Download or read book Influence of Moisture on Bond Strength of Asphalt aggregate Systems written by Audrey R. Copeland and published by . This book was released on 2007 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characteristics of Asphalt Binders written by and published by . This book was released on 1996 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Coupled Micromechanical Model of Moisture induced Damage in Asphalt Mixtures written by Silvia Caro Spinel and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The deleterious effect of moisture on the structural integrity of asphalt mixtures has been recognized as one of the main causes of early deterioration of asphalt pavements. This phenomenon, usually referred to as moisture damage, is defined as the progressive loss of structural integrity of the mixture that is primarily caused by the presence of moisture in liquid or vapor state. Moisture damage is associated with the development of different physical, mechanical, and chemical processes occurring within the microstructure of the mixture at different intensities and rates. Although there have been important advancements in identifying and characterizing this phenomenon, there is still a lack of understanding of the damage mechanisms occurring at the microscopic level. This situation has motivated the research work reported in this dissertation. The main objective of this dissertation is to formulate and apply a numerical micromechanical model of moisture-induced damage in asphalt mixtures. The model focuses on coupling the effects of moisture diffusion-one of the three main modes of moisture transport within asphalt mixtures-with the mechanical performance of the microstructure. Specifically, the model aims to account for the effect of moisture diffusion on the degradation of the viscoelastic bulk matrix of the mixture (i.e., cohesive degradation) and on the gradual deterioration of the adhesive bonds between the aggregates and the asphalt matrix (i.e., adhesive degradation). The micromechanical model was applied to study the role of some physical and mechanical properties of the constitutive phases of the mixtures on the susceptibility of the mixture to moisture damage. The results from this analysis suggest that the diffusion coefficients of the asphalt matrix and aggregates, as well as the bond strength of the aggregate-matrix interface, have the most influence on the moisture susceptibility of the mixtures. The micromechanical model was further used to investigate the influence of the void phase of asphalt mixtures on the generation of moisture-related deterioration processes. Two different probabilistic-based approaches were used to accomplish this objective. In the first approach, a volumetric distribution of air void sizes measured using X-Ray Computed Tomography in a dense-graded asphalt mixture was used to generate probable void structures in a microstructure of an asphalt mixture. In the second approach, a stochastic modeling technique based on random field theory was used to generate probable air void distributions of the mixture. In this second approach, the influence of the air void was accounted for by taking the physical and mechanical properties of the asphalt matrix dependent on probable void distributions. Although both approaches take into consideration the characteristics of the air void phase on the mechanical response of the mixtures subjected to moist environments, the former explicitly introduces the air phase within the microstructure while the latter indirectly includes its effects by modifying the material properties of the bulk matrix. The results from these simulations demonstrated that the amount, variability and location of air voids are decisive in determining the moisture-dependent performance of asphalt mixtures. The results from this dissertation provide new information on the kinetics of moisture damage mechanisms in asphalt mixtures. In particular, the results obtained from applying the micromechanical model permitted identification of the relative influence of the characteristics of the constitutive phases of a mixture on its moisture-related mechanical performance. This information can be used as part of design methodologies of asphalt mixtures, and/or as an input in life-cycle analysis models and maintenance programs of road infrastructure.
Download or read book The Effect of the Physical and Chemical Characteristics of the Aggregate on Bonding written by A. R. Tarrer and published by . This book was released on 1991 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Moisture Damage in Asphalt Concrete written by Russell G. Hicks and published by Transportation Research Board. This book was released on 1991 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: This synthesis will be of interest to pavement designers, construction engineers, maintenance engineers, and others interested in avoiding or limiting moisture damage in asphalt concrete. Information is provided on physical and chemical explanations for moisture damage in asphalt concrete, along with a discussion of current practices and test methods for determining or reducing the susceptibility of various asphalt concrete components and mixtures to such damage. Moisture damage in asphalt concrete is a nationwide problem which often necessitates premature replacement of highway pavement surfaces. This report of the Transportation Research Board describes the underlying physical and chemical phenomena responsible for such damage. Current test methods used to determine the susceptibility of asphalt concretes, or their constituents, to moisture damage are described and evaluated. Additionally, current practices for minimizing the potential for moisture damage are examined.
