Evaluation of Epoxy Asphalt Concrete Damping Parameters Using Impact Resonance Test

Evaluation of Epoxy Asphalt Concrete Damping Parameters Using Impact Resonance Test PDF Author: Leilei Chen
Publisher:
ISBN:
Category : Concrete
Languages : en
Pages : 7

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Book Description
An evaluation of epoxy asphalt concrete (EAC) damping parameters based on the impact resonance test (IRT) is presented. The EAC beam specimens for the IRT were designed and tested under different temperatures. The damping parameters of EAC were then calculated via the logarithmic decrement method. The theoretical natural frequencies of the EAC beams were calculated and compared with the test results as a verification of the IRT, and the comparison results indicate that the IRT is an effective method for determining the damping parameters of EAC. Sensitivity analyses were conducted in order to evaluate the effect of load modes, structure types, and temperatures by means of IRT with different impulsive load modes under different temperatures for EAC beams with different support types. The results show that the damping parameters are not affected by the load modes and are affected little by the structural modes. However, they decrease significantly with increasing test temperature. The tested damping parameters can provide parameters for the accurate dynamic analysis of the EAC wearing course on bridge decks.

Evaluation of Epoxy Asphalt Concrete Damping Parameters Using Impact Resonance Test

Evaluation of Epoxy Asphalt Concrete Damping Parameters Using Impact Resonance Test PDF Author: Leilei Chen
Publisher:
ISBN:
Category : Concrete
Languages : en
Pages : 7

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Book Description
An evaluation of epoxy asphalt concrete (EAC) damping parameters based on the impact resonance test (IRT) is presented. The EAC beam specimens for the IRT were designed and tested under different temperatures. The damping parameters of EAC were then calculated via the logarithmic decrement method. The theoretical natural frequencies of the EAC beams were calculated and compared with the test results as a verification of the IRT, and the comparison results indicate that the IRT is an effective method for determining the damping parameters of EAC. Sensitivity analyses were conducted in order to evaluate the effect of load modes, structure types, and temperatures by means of IRT with different impulsive load modes under different temperatures for EAC beams with different support types. The results show that the damping parameters are not affected by the load modes and are affected little by the structural modes. However, they decrease significantly with increasing test temperature. The tested damping parameters can provide parameters for the accurate dynamic analysis of the EAC wearing course on bridge decks.

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

Issues in Teaching and Education Policy, Research, and Special Topics: 2013 Edition PDF Author:
Publisher: ScholarlyEditions
ISBN: 1490108254
Category : Education
Languages : en
Pages : 888

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Book Description
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/.

Characterization of Asphalt Mixtures and Rap Binder Properties Through Impact Resonance Test

