TY - GEN
T1 - Binder oxidative aging in Texas pavements
T2 - Hardening rates, hardening susceptibilities, and impact of pavement depth
AU - Al-Azri, Nasser A.
AU - Jung, Sung Hoon
AU - Lunsford, Kevin M.
AU - Ferry, Ann
AU - Bullin, Jerry A.
AU - Davison, Richard R.
AU - Glover, Charles J.
PY - 2006
Y1 - 2006
N2 - Aging of binders in pavements is much less understood than laboratory aging of neat binders because of a number of complications. Complications include suitable extraction and recovery methods; uncontrolled variables and unknowns such as mixture characteristics (e.g., air voids), maintenance treatments, traffic, and climate; sustaining of a research effort to study a given pavement during an appropriate time frame (in excess of one decade); and cost. An ongoing research effort sponsored by the Texas Department of Transportation studied binder oxidative hardening at 15 pavements across Texas. Results indicate that typically unmodified binders in pavements oxidize and harden to a degree that exceeds generally accepted pavement aging assumptions. In addition, this hardening may extend much deeper into the pavement than has been previously assumed or documented. Data suggest that pavements can oxidize at surprisingly uniform rates with depth once early oxidation occurs and that these rates continue for an extended time. As a rough measure, 1 month environmental room aging of 1-mm neat binder films at 60°C was equivalent to about 15 months in Texas Highway 21 after the early higher hardening rate period.
AB - Aging of binders in pavements is much less understood than laboratory aging of neat binders because of a number of complications. Complications include suitable extraction and recovery methods; uncontrolled variables and unknowns such as mixture characteristics (e.g., air voids), maintenance treatments, traffic, and climate; sustaining of a research effort to study a given pavement during an appropriate time frame (in excess of one decade); and cost. An ongoing research effort sponsored by the Texas Department of Transportation studied binder oxidative hardening at 15 pavements across Texas. Results indicate that typically unmodified binders in pavements oxidize and harden to a degree that exceeds generally accepted pavement aging assumptions. In addition, this hardening may extend much deeper into the pavement than has been previously assumed or documented. Data suggest that pavements can oxidize at surprisingly uniform rates with depth once early oxidation occurs and that these rates continue for an extended time. As a rough measure, 1 month environmental room aging of 1-mm neat binder films at 60°C was equivalent to about 15 months in Texas Highway 21 after the early higher hardening rate period.
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U2 - 10.3141/1962-02
DO - 10.3141/1962-02
M3 - Conference contribution
AN - SCOPUS:33846490701
SN - 0309099714
SN - 9780309099714
T3 - Transportation Research Record
SP - 12
EP - 20
BT - Bituminous Materials and Nonbituminous Components of Bituminous Paving Mixtures 2006
PB - National Research Council
ER -