Effects of Moist Aggregates on the Performance of Warm Mix Asphalt Mixtures Containing Non-Foaming Additives

Effects of Moist Aggregates on the Performance of Warm Mix Asphalt Mixtures Containing Non-Foaming Additives
Author: V. S. Punith
Publisher:
Total Pages: 11
Release: 2011
Genre: Environment friendly asphalt mixture
ISBN:

The objective was to conduct a laboratory investigation of moisture susceptibility and rutting resistance of non-foaming warm mix asphalt (WMA) mixtures containing moist aggregates. Gyration number and weight loss of various samples, indirect tensile strength (ITS), tensile strength ratio (TSR), rut depths of dry and moisture conditioned specimens, as well as failed temperatures and rutting factors of recovered binders were measured for all mixtures. The experimental design included two aggregate moisture contents (0 and ~0.5 % by weight of the dry mass of the aggregate), two lime contents (1 and 2 % lime by weight of dry aggregate) and one liquid anti-stripping agent (ASA), three non-foaming WMA additives (Cecabase®, Evotherm®, and Rediset®) with control, and two aggregate sources. A total of 34 mixtures were designed and a total of 340 specimens were tested in this study. The test results indicated that the aggregate source significantly affects the ITS and rutting resistance regardless of the WMA additive, ASA, and moisture content. In addition, the ITS and rut depth of the non-foaming WMA mixtures containing moist aggregates generally satisfied the demand of pavement without additional treatment. The mixtures with three WMA additives exhibited similar rutting resistance under dry and wet conditions. The liquid ASA, used in this study, for moisture resistance is not recommended to use in WMA mixtures containing moist aggregates as the aggregate is sensitive to moisture.

Evaluation of Warm Mix Additives for Use in Modified Asphalt Mixtures

Evaluation of Warm Mix Additives for Use in Modified Asphalt Mixtures
Author: Corina Borroel Wong
Publisher:
Total Pages: 264
Release: 2011
Genre: Thesis
ISBN:

The intention of this research effort is to evaluate the use of warm mix additives with typical polymer-modified and terminal blend tire rubber asphalt mixtures from Nevada and California. The research effort is broken into three phases that are intended to evaluate the impacts of warm mix additives with typical polymer-modified and terminal blend tire rubber asphalt mixtures from Nevada and California: moisture damage, performance characteristics, and mechanistic analysis. In Phase I of this research effort, mixture resistance to moisture damage was evaluated using the indirect tensile test and the dynamic modulus at multiple freeze-thaw cycles. Laboratory testing was conducted to address the following: (1) the impact of warm mix additive and reduced production temperatures on the moisture damage resistance of asphalt mixtures, (2) the impact of residual aggregate moisture on the moisture damage resistance of WMA mixtures, (3) the impact of warm mix additives on the moisture damage resistance of anti-strip treated WMA mixtures, and (3) the impact of long-term aging on strength gain and the moisture damage resistance of WMA mixtures. A total of one aggregate source, four warm mix asphalt technologies (Advera, Sasobit, Revix and Foaming) and three asphalt binder types (neat, polymer-modified and terminal blend tire rubber modified asphalt binders) typically used in both Nevada and California are being evaluated in this study. This thesis will only summarize the test results and findings of the Phase I of the study for two warm-mix additives: Advera and Sasobit. The evaluation of the other two technologies (i.e. Revix and Foaming) as well as the Phase II testing are still in progress and have not been completed.

8th RILEM International Symposium on Testing and Characterization of Sustainable and Innovative Bituminous Materials

8th RILEM International Symposium on Testing and Characterization of Sustainable and Innovative Bituminous Materials
Author: Francesco Canestrari
Publisher: Springer
Total Pages: 1024
Release: 2015-09-24
Genre: Technology & Engineering
ISBN: 9401773424

This work presents the results of RILEM TC 237-SIB (Testing and characterization of sustainable innovative bituminous materials and systems). The papers have been selected for publication after a rigorous peer review process and will be an invaluable source to outline and clarify the main directions of present and future research and standardization for bituminous materials and pavements. The following topics are covered: - Characterization of binder-aggregate interaction - Innovative testing of bituminous binders, additives and modifiers - Durability and aging of asphalt pavements - Mixture design and compaction analysis - Environmentally sustainable materials and technologies - Advances in laboratory characterization of bituminous materials - Modeling of road materials and pavement performance prediction - Field measurement and in-situ characterization - Innovative materials for reinforcement and interlayer systems - Cracking and damage characterization of asphalt pavements - Recycling and re-use in road pavements This is the proceedings of the RILEM SIB2015 Symposium (Ancona, Italy, October 7-9, 2015).

