Investigation of the Curing Mechanism of Foamed Asphalt Mixes Based on Micromechanics Principles
Publication: Journal of Materials in Civil Engineering
Volume 22, Issue 1
Abstract
This study investigated the curing mechanism of foamed asphalt mixes. Various laboratory strength and stiffness tests were performed on mixes with various asphalt and portland cement contents, and the specimens were subjected to two relatively extreme curing conditions. It was found that portland cement enhances certain properties of foamed asphalt mixes by strengthening the mineral filler phase, with the curing mechanism similar to that of typical cement treated materials. The curing mechanism of foamed asphalt mastic is primarily related to water evaporation. The bonding between asphalt mastic and aggregate particles cannot fully develop until most of the water retained at the interface evaporates. This bonding, once formed, is only partially damaged by reintroduced water. This proposed mechanism was supported by observations of fracture faces on tested specimens. A long-term curing study confirmed the validity of this mechanism regardless of the curing duration. Standard curing procedures are proposed for use in project level mix design and evaluation based on the findings.
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Acknowledgments
The work presented in this paper was sponsored by the California Department of Transportation, Division of Research and Innovation, for which the writers are grateful. The writers also wish to thank their collaborators in the California Department of Transportation, and at the UCPRC. The results presented in this paper do not represent any standard or specification of the California Department of Transportation, and the opinions expressed are those of the writers alone. The support from the University of California Davis Sustainable Transportation Center Dissertation Fellowship for the micromechanical analysis is also gratefully acknowledged.
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Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 22 • Issue 1 • January 2010
Pages: 29 - 38
Copyright
© 2010 ASCE.
History
Received: Nov 9, 2008
Accepted: May 8, 2009
Published online: May 11, 2009
Published in print: Jan 2010
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