Field Demonstration of Foamed Asphalt Muscatine County, HR-257, 1988

(1988) Field Demonstration of Foamed Asphalt Muscatine County, HR-257, 1988. Transportation, Department of


File Size:1MB


The foamed asphalt concept has been around since the 1950's. Rising oil prices have created a renewed interest in this process. The purpose of this project was to construct an asphalt base using the foamed asphalt process and to evaluate its performance. A 4.2 mile length of Muscatine County road A-91 was selected for the research project. Asphalt contents of 4.5% and 5.5%, moisture contents of 70% and 90% of optimum, and fog, single chip, and double chip seal coats were used in various combinations to lay 9 test sections of 4-inch foamed asphalt base. After five years of service and evaluation, several conclusions can be made concerning the performance of the foamed asphalt bases: (1) the foamed asphalt process can work as shown by the excellent performance of Sections 2 and 3; (2) foamed asphalt base requires a well compacted subgrade and a road profile suitable for good drainage of water--test section failures were mostly due to a poor subgrade and subsurface moisture; and (3) when the base is placed in two or more lifts, extreme care must be exercised to insure adequate bonding is achieved between lifts. Any future research with foamed asphalt should include various asphalt depths in order to determine a thickness/strength relationship for foamed asphalt.

Item Type: Departmental Report
Keywords: Asphalt content, Base course (Pavements), Bonding, Chip seals, Field tests, Foamed asphalt, Future, Moisture content, Performance evaluations, Research, Seal coats, Soil water, Subgrade (Pavements), Test sections, Future research
Subjects: Transportation
Transportation > Roads and highways
Transportation > Research
ID Code: 16013
Deposited By: Iowa DOT Library
Deposited On: 03 Feb 2014 14:40
Last Modified: 22 Sep 2014 11:42