Characterization of Thermal Degradation of Liquid Amine Anti-Strip Additives in Asphalt Binders Due to RTFO and PAV-Aging

Characterization of Thermal Degradation of Liquid Amine Anti-Strip Additives in Asphalt Binders Due to RTFO and PAV-Aging PDF Author: Nazimuddin M. Wasiuddin
Publisher:
ISBN:
Category : Acids
Languages : en
Pages : 8

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Book Description
In this study, thermal degradation of amine-based liquid anti-strip additives was evaluated due to RTFO-aging and PAV-aging according to AASHTO T 240 and AASHTO R 28 test methods, respectively. The surface free energy (SFE) characteristics of asphalt binders before and after aging were used as a tool for this evaluation. Two asphalt binders, namely PG 64-22 and PG 70-28, and two anti-strip additives, namely AD-Here HP Plus and Redicote E-6, were evaluated. It was observed for 0.75 % AD-Here HP Plus in PG 64-22, mixing at 163°C is more effective than mixing at 145°C with respect to increase in SFE. Also, both RTFO and PAV-aging decrease the total SFE of asphalt binders; both the aging processes are more effective in PG 64-22. In addition, the beneficial effect of anti-strip additives in acid-base characteristics of asphalt binders is severely reduced by RTFO and PAV-aging. Finally, the chemical model of asphalt binder, proposed by Wasiuddin , was expanded to include the SFE characteristics of asphalt binders due to aging.

Characterization of Thermal Degradation of Liquid Amine Anti-Strip Additives in Asphalt Binders Due to RTFO and PAV-Aging

Characterization of Thermal Degradation of Liquid Amine Anti-Strip Additives in Asphalt Binders Due to RTFO and PAV-Aging PDF Author: Nazimuddin M. Wasiuddin
Publisher:
ISBN:
Category : Acids
Languages : en
Pages : 8

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Book Description
In this study, thermal degradation of amine-based liquid anti-strip additives was evaluated due to RTFO-aging and PAV-aging according to AASHTO T 240 and AASHTO R 28 test methods, respectively. The surface free energy (SFE) characteristics of asphalt binders before and after aging were used as a tool for this evaluation. Two asphalt binders, namely PG 64-22 and PG 70-28, and two anti-strip additives, namely AD-Here HP Plus and Redicote E-6, were evaluated. It was observed for 0.75 % AD-Here HP Plus in PG 64-22, mixing at 163°C is more effective than mixing at 145°C with respect to increase in SFE. Also, both RTFO and PAV-aging decrease the total SFE of asphalt binders; both the aging processes are more effective in PG 64-22. In addition, the beneficial effect of anti-strip additives in acid-base characteristics of asphalt binders is severely reduced by RTFO and PAV-aging. Finally, the chemical model of asphalt binder, proposed by Wasiuddin , was expanded to include the SFE characteristics of asphalt binders due to aging.

Effect of Antistrip Additives on Surface Free Energy Characteristics of Asphalt Binders for Moisture-Induced Damage Potential

Effect of Antistrip Additives on Surface Free Energy Characteristics of Asphalt Binders for Moisture-Induced Damage Potential PDF Author: NM. Wasiuddin
Publisher:
ISBN:
Category : Acids
Languages : en
Pages : 9

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Book Description
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 %.

Quantify Antitrip Additives in Asphalt Binders and Mixes

Quantify Antitrip Additives in Asphalt Binders and Mixes PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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In this study, litmus and colorimetric tests were developed to quantify the contents of amine-based antistrip additives in asphalt binders and mixes. In addition, the effect of prolonged heating on antistrip additive content was evaluated for both asphalt binders and mixes. Results of this study indicate that both litmus and colorimetric tests are capable of detecting and quantifying amine-based antistrip additives in asphalt binders and mixes. Also, both test methods were able to validate the antistrip additive contents in field samples with known additive contents. When subjected to prolonged heating periods, the antistrip additive content decreased substantially for both asphalt binders and mixes. For asphalt binders, no antistrip additive content was detectable after 24 to 48 hours of extended heating; for mixes, the measured antistrip additive content approached non-detectable level after 6 to 12 hours of extended heating. Tensile Strength Ratio test was conducted in this research to evaluate the effect of prolonged heating on the asphalt-aggregate bond strength of hot mix asphalt (HMA) containing liquid antistrip additives. Improvement of moisture sensitivity by use of amine-based antistrip additive was observed to be lost to a great extent after prolonged heating. It shows that the remaining part of antistrip additive after prolonged heating has reduced effect on adhesion between asphalt and aggregate. The volatilization and⁄or chemical change that occur during the heating process of amine-based antistrip additive affect the improvement of asphalt-aggregate adhesion and ultimately the moisture susceptibility of mixes.

