Behavior of Asphalts During Production of Asphaltic Concrete Mixes, HR-107, 1965

(1965) Behavior of Asphalts During Production of Asphaltic Concrete Mixes, HR-107, 1965. Transportation, Department of

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Abstract

When mixing asphalt in thin film and at high temperatures, as in the production of asphalt concrete, it has been shown that asphalt will harden due essentially to two factors: (1) losses of volatiles and (2) oxidation. The degree of hardening as expressed by percent loss in penetration varied from as low as 7% to about 57% depending on mixing temperatures, aggregate types, gradation, asphalt content, penetration and other characteristics of asphalts used. Methods used to predict hardening during mixing include loss on heat and thin film oven tests, with the latter showing better correlation with the field findings. However, information on other physical and chemical changes that may occur as a result of mixing in the production of hot-mix asphaltic concrete is limited, The purpose of this research project was to ascertain the changes of asphalt cement properties, both physical and chemical, during mixing operation and to determine whether one or more of the several tests of asphalt cements were critical enough to indicate these changes.

Item Type: Departmental Report
Keywords: Asphalt cement, Asphalt hardening, Chemical reactions, Hot mix asphalt, Instruments for measuring specific properties, Oxidation, Reactions in asphalt
Subjects: Transportation > Pavements
Transportation
Transportation > Roads and highways
Transportation > Research
Transportation > Research > Asphalt
ID Code: 17272
Deposited By: Iowa DOT Library
Deposited On: 30 Jun 2014 12:36
Last Modified: 22 Sep 2014 11:45
URI: http://publications.iowa.gov/id/eprint/17272