Characterization of Asphalt Mixtures and Rap Binder Properties Through Impact Resonance Test PDF Author: Ilker Boz
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Characterization of asphalt concrete is of paramount importance for the sound structural design and analysis of flexible pavements. Of equal importance is the availability of test methods that can provide an accurate and reliable measure of the required engineering properties of the material. For routine applications in material characterization, selected test methods should be reliable, simple, quick, repeatable, and cost eective. The use of nondestructive test (NDT) methods has proven to provide such characterization capabilities. Among those methods, the impact resonance (IR) test is a vibration based NDT method, and has been increasingly used for asphalt concrete evaluation and characterization in the past two decades. The majority of studies regarding the IR test in asphalt concrete applications have been focused on comparison of the IR test moduli with the moduli obtained from conventional asphalt concrete dynamic modulus tests and the predictive equations. In this dissertation, the IR test was utilized to characterize the properties of asphalt concrete mixtures and recycled asphalt pavement (RAP) binder through mixture testing at a range of temperatures. To this eect, several independent studies were conducted.The second order equation of motion assumption in rheological modeling of the IR test response was evaluated for asphalt concrete testing. A set of asphalt concrete specimens was tested with the IR test, and the obtained signals at a range of temperatures were evaluated by means of the Hankel matrix method. The results showed that the assumption is violated for asphalt concrete testing, especially at high temperatures, mainly due to the presence of noise in the obtained response. However, the Hankel method was employed to filter out the noise. It was seen that the assumption could be employed for asphalt concrete at a range of temperatures including high temperatures, provided that the filtering is performed on the obtained signal. The results also showed that the employed filtering procedure produced improvements for the IR test material dependent responses, resonant frequency and especially damping ratio calculations.The IR test results are influenced by specimen size and testing configurations. A study was conducted to investigate the influence of aspect ratio (length/diameter) of laboratory specimens on the frequency response of asphalt concrete when tested with the IR. The IR test, performed in a longitudinal mode, demonstrated that the test is repeatable and reproducible. The test results indicated that the frequency response increased as the aspect ratio increased approximately up to 0.7, and then it decreased with a nonlinear trend as the aspect ratio increased beyond 0.7, indicating that the tendency of the frequency response reached a plateau as the aspect ratio increased. It was inferred from the test results that there was a threshold aspect ratio at which the fundamental longitudinal frequency mode was not the dominant frequency mode. Velocity calculations from measured resonant frequencies indicated that the true material properties for the longitudinal mode could be attained at an aspect ratio of as low as 1.In another study, the sensitivity of the resonant frequency response of the IR testing of asphalt concrete to asphalt concrete mixture parameters was investigated. The IR tests were performed on disk-shaped asphalt concrete specimens at the transverse (flexural) mode of vibration at a temperature range of approximately -10 to 50oC. Test results revealed that the relationship between the resonant frequency and temperature was described by a polynomial fit, and it was shown through statistical analysis that the slopes of the fit were significantly aected by mixture parameters such as air void content and binder content. Also, the statistical formulation (predictive model) between the resonant frequency and the asphalt concrete mixture parameters were established for a given aggregate gradation of nominal maximum size and an aggregate specific gravity. The prediction accuracy of the model was evaluated by independent data sets, and the test results indicated that the maximum error between the measured and predicted resonant frequencies was not more than 9 percent.In an eort to characterize the properties of recycled asphalt pavement (RAP) binder with the IR test through asphalt concrete mixture testing, two approaches were utilized. An approach is proposed for determination of binder properties through the IR testing of mixtures with RAP and binders with known engineering properties. The IR tests were performed in the longitudinal mode at a range of temperatures between 3 and 35oC. Also, RAP binder and virgin binders were tested using dynamic shear rheometer (DSR) at the same temperature range as the IR testing. It was seen that the IR test ranked the expected trend of binder stiness with respect to the resonant frequency of mixtures. The results indicate the potential of the proposed concept and feasibility of the approach in determining binder properties, including properties of the RAP binder. A practical method is proposed for determination of binder properties based on mixture testing.In the second approach, the IR test potential to characterize the low-temperature properties of an RAP binder that incorporated a rejuvenating agent was investigated. This approach included testing of mixes with virgin binders and pure RAP mixes treated with a rejuvenating agent at dierent levels using the IR, as well as testing of blends of recovered RAP binder, rejuvenator, and virgin binder using bending beam rheometer (BBR). The results showed that the IR test can properly rank the expected stiness of binders through mixture testing. The results also indicated high linear correlations between mixture properties obtained from the IR test (modulus and phase angle) and binder properties obtained from the BBR test (stiness and m-value, a relaxation index). The results clearly demonstrate the potential of IR to be used for grading and optimization for the asphalt binder of RAP and rejuvenator content in lieu of the binder recovery method.

Determination of Dynamic Modulus Values of Asphalt Mixtures Using Impact Resonance Testing of Thin Disk Specimens

Determination of Dynamic Modulus Values of Asphalt Mixtures Using Impact Resonance Testing of Thin Disk Specimens PDF Author: D. Kim
Publisher:
ISBN:
Category : Dynamic modulus (|E*|)
Languages : en
Pages : 12

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Book Description
The impact resonance (IR) test is a nondestructive test method that is used to characterize the linear viscoelastic behavior of asphalt concrete. This method is preferred over other methods because the setup of the IR test is simpler, more efficient, and less expensive than standard axial compression dynamic modulus (|E*|) tests. Researchers originally developed the IR test method for cylindrical specimens of asphalt mixtures and concluded that this method can serve as an alternative to |E*| tests. However, the geometry (100 mm in diameter by 150 mm in height) of the cylindrical specimens used in these tests prohibits the use of IR tests for field cores. Therefore, researchers began to consider thin disk-shaped specimens for IR testing because thinner geometry of such specimens better represents slices of field cores. In this study, a test procedure was developed to evaluate the use of thin disk-shaped specimens for IR tests in order to determine the |E*| values of asphalt mixtures. The IR test protocol was optimized using 2 IR test methods (referred to as Case 1 and Case 2 in this work) under various test conditions to ensure the highest possible quality of the data. Optimal test methods were proposed based on the repeatability and variability of the resonant frequency and phase angle data and the ability of the different test conditions to provide data that best match the |E*| values obtained from standard axial compression |E*| tests. The results demonstrate that the |E*| values of thin disk-shaped specimens determined from the optimized IR tests are similar to the |E*| values of long cylindrical specimens determined from conventional |E*| AASHTO T 342-11 tests and IR tests.

