Premium
The kinetics of carbonyl formation in asphalt
Author(s) -
Liu Meng,
Lunsford K. M.,
Davison R. R.,
Glover C. J.,
Bullin J. A.
Publication year - 1996
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690420417
Subject(s) - reaction rate constant , activation energy , kinetics , oxygen , asphalt , chemistry , thermodynamics , order of reaction , hardening (computing) , reaction rate , first order , chemical kinetics , materials science , organic chemistry , composite material , catalysis , physics , mathematics , layer (electronics) , quantum mechanics
The oxidation of asphalt is a major cause of pavement failure. The low‐temperature oxidation kinetics of 14 asphalts are presented. At constant temperature and oxygen presure, asphalt oxidation occurs in two stages: (1) a relatively rapid‐rate period, followed by (2) a long period of constant rate. Activation energies for the constant‐rate region vary from 64 to 109 kJ/mol, and reaction orders relative to oxygen pressure vary from 0.25 to 0.61. This variation in activation energy and reaction order leads to skepticism regarding the present practices of evaluating road‐condition asphalt‐hardening rates at a single elevated temperature and perhaps at an elevated pressure. The asphalts occur in essentially two groups, one at high values of both activation energy and reaction order and the other at low values of each. The data indicate the existence of an isokinetic temperature near 100°C. The degree of oxidation that occurs during the initial rapid‐rate region varies inversely with the oxygen reaction order of the constant‐rate region.