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Title:

UNDERCLAY DEVELOPMENT BENEATH ASPHALT ROADS IN KANSAS

Accession Number:

00231353

Record Type:

Component

Abstract:

LOESSIAL SUBGRADE MATERIALS IN CONTACT WITH ASPHALT ROAD SURFACES IN KANSAS ARE UNDERGOING CHANGES IN STRUCTURE, COLOR, AND AMOUNT OF LESS THAN 2-U CLAY. STRUCTURE IS CHANGING FROM MASSIVE OR SINGLE GRAIN TO WEAK SUBANGULAR BLOCKY. COLOR IS CHANGING FROM A PALE BROWN (10YR 6/3) OR LIGHT BROWNISH GRAY (10YR 5/3) TO A GREEN OR OLIVE GREEN THAT IS USUALLY A 5Y HUE IN THE OLIVE GRAY RANGE, BUT THE COLORS APPEAR GREEN TO THE EYE. THE AMOUNT OF LESS THAN 2-U CLAY IS INCREASING. THE CHANGES ARE CAUSED BY MICROORGANISMS UTILIZING THE ASPHALT AS AN ENERGY SOURCE. REDUCING CONDITIONS ARE SET UP AT THE SOIL-ASPHALT INTERFACE BY THE ACTIONS OF THE MICROORGANISMS WHERE THE SUPPLY OF AIR AND OXYGEN IS LIMITED. THIS RESULTS IN A GLEY OR 'UNDERCLAY' DEVELOPMENT IN THE UPPER FEW INCHES OF SUBGRADE SOIL. MONTMORILLONITE CLAY IS DEVELOPING FROM PRIMARY MINERALS IN THIS ZONE. KAOLINITE IS IMPROVING IN CRYSTALLINITY IN THIS HORIZON. OXIDIZING MICROENVIRONMENTS IN A REDUCING MACROENVIRONMENT PROBABLY ACCOUNTS FOR THE IMPROVEMENT OF KAOLINITE CRYSTALLINITY UNDER CONDITIONS THAT FAVOR THE FORMATION OF MONTMORILLONITE. DIFFERENCES IN PROPERTIES OF SUBGRADE MATERIALS BETWEEN FAILED AND ADJACENT NON-FAILED SECTIONS OF ROADWAY ARE NOT GREAT. OXYGEN UPTAKE RATES, HOWEVER, SHOW THAT FAILING SECTIONS OF ROAD HAVE HIGH OXIDATIVE ACTION OF MICROORGANISMS COMPARED TO NON-FAILING SECTIONS. /AUTHOR/

Supplemental Notes:

Paper sponsored by Committee on Environmental Factors and presented at the 47th 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.

Monograph Accession #:

01410163

Language:

English

Authors:

Crumpton, Carl F
Badgley, William A

Pagination:

pp 24-34

Publication Date:

1968

Serial:

Highway Research Record

Issue Number: 215
Publisher: Highway Research Board

Media Type:

Digital/other

Features:

Figures (4) ; References (33) ; Tables (1)

Old TRIS Terms:

Subject Areas:

Geotechnology; Highways

Files:

TRIS, TRB

Created Date:

Aug 15 2004 2:41AM

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