Download or read book Proceedings of the 7th International Conference on Materials Engineering and Nanotechnology 2023 ICMEN 2023 04 05 Nov Kuala Lumpur Malaysia written by Ching Yern Chee and published by Springer Nature. This book was released on 2024 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zusammenfassung: This book includes selected peer reviewed articles presented at the 7th International Conference on Materials Engineering and Nanotechnology 2023 (ICMEN 2023) held on 04-05Nov at Kuala Lumpur in Malaysia. It highlights recent innovative approach and developments in materials engineering and nanotechnology fields. A broad range of topics and issues in modern materials science and nanotechnology are discussed, including advanced materials synthesis and characterization, nanoscale science and engineering, functional composite and nanomaterials, sustainable materials and green technologies. The importance and relevance of these proceedings lie in their contribution to the scientific community's collective knowledge and understanding of materials science/engineering and nanotechnology. By disseminating cutting-edge research findings and innovations, these proceedings foster collaboration, inspire new ideas, and push the boundaries of scientific discovery. Given its scope, this book will be of interest to a wide readership, including materials and nanotechnology engineers, scholars and researchers in science, technology and engineering disciplines
Download or read book Effect of Prolonged Heating on the Asphalt aggregate Bond Strength of HMA Containing Liquid Anti strip Additives written by Akhtarhusein Asgarali Tayebali and published by . This book was released on 2008 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book System for the Evaluation of Moisture Damage Using Fundamental Material Properties written by and published by . This book was released on 2007 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Test Method to Determine Aggregate asphalt Adhesion Properties and Potential Moisture Damage written by Andrew Hanz and published by . This book was released on 2007 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hot mix Asphalt Mixtures written by and published by . This book was released on 1999 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of Critical Factors Determining the Accuracy of Binder Bond Strength Test to Evaluate Adhesion Properties of Asphalt Binders written by W. Huang and published by . This book was released on 2016 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The bond strength between asphalt and aggregates is a crucial parameter in evaluating the ability of asphalt mixture resistance to moisture-induced damage. Factors affecting the bond strength were investigated based on the binder bond strength (BBS) test. The effects of asphalt film thickness and loading rate on the results of the BBS test and the relationship between these two factors were further studied. Then, specimens were subjected to four moisture conditions to study the impact of water on the bond strength. Furthermore, the impact of the complex modulus on the bond strength was studied using the dynamic shear rheometer (DSR) test. Finally, the pull-off test results were compared with the findings obtained from the Hamburg wheel-tracking device (HWTD) test regarding the moisture sensitivity of mixtures under dry and wet conditions. Results indicate that the pull-off tensile strength (POTS) increased with an increase of the loading rate, whereas POTS decreased with the increase of the film thickness. It was proved that an equivalent relationship between these two factors existed in the BBS test. It is interesting that the measured POTS values were basically equal when the loading curves of the same asphalt overlap under different combinations of film thickness and loading rate. Water had a significant impact on the bond strength, and the moisture condition in the early state was important in determining the moisture sensitivity of the mixtures. Furthermore, POTS increased with the complex modulus of asphalt binder, whereas the phase angle of asphalt determined the extent to which the film thickness will affect the BBS test results. The comparison of the BBS and HWTD tests confirmed that the BBS test could address the mixture resistance to water damage.
Download or read book Influence of Aggregate Binder Adhesion on Fatigue Life of Asphalt Mixtures written by Jorge Luiz Oliveira Lucas Júnior and published by . This book was released on 2020 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The adhesiveness between aggregate and asphalt binder is believed to affect the life cycle of asphalt pavements, mainly in the presence of water. One of the most common asphalt pavement distresses is fatigue cracking. The objective of this article is to investigate the relationship between adhesion properties and fatigue life of asphalt mixtures. The asphalt bond strength test was used to measure adhesion (pull-off tensile strength) at two different moisture conditioning states: unconditioned (or dry) and conditioned in distilled water for 24 h at 40°C. The test consists of measuring the pull-off pressure required to break an aggregate-binder interface, called the pull-off tensile strength. For the fatigue damage characterization of the mixtures, controlled crosshead sinusoidal tension-compression tests were used, associated with the Simplified Viscoelastic Continuum Damage modeling protocol. Four asphalt mixtures were investigated. They share the same aggregate gradation but differ in aggregate source (two different sources) and the presence or absence of an anti-stripping agent. The mixture with pure asphalt binder showed higher values of pull-off tensile strength than mixtures with asphalt binder doped by an anti-stripping agent. However, the analysis of the pull-off tensile strength ratio (comparison between unconditioned and moisture-conditioned specimens) showed that the addition of anti-stripping agent provided significant moisture damage resistance in the aggregate-binder interface. Results also show that mixtures with asphalt binder modified by anti-stripping agent had higher simulated fatigue life than mixtures with pure asphalt binder. Excellent correlations were obtained between the strain amplitude required to obtain a given @ Nf (strain amplitude @ Nf ) with pull-off tensile strength, which confirms that the fatigue life of asphalt mixtures is related to the adhesion between aggregate and asphalt binder.
