Evaluation of Anti-stripping Agents Using the Asphalt Pavement Analyzer
Evaluation of Anti-stripping Agents Using the Asphalt Pavement Analyzer

Author: Stephen A. Cross

Publisher:

Published: 2001

Total Pages: 120

ISBN-13:

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Moisture damage of asphalt mixes, better known as stripping, is a major distress affecting pavement performance. AASHTO T 283 (KT-56) has been used by many agencies over the past decade to detect moisture susceptible pavements through the determination of a tensile strength ratio (TSR). Results from AASHTO T 283 (KT-56) have been inconsistent. As a result, there has been increased interest in finding an alternative test method. Preliminary indications reveal that loaded wheel rut testers, such as the Asphalt Pavement Analyzer (APA), have the potential to detect moisture susceptible mixtures. To date no standard test methodology has been developed. The objective of this project was to evaluate the effects of sample preconditioning on APA rut depths and to further evaluate the APA's suitability for predicting moisture susceptible mixtures. Eight different mixes from seven project sites were evaluated with the APA. Samples were tested at 40 deg C using four different preconditioning procedures: dry, soaked, saturated, and saturated with a freeze cycle. The results were compared with TSR values, methylene blue values and sand equivalent. The APA was able to identify every mix with a failing TSR.

Evaluating Applications of Field Spectroscopy Devices to Fingerprint Commonly Used Construction Materials
Evaluating Applications of Field Spectroscopy Devices to Fingerprint Commonly Used Construction Materials

Author: Adam Zofka

Publisher: Transportation Research Board

Published: 2013

Total Pages: 263

ISBN-13: 0309129370

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"TRB's second Strategic Highway Research Program (SHRP 2) Report S2-R06B-RW-1: Evaluating Applications of Field Spectroscopy Devices to Fingerprint Commonly Used Construction Materials documents evaluation results of practical, portable spectroscopic equipment for in-situ analysis of a wide range of commonly used construction materials. The report also includes proposed American Association of State Highway and Transportation Officials (AASHTO) standards of practice for the analysis of titanium content in traffic paints by X-ray fluorescence and identification of chemical admixtures by attenuated total reflectance. The results of Renewal Project R06B, which produced SHRP 2 Report S2-R06B-RW-1, will be incorporated into an electronic repository for practitioners, known as the NDToolbox, which will provide information regarding recommended technologies for the detection of a particular deterioration. The NDToolbox is in the process of being created by SHRP 2 Renewal Project R06A, which has released SHRP 2 Report S2-R06A-RR-1: Nondestructive Testing to Identify Concrete Bridge Deck Deterioration that identifies nondestructive testing technologies for detecting and characterizing common forms of deterioration in concrete bridge decks. Renewal Project R06B is one of seven follow-on projects to SHRP Renewal Project R06 that produced SHRP 2 Report S2-R06-RW: A Plan for Developing High-Speed, Nondestructive Testing Procedures for Both Design Evaluation and Construction Inspection, which examines existing and emerging nondestructive evaluation (NDE) technologies and their current state of implementation to satisfy the NDE needs for highway renewal"--TRB Website.

Laboratory Evaluation of Anti-strip Additives in Hot Mix Asphalt
Laboratory Evaluation of Anti-strip Additives in Hot Mix Asphalt

Author: Bradley J. Putnam

Publisher:

Published: 2006

Total Pages: 178

ISBN-13:

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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.