EXECUTIVE SUMMARY

Under contract with the Geotextile Division of the Industrial Fabrics Association International, Maxim Technologies, Inc. investigated the use, performance, and design considerations for asphalt membrane interlayer systems utilizing a nonwoven paving fabric. This is a widely used technology with more than 15,000 lane miles installed each year in North America. Although performance of the system has obviously sustained this amount of annual usage, very little controlled testing and scientific verification has been performed on the system since its inception 30 years ago. Maxim chose to investigate the paving fabric interlayer system by reviewing all available literature on the subject as well as by interviewing many experts who have worked with the system for years. Enough data was available on which to form a strongly backed technical opinion on the effectiveness of nonwoven paving fabric systems. The results of this “expert system” analysis of nonwoven paving fabrics are presented in this report and summarized in this executive summary of the report.

The literature review examined more than 200 reports on the use and performance of nonwoven paving fabric interlayer systems. This effort was followed by Maxim’s personal interviewing of over 50 expert users of the paving fabric system. This data collection also revealed a data base of over 100 pavement sections on which performance of the system was monitored. The data search found 4 principal end use applications of the nonwoven paving fabric system: 1) Paving fabric with a chip seal over unpaved roads and subgrades, 2) Paving fabric and chip seal over existing AC (Asphalt Cement Concrete) pavements, 3) Paving fabric and AC overlay over existing PCC (Portland Cement Concrete) pavements, and 4) Paving fabric and AC overlay over existing AC pavements. Most applications included an asphalt cement concrete overlay (Conditions 3 and 4) and the comments of this summary are based on those conditions.