author: Jianming Wei

Publisher:

Published: 2012

Total Pages: 7

ISBN-13:

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Surface free energy is an important parameter to determine the work of adhesion between the asphalt binder and the aggregate, which is related to the moisture damage of asphalt mixture. In this study, the sessile drop technique was performed to obtain the contact angle between asphalt/aggregate and different probe liquids. The surface free energies of asphalt and aggregate were characterized on the basis of the Owens-Wendt's theory. It was found that the sessile drop technique is a convenient way to determine the static contact angle. A test procedure was developed to offer a clear method to prepare the sample and measure the contact angle. The surface free energy of aggregate determined in this study was found to be smaller than that measured in other techniques because of equilibrium spreading pressure. The work of adhesion calculated from surface free energy can be utilized to choose the best combination of asphalt and aggregate, which can work as a reference in the selection of materials. Meanwhile, it was found that for the same aggregate, the pull-off strength and the work of adhesion of each asphalt-aggregate have the same trend of ranking.

Bituminous Mixtures and Pavements VIII
Bituminous Mixtures and Pavements VIII

Author: A.F. Nikolaides

Publisher: CRC Press

Published: 2024-06-21

Total Pages: 999

ISBN-13: 1040147089

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Bituminous Mixtures and Pavements VIII contains 114 papers as presented at the 8th International Conference ‘Bituminous Mixtures and Pavements’ (8th ICONFBMP, 12-14 June 2024, Thessaloniki, Greece). The contributions reflect the research and practical experience of academics and practicing engineers from thirty-four (34) different countries, and cover a wide range of topics: Session I: Bitumen, Modified binders, Aggregates, and Subgrade Session II: Bituminous mixtures (Design, Construction, Testing, Performance) Session III: Pavements (Design, Construction, Maintenance, Sustainability, Energy and Environmental consideration) Session IV: Pavement management and Geosynthetics Session V: Pavement recycling Session VI: Pavement surface characteristics, Pavement performance monitoring, Safety Session VII: Biomaterials in pavement engineering Session VIII: Prediction models of pavement performance Bituminous Mixtures and Pavements VIII covers recent advances in highway materials technology and pavement engineering, and will be of interest to scientists and professionals involved or interested in these areas. The ICONFBMP-conferences have been organized every four years since 1992. This 8th conference was jointly organized by: Laboratory of Highway Engineering, Aristotle University of Thessaloniki, Greece; Built Environment Research Institute (BERI), University of Ulster, UK; University of Texas San Antonio (UTSA), USA; Laboratory for Advanced Construction Technology (LACT), Technological Institute of Iowa, USA; Technological University of Delft (TUDelft), The Netherlands, and University of Antwerp, (UA), Belgium.

Ground Improvement Techniques
Ground Improvement Techniques

Author: T. G. Sitharam

Publisher: Springer Nature

Published: 2021-03-24

Total Pages: 396

ISBN-13: 9811599882

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This volume presents select papers presented at the 7th International Conference on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics. The papers discuss advances in the fields of soil dynamics and geotechnical earthquake engineering. Some of the themes include slope stability, shallow and deep foundations, geosynthetics, ground improvement techniques, etc. A strong emphasis is placed on connecting academic research and field practice, with many examples, case studies, best practices, and discussions on performance based design. This volume will be of interest to researchers and practicing engineers alike.

Issues in Teaching and Education Policy, Research, and Special Topics: 2013 Edition
Issues in Teaching and Education Policy, Research, and Special Topics: 2013 Edition

Author:

Publisher: ScholarlyEditions

Published: 2013-05-01

Total Pages: 858

ISBN-13: 1490110879

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Issues in Teaching and Education Policy, Research, and Special Topics: 2013 Edition is a ScholarlyEditions™ book that delivers timely, authoritative, and comprehensive information about Education Testing and Evaluation. The editors have built Issues in Teaching and Education Policy, Research, and Special Topics: 2013 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Education Testing and Evaluation in this book to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Teaching and Education Policy, Research, and Special Topics: 2013 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Introduction to Unmanned Aircraft Systems, Second Edition
Introduction to Unmanned Aircraft Systems, Second Edition

Author: Douglas M. Marshall

Publisher: CRC Press

Published: 2015-10-26

Total Pages: 1944

ISBN-13: 113802693X

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The proliferation of technological capability, miniaturization, and demand for aerial intelligence is pushing unmanned aerial systems (UAS) into the realm of a multi-billion dollar industry. This book surveys the UAS landscape from history to future applications. It discusses commercial applications, integration into the national airspace system (NAS), System function, operational procedures, safety concerns, and a host of other relevant topics. The book is dynamic and well-illustrated with separate sections for terminology and web- based resources for further information.

Evaluation of Compatibility Between Asphalt Binders and Mineral Aggregates
Evaluation of Compatibility Between Asphalt Binders and Mineral Aggregates

Author: Tandra Bagchi

Publisher:

Published: 2020

Total Pages: 87

ISBN-13:

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One of the major problems of asphalt concrete pavements faced by most state Departments of Transportations (DOTs) and other highway agencies is moisture damage. Poor compatibility between asphalt binders and aggregates is the main reason behind such kind of distresses. This study aims to conduct compatibility analyses of selected asphalt binders and aggregates used in Arkansas. Asphalt binders used in this study include two Performace Grade (PG) binders (PG 64-22) from two different sources along with their modified counterparts. Additionally, four different types of aggregates are being evaluated in the laboratory. The Sessile Drop method has been followed to determine surface free energy (SFE) of the selected binder-aggregate systems. The SFE data are then used to determine the compatibility between the asphalt binders and the aggregates. The findings of this study are expected to help pavement researchers and highway professionals to find suitable asphalt binder-aggregate combinations in constructing durable pavements.

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.

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.

Long and Deep Tunnels
Long and Deep Tunnels

Author: Vittorio Guglielmetti

Publisher: CRC Press

Published: 2016-04-15

Total Pages: 1336

ISBN-13: 0415558549

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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.