Author(s):
S. Hu, F. Zhou, T. Scullion
Publication Date
October 2014
Abstract
Recent studies show some mixes with softer binders used outside of Texas (e.g., Minnesota's Cold Weather Road Research Facility mixes) have both good rutting and cracking performance. However, the current binder performance grading (PG) system fails to justify/identify this phenomenon, particularly as it applies to softer but highly modified binders. Therefore, it is necessary to improve the current asphalt grading system and recommend associated specification limits, especially for modified binders. The major objectives of this research project were to (a) identify/develop simple lab evaluation methods to characterize binder properties, (b) recommend potential binder specification changes, (c) track the field performance of pavements using different binders including softer but highly modified binders, and (e) develop a statewide catalogue of binder recommendations for each district based on cracking performance simulation and life cycling analysis results. Since the binder lab evaluation methods and recommendations have been documented in Report 0-6647-1, this report mainly focuses on field test section performance predictions/simulations and the statewide catalogue of binder recommendations. Eleven test sections using different binder types and binder contents, with and without Reclaimed Asphalt Pavement (RAP) or Reclaimed Asphalt Shingles (RAS), were built and monitored during this project. This report documents the construction information, plant mix lab testing results, and performance survey/prediction results. Through validated performance prediction models, the researchers conducted 2700 cracking performance simulations to cover different asphalt mixtures, climate zones, overlay thicknesses, traffic levels, and existing pavement structures. the statewide catalogue of binder recommendations was developed based on the simulation results. The life cycling cost analysis was conducted in three typical climate-zone districts--Amarillo (cold), Austin (moderate), and Pharr (hot)--and further justified the potential use of softer but highly modified binders in Texas, especially in cold areas.
Report Number:
0-6674-2
Keywords:
Adhesion Test, asphalt binder, Fracture Test, Multiple Stress Creep Recovery Test
Link(s):
Document/Product
http://tti.tamu.edu/documents/0-6674-2.pdf
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