Water in the pavement section is recognized as a major factor in pavement deterioration and early loss of pavement service life. In recent years, highway engineers have recognized the cost benefits of providing permeable bases to drain the pavement section. The important balance between drainability and stability has been found in new aggregate gradations and stabilizing materials for base courses. Construction engineers have also developed new techniques for placing and compacting permeable base material.

This project was developed to help State highway agencies and industry partners become more familiar with new techniques in permeable base and edgedrain system design and construction. It concentrates on the use of permeable bases with concrete pavements and consists of a workshop and a slide presentation, a design manual, and field construction technical assistance. It also incorporates a hydraulic demonstration model that presents the drainage rate of various aggregate materials used in road building, including permeable bases.

More than 40 workshops have been completed to date. In a future NHI course, the scope of the workshop portion of this project will be expanded to include retrofit edgedrains and drainage of flexible pavement. (See DP-87 Phase II, under Asphalt Pavement Design and Construction.)

Workshops are still available upon request. Participant Notebook provides design, construction, and maintenance guidance, for permeable bases and eyedrain system. Computer software is available from PCTrans, University of Kansas, and McTrans, University of Florida.

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HIGHWAYTECHNET   VIRTUAL EXPO   PAVEMENTS INDEX

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U.S. Department of Transportation
Federal Highway Administration