Download or read book Characterization of Thermal Degradation of Liquid Amine Anti Strip Additives in Asphalt Binders Due to RTFO and PAV Aging written by Nazimuddin M. Wasiuddin and published by . This book was released on 2007 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Effect of Antistrip Additives on Surface Free Energy Characteristics of Asphalt Binders for Moisture Induced Damage Potential written by NM. Wasiuddin and published by . This book was released on 2007 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 %.
Download or read book Quantify Antitrip Additives in Asphalt Binders and Mixes written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Quantitative Analysis of Amine based Liquid Antistrip Additives in Asphalt written by Richard Ulrich and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantitative Analysis of Amine Based Liquid Antistrip Additive in Asphalt written by Robert Scott Cantrell and published by . This book was released on 1997 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Examination of Significant Binder Aging Due to the Use of Different Anti Stripping Additives in Polymer and CRM Asphalt Mixtures Using GPC written by Sungun Kim and published by . This book was released on 2020 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Aging Characterization of Foamed Warm Mix Asphalt written by Mir Shahnewaz Arefin and published by . This book was released on 2015 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Quantitative analysis of amine based liquid antistrip additives in asphalt written by and published by . This book was released on 1997 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laboratory Evaluation of Anti strip Additives in Hot Mix Asphalt written by Bradley J. Putnam and published by . This book was released on 2006 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
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 Rheological Chemical and Microstructural Characterization of Asphalt Binders Aged at Different Conditions and Evaluation of the Use of Antioxidants and Copolymers to Retard Aging written by Mohammad Solaiman Khan and published by . This book was released on 2017 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rheological, chemical and microstructural properties of asphalt binders change with oxidative aging which is accelerated at elevated temperatures. Aging stiffens asphalt binders and increases the embrittlement of asphalt mixtures which would lead to fatigue cracking and eventually pavement failure under repetitive traffic loading. This study explored the feasibility of using antioxidant additives and copolymers with antioxidant agents to retard oxidative aging of asphalt binders. The performance of the additives was evaluated at the binder and mastic levels. The laboratory experiments included two unmodified binders, various antioxidant additives and copolymers, and three aggregate types. The fatigue characteristics of asphalt binders and mastic were determined before and after aging and an aging index was defined to evaluate the effect of the additives on aging. The results demonstrated that certain antioxidants and copolymers such as Redicote AP, Solprene, and Calprene may retard the aging and improve the rheological properties of the asphalt binders. In addition, the results of mastic testing confirmed the favorable effect of certain antioxidants on improving the resistance to fatigue cracking. Furthermore, the type of aggregate was found to influence the rate of aging of asphalt mixtures. Based on the rheological and fracture test results on asphalt binders and mastic, the effect of antioxidants was further investigated and validated at spectroscopic, chemical and microstructural level using Fourier-transform infrared spectroscopy (FTIR), Gel-permeation chromatography (GPC) and Atomic Force Microscopy (AFM), respectively. The spectroscopic analysis with FTIR supported the efficacy of the additives in retarding aging by reducing the carbonyl growth in aged binders. The chemical analysis with GPC confirmed that both Redicote and Solprene were capable of reducing the large molecular size fraction in binders subjected to long-term aging. The image analysis with AFM provided insight on the spatial distribution, surface roughness parameters and micromechanical properties (i.e., adhesion, stiffness) of various phases and the effect of aging on the micro-rheology of antioxidant-modified binders. The last part of this study examined the effect of aging on the viscoelastic response of asphalt mixture using the Prony series representation and a newly developed parameter called aging state variable 'A'. The dynamic modulus test data was used for the analysis. The aging state variable 'A' was found to capture the effect of aging temperature and duration of aging on the viscoelastic properties of asphalt mixtures.
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 The Use of DMA to Characterize the Aging of Asphalt Binders written by Ioan I. Negulescu and published by . This book was released on 2010 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents issues associated with long-term aging of polymer modified asphalt cements (PMACs) as reflected by dynamic mechanical analysis (DMA) data. In this study a standard SBS (styrene-butadiene-styrene block copolymer) polymer modified asphalt cement containing 3% copolymer (PMAC) meeting LADOTD specifications for PAC-40HG and PG 76-22M was selected and subjected to accelerated laboratory aging. Procedures were developed for simulation of long term aging of asphalt binders using multiple pressure aging vessel (PAV) operations in the absence and in the presence of water. Three, five and seven year old field aged asphalt samples originally of similar PMAC composition as that of PG 76-22 listed above were recovered from a wearing course mixture located on interstate I-55 near Granada, MS. All binders were characterized with respect to their composition and rheological properties.
Download or read book Rapport over de economische toestand van Engeland sedert het loslaten van de gouden standaard written by and published by . This book was released on 1935* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Liquid Anti stripping Additives on the Performance of Asphalt Binder in Hot Mix Asphalt written by Kathryn Page Copeland and published by . This book was released on 2005 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Use of Phosphoric Acid to Stiffen Hot Mix Asphalt Binders written by Terry Arnold and published by . This book was released on 2014 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document offers guidelines for the use of phosphoric acid to stiffen asphalt binders for hot mix paving applications. Data are presented on the likely effect on pavement life, moisture resistance, and use with limestone aggregates and liquid amine antistrip additives. Analytical methods for the detection of phosphoric acid in asphalt binders are also presented. Asphalt producers, hot-mix paving contractors, and State departments of transportation are the main audiences.
Download or read book A Comparison of Warm Asphalt Binder Aging with Laboratory Aging Procedures written by Tejash Gandhi and published by . This book was released on 2010 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Warm asphalt has been gaining increasing popularity in recent years; however there are several characteristics about warm asphalt that are still unknown. While several studies have been conducted to study the performance of warm asphalt mixtures, aging characteristics of warm mix asphalt (WMA) binders are not known in great detail. This paper presents the results of a limited study to evaluate the aging characteristics of two WMA binders artificially aged in the rolling thin film oven (RTFO) and the pressure aging vessel and comparing them with binder extracted from freshly prepared and artificially aged warm asphalt mixtures. RTFO aging was performed at 163°C and a lower temperature to simulate warm asphalt aging. Tests on binders aged in the laboratory and binders extracted from freshly mixed and aged mixtures indicated that the WMA binders extracted from WMA mixtures had significantly lower viscosities and G*/sin ? compared to binders extracted from hot mix asphalt (HMA) and binders aged in the RTFO at 163°C (325°F). This indicates that the lower mixing and compaction temperatures reduce the aging of the warm asphalt binders. Also, binders extracted from WMA had significantly lower creep stiffness values and significantly higher m-values compared to warm asphalt binders aged in the RTFO at 163°C (325°F) and binders extracted from HMA. Binders containing WMA additives did not have higher G* sin ? values, indicating that the warm asphalt additives do not negatively affect the fatigue properties of the binders. Gel permeation chromatography analysis indicated that the addition of the warm asphalt additives did not have any significant effect on the %LMS of the binders used in this study.
