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 Effect of Prolonged Heating on the Asphalt Aggregate Bond Strength of HMA Containing Liquid Anti strip Additives written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT Venkata Lakshman Mandapaka. Effect of prolonged heating on the Asphalt-Aggregate Bond Strength of HMA containing Liquid Anti-strip Additives (Under the direction of Dr. A.A. Tayebali and Dr. Detlef Knappe) In this study, an attempt was made to determine the effect of prolonged heating on the bond strength between aggregate and asphalt that contained anti-strip additive (LOF 6500 of various percentages). A series of tests, namely Tensile Strength Ratio test (TSR), Contact Angle test, Pneumatic Adhesion test and Atomic Force Microscopy (AFM) test were performed, and the results obtained from each of these tests were compared to come to a reliable conclusion regarding effectiveness of the various tests for assessing the effect of prolonged heating on the adhesive bond strength. Results obtained from the Tensile Strength Ratio test showed that, as the prolonged heating duration increased the adhesive strength between the asphalt and aggregate was reduced. These results suggest that the non-volatilized portion of the anti-strip additive that remained in the asphalt after prolonged heating increased the moisture sensitivity of the asphalt-aggregate mixture, increased to the point where the mixtures failed the limiting TSR value of 85% as followed by NCDOT specification. Following the Tensile Strength Ratio test, Contact Angle test and Pull-Off test were performed in anticipation of expecting similar results that were obtained for the Tensile Strength Ratio test. However, due to complex interactions of such parameters as mixing of the anti-strip additive in asphalt cement, cleaning up of the glass/quartz slides, various temperature conditions, etc., the results obtained were inconclusive. Atomic Force Microscopy test was also not observed to be a good test for determination of the adhesive strength between the asphalt-aggregate. Hence, based on the results obtained we recommend that the Contact Angle test, Pull-Off test and Atomic Force Microscopy test are not eff.
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 Effect of Prolonged Heating on the Asphalt aggregate Bond Strength of HMA written by Venkata Lakshman Murthy Mandapaka and published by . This book was released on 2008 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: portable adhesion tester, Johnson-Kendell-Roberts, ductility, Tensile strength ratio, Wilhelmy Plate technique, de-ionized, anomalies.
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 Effects of Moist Aggregates on the Performance of Warm Mix Asphalt Mixtures Containing Non Foaming Additives written by V. S. Punith and published by . This book was released on 2011 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Special Mixture Design Considerations and Methods for Warm Mix Asphalt written by and published by Transportation Research Board. This book was released on 2012 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Report 714: Special Mixture Design Considerations and Methods for Warm-Mix Asphalt: A Supplement to NCHRP Report 673: A Manual for Design of Hot-Mix Asphalt with Commentary presents special mixture design considerations and methods used with warm-mix asphalt. NCHRP Report 714 is a supplement to NCHRP Report 673: A Manual for Design of Hot-Mix Asphalt. All references to chapters in NCHRP Report 714 refer to the corresponding chapters in NCHRP Report 673.
Download or read book A Manual for Design of Hot Mix Asphalt with Commentary written by and published by Transportation Research Board. This book was released on 2011 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of the Roles of Adhesion and Cohesion Properties of Asphalt Binders in Moisture Damage of HMA written by Kunnawee Kanitpong and published by . This book was released on 2005 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Evaluation of Warm Mix Additives for Use in Modified Asphalt Mixtures written by Corina Borroel Wong and published by . This book was released on 2011 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Effect of Anti Strip Agents on Temperature Susceptibility of Asphalt Cements written by Max I. Sheeler and published by . This book was released on 1987 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anti-strip agents can effect the temperature susceptibility of asphalt cement. This concern was expressed at the 33rd Annual Bituminous Conference in St. Paul, Minnesota by Mr. David Gendell, Director of Highway Operations. This study compares viscosity-temperature relationships of asphalt cement with and without anti-strip agent addition.
Download or read book Durability and Performance Characteristics of Hot Mix Asphalt Containing Polymer Additives written by Robert Y. Liang and published by . This book was released on 2001 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ohio Department of Transportation has adopted the hot mix asphalt concrete containing polymer modifiers for use in the interstate highway pavement. Among the various reasons cited for the adoption of polymer modifiers are the favorable field experiences by ODOT, extensive literatures reporting enhanced performance, such as rutting resistance, low temperature thermal cracking resistance, and possibly fatigue endurance. However, despite these favorable findings, there are still cases involving premature failure of hot mixtures containing polymer modifiers. Concerns regarding optimum polymer content, compatibility between polymer additives and asphalt cement, proper mixing and compaction procedure remain to be resolved. Furthermore, performance based specifications to ensure production of desirable final asphalt concrete product require additional development. Questions regarding the suitability of Superpave binder testing procedures for the polymer-modified binders need to be clarified.
Download or read book Effects of an Amine Anti Stripping Agent on Moisture Susceptibility of Sasobit and Aspha Min Mixes by Surface Free Energy Analysis written by Aravinda Buddhala and published by . This book was released on 2012 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Warm mix asphalt (WMA) is a fairly recent technology developed primarily to address issues such as high vapor emissions and high energy costs associated with the traditional hot mix asphalt (HMA) paving. Although the WMA is becoming a popular paving technology through field and laboratory evaluations, many researchers and transportation personnel are concerned about its moisture resistance. The present study analyzes the free energy of adhesion or wetting ability between eight different aggregates and an asphalt binder modified with varying dosages of two warm mix additives, namely Sasobit and Aspha-Min. Sasobit showed a maximum of 20.9 % and an average of 12.8 % increase in the free energy of adhesion in dry condition. The adhesion in the presence of moisture, referred to as free energy of reduction, was also evaluated to understand the moisture susceptibility of the WMA. The lower the free energy of reduction, the lower the asphalt binder's tendency to de-bond from aggregates in the presence of moisture. A maximum of 20.5 % and an average of 13.2 % decrease in the free energy of reduction were observed for asphalt binder with 3 % Sasobit. However, Aspha-Min did not exhibit any significant effect on any of the surface properties. One amine-based anti-stripping agent, AD-here HP Plus, is studied to evaluate its effect on adhesion and moisture susceptibility of the WMA. While its performance as an anti-stripping agent was good on the plain asphalt binder, AD-here HP Plus did not improve the adhesion of the selected binder modified with WMA additives either in dry or wet condition. The free energy of adhesion in wet and dry conditions showed either detrimental or no effect with selected aggregates, suggesting a negative or no influence of AD-here HP Plus on the WMA additive-modified 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 Effect of Aggregate Pretreatment with ASA on the Asphalt aggregate Bond written by Myung-Chan Jo and published by . This book was released on 1989 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