Proceedings of the 9th International Conference on Maintenance and Rehabilitation of Pavements—Mairepav9

Proceedings of the 9th International Conference on Maintenance and Rehabilitation of Pavements—Mairepav9
Author: Christiane Raab
Publisher: Springer Nature
Total Pages: 955
Release: 2020-06-19
Genre: Technology & Engineering
ISBN: 3030486796

This book gathers the proceedings of an international conference held at Empa (Swiss Federal Laboratories for materials Science and Technology) in Dübendorf, Switzerland, in July 2020. The conference series was established by the International Society of Maintenance and Rehabilitation of Transport Infrastructure (iSMARTi) for promoting and discussing state-of-the-art design, maintenance, rehabilitation and management of pavements. The inaugural conference was held at Mackenzie Presbyterian University in Sao Paulo, Brazil, in 2000. The series has steadily grown over the past 20 years, with installments hosted in various countries all over the world. The respective contributions share the latest insights from research and practice in the maintenance and rehabilitation of pavements, and discuss advanced materials, technologies and solutions for achieving an even more sustainable and environmentally friendly infrastructure.

Sustainable Construction Materials

Sustainable Construction Materials
Author: Ravindra K. Dhir
Publisher: Woodhead Publishing
Total Pages: 0
Release: 2017-10-18
Genre: Technology & Engineering
ISBN: 9780081009970

Sustainable Construction Materials: Municipal Incinerated Bottom Ash discusses the global use of virgin aggregates and CO2 polluter Portland cement. Given the global sustainability agenda, much of the demand for these two sets of materials can be substantially reduced through the appropriate use of waste materials, thereby conserving natural resources, energy and CO2 emissions. Realistically, this change can only be realized and sustained through engineering ingenuity and new concepts in design. Although a great deal of research has been published over the last 50 years, it remains fragmented and ineffective. This book develops a single global knowledge-base, encouraging greater use of selected waste streams. The focus of massive systematic reviews is to encourage the uptake of recycled secondary materials (RSM) by the construction industry and guide researchers to recognize what is already known regarding waste.

Determining the Limitations of Warm Mix Asphalt by Water Injection in Mix Design, Quality Control and Placement

Determining the Limitations of Warm Mix Asphalt by Water Injection in Mix Design, Quality Control and Placement
Author: Ala R. Abbas
Publisher:
Total Pages: 125
Release: 2013
Genre: Asphalt
ISBN:

In this project, a comprehensive study was conducted to evaluate the laboratory performance of foamed WMA mixtures with regard to permanent deformation, moisture-induced damage, fatigue cracking, and low-temperature (thermal) cracking; and compare it to traditional HMA. In addition, the workability of foamed WMA and HMA mixtures was evaluated using a new device that was designed and fabricated at the University of Akron, and the compactability of both mixtures was examined by analyzing compaction data collected using the Superpave gyratory compactor. The effect of the temperature reduction, foaming water content, and aggregate moisture content on the performance of foamed WMA was also investigated. Furthermore, the rutting performance of plant-produced foamed WMA and HMA mixtures was evaluated in the Ohio University (OU) Accelerated Pavement Load Facility (APLF), and the long-term performance of pavement structures constructed using foamed WMA and HMA surface and intermediate courses was analyzed using the Mechanistic-Empirical Pavement Design Guide (MEPDG). The laboratory test results revealed comparable resistance to permanent deformation, moisture-induced damage, and fatigue cracking for foamed WMA and HMA mixtures. However, the HMA mixtures had significantly higher ITS values at 14°F (-10°C) and comparable failure strains to the foamed WMA mixtures, which indicates that the traditional HMA mixtures have better resistance to low-temperature (thermal) cracking. The laboratory tests conducted to evaluate the effect of the temperature reduction, foaming water content, and aggregate moisture content revealed that the performance of foamed WMA mixtures prepared using 30°F (16.7°C) temperature reduction, 1.8% foaming water content, and fully dried aggregates was comparable to that of the HMA mixtures. However, reducing the production temperature of foamed WMA resulted in increased susceptibility to permanent deformation and moisture-induced damage. In addition, producing foamed WMA using moist aggregates resulted in inadequate aggregate coating leading to concerns with regard to long-term durability. Increasing the foaming water content (up to 2.6% of the weight of the asphalt binder) did not seem to have a negative effect on the rutting performance or moisture sensitivity of the foamed WMA. The rut depth measurements obtained at the OU APLF confirmed the laboratory APA test results. It was found through these tests that the foamed WMA mixtures have comparable rutting resistance to the HMA mixtures. Finally, the long-term pavement performance predictions obtained using the MEPDG showed comparable service lives for pavement structures constructed using foamed WMA and HMA surface and intermediate mixtures.