Resistance of Concrete to Freezing and Thawing

Resistance of Concrete to Freezing and Thawing PDF Author: Donald J. Janssen
Publisher: Strategic Highway Research Program (Shrp)
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 228

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Book Description
This study, aimed at improving the freeze-thaw resistance of concrete, consists of three parts. Part I evaluates parameters affecting the freeze-thaw durability of concrete. A modification of the existing standard of method for determining the durability factor of concrete specimens is proposed, and a new procedure for fundamental transverse frequency (used in durability factor calculations) has been developed. Part II focuses on developing better methods for identifying nondurable aggregates, and has resulted in a rapid new test based on the hydraulic fracture of aggregates. Part III describes field experiments to evaluate the freeze-thaw resistance of a number of specified concrete mixes and the use of sealants to mitigate D-cracking. Preliminary field performance results are presented.

Micro and Nanostructured Epoxy / Rubber Blends

Micro and Nanostructured Epoxy / Rubber Blends PDF Author: Sabu Thomas
Publisher: John Wiley & Sons
ISBN: 3527333347
Category : Technology & Engineering
Languages : en
Pages : 462

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Book Description
Epoxy resins are polymers which are extensively used as coating materials due to their outstanding mechanical properties and good handling characteristics. A disadvantage results from their high cross-link density: they are brittle and have very low resistance to crack growth and propagation. This necessitates the toughening of the epoxy matrix without impairing its good thermomechanical properties. The final properties of the polymer depend on their structure. The book focuses on the microstructural aspects in the modification of epoxy resins with low molecular weight liquid rubbers, one of the prime toughening agents commonly employed. The book follows thoroughly the reactions of elastomer-modified epoxy resins from their liquid stage to the network formation. It gives an in-depth view into the cure reaction, phase separation and the simultaneous development of the morphology. Chapters on ageing, failure analysis and life cycle analysis round out the book.

Structural Vibration

Structural Vibration PDF Author: C. Beards
Publisher: Elsevier
ISBN: 0080518052
Category : Technology & Engineering
Languages : en
Pages : 289

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Book Description
Many structures suffer from unwanted vibrations and, although careful analysis at the design stage can minimise these, the vibration levels of many structures are excessive. In this book the entire range of methods of control, both by damping and by excitation, is described in a single volume.Clear and concise descriptions are given of the techniques for mathematically modelling real structures so that the equations which describe the motion of such structures can be derived. This approach leads to a comprehensive discussion of the analysis of typical models of vibrating structures excited by a range of periodic and random inputs. Careful consideration is also given to the sources of excitation, both internal and external, and the effects of isolation and transmissability. A major part of the book is devoted to damping of structures and many sources of damping are considered, as are the ways of changing damping using both active and passive methods. The numerous worked examples liberally distributed throughout the text, amplify and clarify the theoretical analysis presented. Particular attention is paid to the meaning and interpretation of results, further enhancing the scope and applications of analysis. Over 80 problems are included with answers and worked solutions to most. This book provides engineering students, designers and professional engineers with a detailed insight into the principles involved in the analysis and damping of structural vibration while presenting a sound theoretical basis for further study.Suitable for students of engineering to first degree level and for designers and practising engineersNumerous worked examplesClear and easy to follow

Chemistry and Technology of Thermosetting Polymers in Construction Applications

Chemistry and Technology of Thermosetting Polymers in Construction Applications PDF Author: M.H. Irfan
Publisher: Springer Science & Business Media
ISBN: 9401149542
Category : Technology & Engineering
Languages : en
Pages : 297

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Book Description
Polymeric products are used widely in the construction industry, because they offer a range of desirable performance properties not available from traditional materials. Development of these products continues in a number of major research and development programmes within the construction materials sector, aimed at improving the performance, durability and applicational properties of these materials. It seems certain that their use will increase as their overall performance is developed and as the industry becomes more familiar with the techniques required to apply these materials and the benefits they offer. The purpose of this book is to familiarise the reader with the range of thermosetting polymeric materials available for construction applications, and to provide sound information on the properties and applications of these important materials. Professional engineers involved in the specification, application and testing of these materials will find this book a compact, authoritative and comprehensive source of information on these materials. Chemists and technologists involved in developing new or improved formulations will find in this book much to inform their work, particularly in the important area of applicational properties.

Chemical Abstracts

Chemical Abstracts PDF Author:
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 2566

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Book Description


Internal Friction in Metallic Materials

Internal Friction in Metallic Materials PDF Author: Mikhail S. Blanter
Publisher: Springer Science & Business Media
ISBN: 3540687580
Category : Technology & Engineering
Languages : en
Pages : 553

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Book Description
This book is a unique collection of experimental data in the field of internal friction, anelastic relaxation, and damping properties of metallic materials. It reviews virtually all anelastic relaxation phenomena ever published. The reader is also supplied with explanations of the basic physical mechanisms of internal friction, a summary of typical effects for different groups of metals, and more than 2000 references to original papers.