00211588

Component

http://onlinepubs.trb.org...s/hrr/1970/340/340-002.pdf

THE PURPOSE IS TO PRESENT A CASE FOR A SIGNIFICANT STRIPPING MECHANISM BASED ON THERMALLY INDUCED PRESSURE IN THE VOID WATER OF SATURATED ASPHALTIC-CONCRETE MIXTURES. ALTHOUGH OBSERVATIONS AND MEASUREMENTS ARE OBTAINED FROM ASPHALTIC-CONCRETE PAVEMENT AND LABORATORY SPECIMENS REPRESENTING TYPICAL ASPHALTIC CONCRETE IN SOUTHEASTERN IDAHO, THE MECHANISM COULD ALSO BE PREVALENT IN OTHER STATES. POSSIBLE QUANTITATIVE MECHANISM COULD ALSO BE PREVALENT IN OTHER STATES. POSSIBLE QUANTITATIVE MECHANISMS ARE OUTLINED FOR USING THE CONCEPT OF ACTIVATING VOID WATER PRESSURE AND RESISTING ADHESION STRENGTH. IT WAS FOUND THAT VOID WATER PRESSURES MAY DEVELOP TO 20 PSI UNDER DIFFERENTIAL THERMAL EXPANSION OF THE COMPACTED ASPHALTIC CONCRETE AND COULD EXCEED THE ADHESION STRENGTH OF THE BINDER-AGGREGATE INTERFACE. VOID WATER ENTRANCE TO THE INTERFACE WAS OBSERVED FOR ALL CASES OF STRIPPING IN THE FORM OF PINHOLES CONNECTED TO VOID FISSURES. THE VOIDS (OR FISSURES) ARE DEVELOPED IN THE COMPACTION PHASE OF ASPHALTIC-CONCRETE PRODUCTION AN ARE NORMALLY OF THE "CORRECT" SIZE TO ENABLE SATURATION. HOWEVER, THEY ARE STILL OF LOW ENOUGH PERMEABILITY TO ENABLE THE CREATION OF VOID WATER PRESSURES DURING TEMPERATURE CHANGE. THE PROBLEM DISCUSSED IS ONE OF THE MODERATELY WEAK ASPHALT- AGGREGATE INTERFACE, DEPICTING INSTANCES WHERE STATIC STRIPPING TESTS ARE NOT ILLUSTRATIVE OF STRIPPING POTENTIAL AND, CONSEQUENTLY, SOME INTERFACIAL STRESSING IS REQUIRED. /AUTHOR/

Paper sponsored by Committee on Effects of Natural Elements and Chemicals on Bitumen Aggregate Combinations and presented at the 49th Annual Meeting. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.

01410276

pp 13-28

1970

Highway Research Record

49th Annual Meeting of the Highway Research Board

Print

Appendices (1) ; Figures (9) ; References (12)

Asphalt concrete; Compaction; Field studies; Interfaces; Laboratory tests; Percent saturation; Pressure; Stripping (Pavements); Thermal expansion; Void ratios; Water

Highways; Materials

TRIS, TRB

Jun 29 1971 12:00AM

• AN INVESTIGATION OF ASPHALT-AGGREGATE ADHESION BY MEASUREMENTS OF HEATS OF IMMERSION
• GENERAL CONCEPTS OF ADHESION
• INTERFACIAL BEHAVIOR OF ASPHALTENES