Evaluation of Environmental Conditioning System for Predicting Moisture Susceptibility of Asphalt Concrete Mixtures PDF Download

Author: V. Tandon
Publisher:
ISBN:
Category :
Languages : en
Pages : 28

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Author: Nalini Vemuri
Publisher:
ISBN:
Category : Asphalt concrete
Languages : en
Pages : 284

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Author: Vivek Tandon
Publisher:
ISBN:
Category : Pavements, Asphalt concrete
Languages : en
Pages : 23

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Book Description
Many highway agencies face the problem of premature failure of asphalt concrete pavements due to moisture damage. Various laboratory tests have been used to predict the moisture susceptibility of asphalt concrete mixtures. Unfortunately, none of the available laboratory tests are able to accurately discriminate between well and poor performing mixes; that is, the laboratory test results do not necessarily correlate well with the field performance. Recent studies performed under the Strategic Highway Research Program (SHRP) indicate that the environmental conditioning system (ECS) is a device that better simulates the field conditions. Based on the initial studies, the ECS seemed to be able to distinguish moisture susceptible mixes. A study was undertaken at the University of Texas at El Paso (UTEP) to evaluate the ECS. Based on the results from this study, the ECS needs improvements both in terms of conditioning of asphalt concrete mixture, as well as, resilient modulus test setup.

Author: Mansour Solaimanian
Publisher: Transportation Research Board
ISBN: 0309099064
Category : Bituminous materials
Languages : en
Pages : 79

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Explores whether combining the environmental conditioning system with the simple performance test would provide a superior procedure for determining the moisture susceptibility of hot-mix asphalt (HMA).

Author: Vivek Tandon
Publisher:
ISBN:
Category : Pavements, Asphalt concrete
Languages : en
Pages : 4

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Author: Wendy L. Allen
Publisher:
ISBN:
Category : Asphalt concrete
Languages : en
Pages : 620

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The Environmental Conditioning System (ECS) was designed to evaluate the water sensitivity of asphalt concrete mixtures. The ECS subjects asphalt concrete specimens to a series of conditioning cycles including water flow, elevated and/or lowered temperature, and repeated axial loading. The purpose of this research was to: (1) evaluate the ECS test apparatus and procedure, and (2) determine whether the ECS can identify asphalt concrete mixtures that will perform well, or poorly, in the field with regard to water sensitivity. Twelve primary field test sections were identified. For each section, specimens were prepared in the laboratory using the original mix design (or the mix design identified by extraction), and the original aggregates, asphalts, and admixtures. Specimens were tested using two procedures: the ECS and the Oregon State University (OSU) wheel tracker. Field cores were used to evaluate in-situ mixture performance. Nine additional mixtures that have historically experienced water damage were tested in a limited secondary test program. Analyses were performed to determine the mixture properties that were significant in the prediction of mixture performance in the ECS. Mixture type was consistently the most significant predictor of ECS modulus ratio (change in mixture stiffness), degree of visual stripping, and binder migration, which were the performance indicators for water sensitivity evaluated in the ECS. Additional analysis indicated the existence of correlations among the ECS response variables. Significant correlations were found between the coefficient of water permeability and the degree of visual stripping; and between specimen deformation and the degree of visual stripping and binder migration. Mixture performance was compared between the ECS and the OSU wheel tracker and the field. Results indicate that the ECS test procedure can distinguish the relative performance of mixtures, with regard to water sensitivity, and mixture performance in the ECS correlates well with performance in the OSU wheel tracker. No correlation was found between mixture performance in the ECS and mixture performance in the field for the primary test sections. However, the primary field sections are relatively young, and water damage is expected to manifest itself in the future in those pavements identified as water sensitive by the ECS. The ECS predicted failure in the secondary mixtures which were identified as having had poor performance with regard to water sensitivity.

Author: Ronald L. Terrel
Publisher: National Research Council
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 204

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Book Description
The research presented in this report was conducted to identify the important factors influencing the water sensitivity of asphalt paving mixtures, and to develop a test method to evaluate water sensitivity of asphalt concrete mixtures for mix design. The test method was to be performance related. A review of current procedures revealed that no single method was suitable for evaluation and related to field performance. Based on a hypothesis that air voids in the mixture may be the major source and cause of water damage, a test system was developed to evaluate the major factors that influence water sensitivity. The Environmental Conditioning System (ECS) was used to develop a test procedure that includes specimen preparation; measurement of permeability using air, water, or both; vacuum wetting; cycling at various temperatures; and continuous repeated loading while monitoring resilient modulus after each conditioning cycle.

Author: A. Scarpas
Publisher: Springer Science & Business Media
ISBN: 9400745664
Category : Technology & Engineering
Languages : en
Pages : 1340

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Book Description
In the recent past, new materials, laboratory and in-situ testing methods and construction techniques have been introduced. In addition, modern computational techniques such as the finite element method enable the utilization of sophisticated constitutive models for realistic model-based predictions of the response of pavements. The 7th RILEM International Conference on Cracking of Pavements provided an international forum for the exchange of ideas, information and knowledge amongst experts involved in computational analysis, material production, experimental characterization, design and construction of pavements. All submitted contributions were subjected to an exhaustive refereed peer review procedure by the Scientific Committee, the Editors and a large group of international experts in the topic. On the basis of their recommendations, 129 contributions which best suited the goals and the objectives of the Conference were chosen for presentation and inclusion in the Proceedings. The strong message that emanates from the accepted contributions is that, by accounting for the idiosyncrasies of the response of pavement engineering materials, modern sophisticated constitutive models in combination with new experimental material characterization and construction techniques provide a powerful arsenal for understanding and designing against the mechanisms and the processes causing cracking and pavement response deterioration. As such they enable the adoption of truly "mechanistic" design methodologies. The papers represent the following topics: Laboratory evaluation of asphalt concrete cracking potential; Pavement cracking detection; Field investigation of pavement cracking; Pavement cracking modeling response, crack analysis and damage prediction; Performance of concrete pavements and white toppings; Fatigue cracking and damage characterization of asphalt concrete; Evaluation of the effectiveness of asphalt concrete modification; Crack growth parameters and mechanisms; Evaluation, quantification and modeling of asphalt healing properties; Reinforcement and interlayer systems for crack mitigation; Thermal and low temperature cracking of pavements; and Cracking propensity of WMA and recycled asphalts.

Author: Amy Epps Martin
Publisher: Transportation Research Board
ISBN: 030928368X
Category : Technology & Engineering
Languages : en
Pages : 109

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Book Description
"TRB's National Cooperative Highway Research Program (NCHRP) Report 763: Evaluation of the Moisture Susceptibility of WMA Technologies presents proposed guidelines for identifying potential moisture susceptibility in warm mix asphalt (WMA). The report also suggests potential revisions to the Appendix to AASHTO R 35, "Special Mixture Design Considerations and Methods for WMA" as a means to implement the guidelines."--publisher's description

Author: Bradley J. Bruce
Publisher:
ISBN:
Category : Pavements, Asphalt
Languages : en
Pages : 0

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Book Description
The actual moisture susceptibility of 10 bituminous mixtures placed in the field was compared to the moisture susceptibility that was predicted during the laboratory evaluation of the same mix design. Laboratory mixtures were evaluated using the modified Lottman procedure and the Root-Tunnicliff procedure, in addition to routine moisture susceptibility testing which includes immersion compression testing. After two years, cores were taken from the field projects. The condition of the cores and their present susceptibility to moisture damage were determined by performing modified Lottman and Root-Tunnicliff testing. A feature of the evaluation process was the use of the ACMODAS program to predict the remaining service life of the plant mix cores.