Laboratory Evaluation of the Impact of Additives on Asphalt Binders Usded in Cold Regions PDF Download

Author: Neirouz Bouhrira
Publisher:
ISBN:
Category : Asphalt
Languages : en
Pages : 137

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Author: Wade A. Lein
Publisher:
ISBN:
Category : Arctic regions
Languages : en
Pages :

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Low-temperature cracking is the main distress in asphalt pavement in cold regions (such as the arctic and subarctic regions) as the climate in these areas is severe in winter. While soft asphalt binders (such as PG 52-34 and PG 52-28) are used in the cold regions, asphalt pavements can still exhibit premature cracking failures. One of the approaches to solve this issue is to modify binders using additives. However, it is not clear which additives can significantly improve the thermal cracking resistance of binders. Therefore, there is a need to find potential additives resulting in improved resistance to thermal cracking because of extreme low temperatures experienced in cold regions. In this study, five additives [nano TiO2, nano SiO2, styrene-butadiene-styrene (SBS), ground tire rubber (GTR), and corn oil-based softening agent (SA)] were applied at various dosages with two soft base binders (PG 52-28 and PG 64E-40). Performance properties of modified binders were evaluated using the dynamic shear rheometer (DSR), standard bending beam rheometer (BBR), and modified BBR. The testing results indicated that the combination of a 7% softening agent and 7.5% SBS exhibited the highest improvement in the resistance to thermal cracking. Meanwhile, this combination also resulted in two performance grade bumps at high temperatures. Based on the laboratory testing results, the combination of a softening agent and high SBS could be potential additives to create high-performance binders for cold regions.

Author: Bradley J. Putnam
Publisher:
ISBN:
Category : Asphalt
Languages : en
Pages : 178

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The use of hydrated lime or other liquid anti stripping agents (ASA) is the most common method to improve the moisture susceptibility of asphalt mixes. However, most laboratory test conditions used to evaluate the moisture susceptibility of the mixes are only for a short duration of time. This might not be a good representation of the field conditions (i.e., several months or years of service). Thus, a study to evaluate the effects of conditioning the mixes for longer durations was initiated. Also, another problem with the use of the liquid anti stripping agents is their heat storage stability. This report addresses these two issues, by preparing and testing mixtures made with fresh binder for indirect tensile strength after conditioning the samples for 1, 7, 28, 90 and 180 days, and samples prepared from binder stored for three days at 160° C after conditioning them for 1, 28 and 90 days. The results of this study indicated that hydrated lime and the liquid anti stripping agents were equally effective for the mixes used in this research when conditioned beyond one day. In the case of samples prepared from stored binder, there was no significant difference in the effectiveness of hydrated lime and the liquid anti stripping agents even after conditioning for one day. Though it was observed that none of the ASA treatments performed better than others in the case of samples prepared with stored binder, it was also observed that almost all mixes gave significantly similar wet ITS and TSR values as samples prepared from fresh binder.

Author: Shivani Rani
Publisher:
ISBN:
Category : Asphalt
Languages : en
Pages : 16

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Different technologies, namely foamed asphalt, synthetic waxes, zeolites, and chemical additives, are used to produce warm mix asphalt (WMA). This study was undertaken to evaluate the effect of using different amounts of an amine-based chemical WMA additive on the rheology, performance grade (PG), and moisture-induced damage potential of an asphalt binder (PG 58-28). Superpave specifications were used to evaluate the rheological properties and PG of the asphalt binder. Also, a mechanistic approach-based on the surface free energy (SFE) method was used to evaluate the moisture-induced damage potential of the asphalt binder combined with commonly used aggregates in an asphalt mix. It was found that the dynamic viscosity of the asphalt binder was not significantly affected after blending it with the WMA additive. It was also observed that the Superpave high-temperature PG and the rutting factor did not reduce by an increase in the WMA additive content. However, the continuous low-temperature PG of the asphalt binder decreased with an increase in the amount of WMA additive. Furthermore, it was found that the fatigue resistance increased after blending the binder with the WMA additive. The SFE results of the asphalt binder revealed that the WMA additive used in this study reduced the moisture-induced damage potential of the asphalt mixes. However, the extent of this improvement was found to largely depend on the aggregate type. The outcomes of this study are expected to help better understand the influence of amine-based chemical WMA additives on rheological and long-term performance of asphalt mix.

Author: Joe W. Button
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 107

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The overall objective of this study was to evaluate a variety of asphalt additives in the laboratory and in the field to determine their merit in reducing cracking and rutting. In the late 1980s, test pavements were constructed in Texarkana, Sherman, San Benito, and Ft. Worth, Texas. In 1995, cores were obtained from Texarkana and Sherman and evaluated in the laboratory. Asphalt binders, retained during construction and sealed in cans, were tested using the Superpave binder tests and certain chemical tests. Retained binders and aggregates were combined in accordance with the original mixture designs, compacted in the laboratory, and tested using the NCHRP asphalt aggregate mixture analysis system (AAMAS) test protocols to assess relative resistance to fatigue cracking. The specific objective of the work reported herein was to test the binders and mixtures to determine what properties correlate with the field cracking. A secondary objective was to evaluate the ability of the laboratory tests to identify binders and mixtures susceptible to cracking.

Author:
Publisher:
ISBN:
Category : Asphalt
Languages : en
Pages : 144

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Author: Corina Borroel Wong
Publisher:
ISBN:
Category : Thesis
Languages : en
Pages : 264

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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.

Author: NM. Wasiuddin
Publisher:
ISBN:
Category : Acids
Languages : en
Pages : 9

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In this study, the effect of antistrip additives on asphalt binders was evaluated by both laboratory tests and a proposed chemical model of asphalt binder based on the surface free energy characteristics.Two performance graded asphalt binders, namely, PG 64-22 and PG 70-28 and two amine-based liquid antistrip additives, namely, AD-Here HP Plus and Redicote E-6 were evaluated at different percentages (0.25 %, 0.75 %, and 1.5 %) It was found that 1.5 %AD-Here HP Plus and 1.5 % Redicote E-6 increased the total SFE of PG 64-22 by 67 % and 208 %, respectively.Also, the acid components of PG 64-22 and PG 70-28 are 2.9 dyne/cm and 2.5 dyne/cm, respectively, whereas, the corresponding base components are 0.4 dyne/cm for both.With the addition of 1.5 %.Redicote E-6 in PG 64-22, the acid component of the binder reduced by 92 % and the base component of the binder increased by 1141 %.

Author: David G. Tunnicliff
Publisher: Transportation Research Board
ISBN: 9780309053747
Category : Technology & Engineering
Languages : en
Pages : 68

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Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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