Quantitative Analysis of Amine-based Liquid Antistrip Additives in Asphalt

Quantitative Analysis of Amine-based Liquid Antistrip Additives in Asphalt PDF Author: Richard Ulrich
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ISBN:
Category : Amine oxidase
Languages : en
Pages : 0

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Quantitative Analysis of Amine Based Liquid Antistrip Additive in Asphalt

Quantitative Analysis of Amine Based Liquid Antistrip Additive in Asphalt PDF Author: Robert Scott Cantrell
Publisher:
ISBN:
Category : Amines
Languages : en
Pages : 142

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Examination of Significant Binder Aging Due to the Use of Different Anti-Stripping Additives in Polymer and CRM Asphalt Mixtures Using GPC

Examination of Significant Binder Aging Due to the Use of Different Anti-Stripping Additives in Polymer and CRM Asphalt Mixtures Using GPC PDF Author: Sungun Kim
Publisher:
ISBN:
Category : Asphalt emulsion mixtures
Languages : en
Pages : 12

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Book Description
As an anti-stripping agent (ASA), hydrated lime (HL) has been widely used for many years in the world. Many brands of liquid-type ASA (LA), which properly provided the anti-stripping function, have been also developed and marketed. Because HL was found to provide anti-aging function of the binder in the mix, in addition to anti-stripping function, its use was known to have many advantages of other beneficial functions to the asphalt pavement. However, because the anti-aging function of LA is in question, it will be important to recognize if the anti-aging function is presented by the LAs too. Therefore, this study investigated the anti-aging effect of HL and three LAs in normal, crumb rubber-modified and polymer-modified asphalt mixes, in terms of absolute viscosity (AV) estimated from the large molecular size (LMS) measured by gel permeation chromatography (GPC), a scientific equipment. It was found that HL provided a significant retardation of age hardening, compared with the binder of the mix without any ASA. However, unlikely the anti-stripping function, most of the LAs did not show age retardation effect. The anti-aging function of liquid additives was not proved in this study, and therefore, the significant difference in binder aging was present due to the use of different ASA.

Aging Characterization of Foamed Warm Mix Asphalt

Aging Characterization of Foamed Warm Mix Asphalt PDF Author: Mir Shahnewaz Arefin
Publisher:
ISBN:
Category : Asphalt
Languages : en
Pages : 129

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Book Description
This study evaluated the aging characteristic of foamed warm mix asphalt (WMA) produced by water injection in comparison to traditional hot mix asphalt (HMA). Four types of asphalt binders (PG 64-22, PG 64-28, PG 70-22, PG 76-22) were used in the preparation of the foamed WMA and HMA mixtures. All mixtures were prepared using limestone aggregates with a nominal maximum aggregate size (NMAS) of 12.5 mm that met the Ohio Department of Transportation (ODOT) Construction and Material Specifications (C&MS) for Item 442 (Superpave Asphalt Concrete).The short-term and long-term aging of the asphalt binders were simulated using the rolling thin film oven (RTFO) and the pressure aging vessel (PAV), respectively, while the short-term and long-term aging of the laboratory-prepared asphalt mixtures were simulated according to AASHTO R 30 (Mixture Conditioning of Hot Mix Asphalt).The dynamic shear rheometer (DSR) was used to characterize the viscoelastic behavior of the unaged, RTFO-aged, and PAV-aged asphalt binders, while the dynamic modulus (lE*l) test was used to characterize the viscoelastic behavior of the short-term and long-term aged foamed WMA and HMA mixtures.In addition, the mechanistic-empirical pavement design guide (MEPDG) global aging model was used to predict the effect of aging on the dynamic modulus (lE*l) of foamed WMA and HMA mixtures, and the MEPDG global aging model predictions were compared to dynamic modulus (lE*l) test results obtained in the laboratory for both asphalt mixtures. By comparing the DSR test results following RTFO and PAV to those obtained for the unaged asphalt binders, it was observed that PG 64-22 was the least susceptible to aging followed by PG 70-22, PG 76-22, and PG 64-28. Similar trends were also observed from the dynamic modulus test, where little difference was noticed between the short-term and long-term aged specimens prepared using PG 64-22 for both foamed WMA and HMA mixtures.The dynamic modulus test results also revealed slightly lower lE*l values for foamed WMA mixtures in comparison to traditional HMA mixtures. This indicates that foamed WMA mixtures are slightly more susceptible to rutting than HMA mixtures. However, by comparing the dynamic modulus of the long-term aged specimens to the short-term aged specimens, it was observed that the increase in stiffness for the foamed WMA mixtures was less than that for the traditional HMA mixtures. This indicates that foamed WMA mixtures are less susceptible to aging and subsequently fatigue cracking than HMA mixtures.Finally, by the comparing the MEPDG global aging model predictions to the dynamic modulus test results for both foamed WMA and HMA mixtures, it was observed that the MEPDG global aging model provided more reasonable predictions, especially at higher frequencies, but overestimated or underestimated the dynamic modulus at lower frequencies. This was observed for both foamed WMA and HMA mixtures, which suggests that this model can be used for both types of mixtures.

Laboratory Evaluation of Anti-strip Additives in Hot Mix Asphalt

Laboratory Evaluation of Anti-strip Additives in Hot Mix Asphalt PDF Author: Bradley J. Putnam
Publisher:
ISBN:
Category : Asphalt
Languages : en
Pages : 178

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Book Description
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.

Quantitative analysis of amine-based liquid antistrip additives in asphalt

Quantitative analysis of amine-based liquid antistrip additives in asphalt PDF Author:
Publisher:
ISBN:
Category : Amine oxidase
Languages : en
Pages : 150

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Effect of Prolonged Heating on the Asphalt-aggregate Bond Strength of HMA Containing Liquid Anti-strip Additives

Effect of Prolonged Heating on the Asphalt-aggregate Bond Strength of HMA Containing Liquid Anti-strip Additives PDF Author: Akhtarhusein Asgarali Tayebali
Publisher:
ISBN:
Category : Asphalt concrete
Languages : en
Pages : 96

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