Download or read book Effect of Prolonged Heating on the Asphalt Aggregate Bond Strength of HMA Containing Liquid Anti strip Additives written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT Venkata Lakshman Mandapaka. Effect of prolonged heating on the Asphalt-Aggregate Bond Strength of HMA containing Liquid Anti-strip Additives (Under the direction of Dr. A.A. Tayebali and Dr. Detlef Knappe) In this study, an attempt was made to determine the effect of prolonged heating on the bond strength between aggregate and asphalt that contained anti-strip additive (LOF 6500 of various percentages). A series of tests, namely Tensile Strength Ratio test (TSR), Contact Angle test, Pneumatic Adhesion test and Atomic Force Microscopy (AFM) test were performed, and the results obtained from each of these tests were compared to come to a reliable conclusion regarding effectiveness of the various tests for assessing the effect of prolonged heating on the adhesive bond strength. Results obtained from the Tensile Strength Ratio test showed that, as the prolonged heating duration increased the adhesive strength between the asphalt and aggregate was reduced. These results suggest that the non-volatilized portion of the anti-strip additive that remained in the asphalt after prolonged heating increased the moisture sensitivity of the asphalt-aggregate mixture, increased to the point where the mixtures failed the limiting TSR value of 85% as followed by NCDOT specification. Following the Tensile Strength Ratio test, Contact Angle test and Pull-Off test were performed in anticipation of expecting similar results that were obtained for the Tensile Strength Ratio test. However, due to complex interactions of such parameters as mixing of the anti-strip additive in asphalt cement, cleaning up of the glass/quartz slides, various temperature conditions, etc., the results obtained were inconclusive. Atomic Force Microscopy test was also not observed to be a good test for determination of the adhesive strength between the asphalt-aggregate. Hence, based on the results obtained we recommend that the Contact Angle test, Pull-Off test and Atomic Force Microscopy test are not eff.
Download or read book Influence of the Chemical Composition of Aggregates in the Adhesion Quality and Durability of Asphalt aggregate Systems written by Andrés Felipe Cala Pérez and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Rock mineralogy is critical in determining the adhesion quality and moisture susceptibility of asphalt-aggregate systems in asphalt mixtures. This work aims at identifying the chemical properties of aggregates that influence the quality and durability of these systems. To accomplish this goal, three lithologies with an ample mineralogical and chemical spectrum (i.e. quartzite, granodiorite and serpentinite) were selected. Asphalt-aggregate specimens fabricated with these lithologies were tested using a new pull-off experiment in dry condition, and after 1, 3 and 7 days of being submerged in water. The results show that rocks of mafic composition (e.g. serpentinite) have better resistance to moisture damage than felsic rocks (e.g. quartzite and granodiorite), and that certain specific aggregate oxides promote or prevent moisture degradation in these systems.
Download or read book Eleventh International Conference on the Bearing Capacity of Roads Railways and Airfields written by Inge Hoff and published by CRC Press. This book was released on 2022-07-07 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt: Innovations in Road, Railway and Airfield Bearing Capacity – Volume 2 comprises the second part of contributions to the 11th International Conference on Bearing Capacity of Roads, Railways and Airfields (2022). In anticipation of the event, it unveils state-of-the-art information and research on the latest policies, traffic loading measurements, in-situ measurements and condition surveys, functional testing, deflection measurement evaluation, structural performance prediction for pavements and tracks, new construction and rehabilitation design systems, frost affected areas, drainage and environmental effects, reinforcement, traditional and recycled materials, full scale testing and on case histories of road, railways and airfields. This edited work is intended for a global audience of road, railway and airfield engineers, researchers and consultants, as well as building and maintenance companies looking to further upgrade their practices in the field.
Download or read book Measurements of Surface Energy and Its Relationship to Moisture Damage written by and published by . This book was released on 2005 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Issues in Land and Water Engineering 2011 Edition written by and published by ScholarlyEditions. This book was released on 2012-01-09 with total page 884 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Land and Water Engineering / 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Land and Water Engineering. The editors have built Issues in Land and Water Engineering: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Land and Water Engineering in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Land and Water Engineering: 2011 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/.