Evaluation of the Moisture Susceptibility of WMA Technologies

Evaluation of the Moisture Susceptibility of WMA Technologies
Author: Amy Epps Martin
Publisher: Transportation Research Board
Total Pages: 109
Release: 2014
Genre: Technology & Engineering
ISBN: 030928368X

"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

Performance Evaluation of Foamed Warm Mix Asphalt Produced by Water Injection

Performance Evaluation of Foamed Warm Mix Asphalt Produced by Water Injection
Author: Ayman Ali
Publisher:
Total Pages: 201
Release: 2013
Genre: Asphalt
ISBN:

In recent years, a new group of technologies has been introduced in the United States that allow producing asphalt mixtures at temperatures 30 to 100oF lower than what is used in traditional hot mix asphalt (HMA). These technologies are commonly referred to as Warm Mix Asphalt (WMA). From among these technologies, foamed WMA produced by water injection has gained increased attention from the asphalt paving industry in Ohio since it does not require the use of costly additives. This type of asphalt mixtures is advertised as an environmentally friendly alternative to traditional HMA and promoted to have better workability and compactability. In spite of these advantages, several concerns have been raised regarding the performance of foamed WMA because of the reduced production temperature and its impact on aggregate drying and asphalt binder aging. Main concerns include increased propensity for moisture-induced damage (durability) and increased susceptibility to permanent deformation (rutting). Other concerns include insufficient coating of coarse aggregates, and applicability of HMA mix design procedures to foamed WMA mixtures. This dissertation presents the results of a comprehensive study conducted to evaluate the laboratory performance of foamed WMA mixtures with regard to permanent deformation, moisture-induced damage, fatigue cracking, and low-temperature (thermal) cracking; and compare it to traditional HMA. In addition, the workability of foamed WMA and HMA mixtures was evaluated using a new device that was designed and fabricated at the University of Akron, and the compactability of both mixtures was examined by analyzing compaction data collected using the Superpave gyratory compactor. The effect of the temperature reduction, foaming water content, and aggregate moisture content on the performance of foamed WMA was also investigated. Furthermore, the rutting performance of plant-produced foamed WMA and HMA mixtures was evaluated in the Accelerated Pavement Load Facility (APLF) at Ohio University, and the long-term performance of pavement structures constructed using foamed WMA and HMA surface and intermediate courses was analyzed using the Mechanistic-Empirical Pavement Design Guide (MEPDG). Based on the experimental test results and the subsequent analyses findings, the following are the main conclusions made: In general, comparable laboratory test results were obtained for foamed WMA and HMA mixtures prepared using 30°F (16.7°C) temperature reduction, 1.8% foaming water content, and fully dried aggregates. Therefore, the performance of the resulting foamed WMA is expected to be similar to that of the HMA. Surface foamed WMA mixtures had comparable rutting performance in the APLF to that of the HMA mixtures. This was also the case for intermediate foamed WMA and HMA mixtures. These results indicate the field performance of the foamed WMA mixtures is similar to that of the HMA mixtures.

Isolated Or Coupled Oxidative, Moisture, and Freeze-thaw Effects on Warm Mix Asphalt

Isolated Or Coupled Oxidative, Moisture, and Freeze-thaw Effects on Warm Mix Asphalt
Author: Carl Pittman
Publisher:
Total Pages: 70
Release: 2018
Genre:
ISBN:

This thesis aims to contribute to the growing body of warm mix asphalt (WMA) research by evaluating the differences in behavioral properties of three WMA mixtures, representing the three warm mix technology (WMT) categories (foaming, chemical additives, and organic waxes), relative to a control hot mix asphalt (HMA) in a specific set of conditions which is not well documented in literature. These conditions are: plant produced mixtures with all virgin aggregates and binder (i.e. no recycled materials) and no additives other than the warm mix technology. These mixtures were evaluated at low, intermediate, and high testing temperatures before and after a set of conditioning protocols (CPs), which utilized varying levels of isolated and combined oxidative, moisture, and freeze-thaw damage. A key feature of this thesis is that damage induced by these CPs has been benchmarked relative to measured field aging effects through studies which evaluated the three WMA mixtures and one HMA mixture used to obtain the results presented here, along with additional mixtures not considered in this thesis.