Haul time effects on unmodified, foamed, and additive-modified binders used in hot-mix asphalt

IL Howard, GL Baumgardner… - Transportation …, 2013 - journals.sagepub.com
IL Howard, GL Baumgardner, WS Jordan III, AM Menapace, WS Mogawer…
Transportation research record, 2013journals.sagepub.com
In recent years, warm technologies have made enormous changes to the flexible pavement
industry in a variety of ways. Warm-mix asphalt is the most recognizable warm technology
product, although other advantages are associated with better compaction over a wide
range of temperatures and have made long-haul distances appealing for some applications.
This paper focuses on using warm-mix technology at traditional hot-mix production
temperatures for the purpose of facilitating long haul distances. The primary objective of this …
In recent years, warm technologies have made enormous changes to the flexible pavement industry in a variety of ways. Warm-mix asphalt is the most recognizable warm technology product, although other advantages are associated with better compaction over a wide range of temperatures and have made long-haul distances appealing for some applications. This paper focuses on using warm-mix technology at traditional hot-mix production temperatures for the purpose of facilitating long haul distances. The primary objective of this study was to investigate how binder-related properties change with haul time when material was mixed at hot-mix temperatures. A secondary objective was to determine if any behavioral differences were present between asphalt binders with no additive, foamed asphalt binders, and asphalt binders with a chemical additive. Plant-mixed asphalt was used for the investigation. The overall conclusion of the research was that haul times of 1 to 8 h produced no major differences in aging for a given binder type or between binder types. Subtle differences were observed between binder types in some instances (e.g., low-temperature properties were slightly better for mixes using warm-mix technologies).
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