In-field performance of geosynthetics used to reinforce roadway base layers

Research has been initiated by the Montana Department of Transportation to understand if and how geosynthetics can be used to reinforce roadway base course layers. This research, as currently planned, may involve the construction and monitoring of geosynthetically reinforced full-scale field test sections subject to real traffic loading. Stress, strain, moisture content and temperature sensors would be used to monitor performance of the test sections. The research is being conducted in phases. Initially, a literature review was conducted to establish a need for further research. With this need identified, the first phase of the research was initiated. This final report discusses the work performed under Phase I of the project. The objective of the Phase I research was to examine instrumentation proposed for use in the field test sections to be constructed under a subsequent phase of the project. This objective was accomplished by constructing a pilot test section with certain instruments placed on the geosynthetics and within the base course and asphalt concrete layers. These instruments were monitored for a 4 month period. Laboratory wide-width tension tests were performed on the geosynthetics used in the pilot test section for the purpose of comparing the measured strain from the instrument to the global strain experienced by the material. From this work, conclusions are made regarding the appropriateness of certain instruments and installation techniques for use in field test sections.