WTI

Developing A Standard Test Method for Measuring Geosynthetic-Soil Resilient Interface Shear - UTC

Primary Investigator Contact Information

External Project Contact(s)

Report(s)

There are no reports associated with this project.

Project Objective

Establish specific test protocols to determine parameters pertinent to geosynthetic reinforced pavement design. These testing protocols will be used to establish best practices for conducting cyclic pullout tests such that these protocols can be incorporated into American Society for Testing Materials (ASTM) testing standards.

Project Abstract

When geosynthetics are used to reinforce the base course layers of flexible pavements, one of the main design parameters is the interaction between the geosynthetic and the surrounding aggregates. The most relevant interaction tests use cyclic loads like those experienced in transportation applications. Currently there is no standard test to quantify soil/geosynthetic interaction using cyclic loads. Eli Cuelho and researchers working in the Materials Laboratory at WTI are striving to establish specific test protocols pertinent to geosynthetic reinforced pavement design. These protocols will be used to establish best practices for conducting cyclic pullout tests so that these protocols can be incorporated into American Society for Testing Materials (ASTM) testing standards, and so be used with consistency by testing laboratories. The anticipated benefits for state transportation departments include development of performance-based specifications for geosynthetic products used in pavement reinforcement applications, and the establishment of testing methods that can be referenced when incorporating reinforced pavement design into a national mechanistic-empirical design guide.

Task Descriptions

1. Reporting and Technology Transfer
   1. Compile results into a final report and disseminate through a technical conference paper, and through the Task Group on Subgrade Reinforcement of the ASTM D35 Committee on Geosynthetics.
2. Conduct Cyclic Pullout Tests
   1. Run series of laboratory tests to establish standard test protocols.
3. Update Laboratory Equipment
   1. Modify current pullout test facility to accept the new servo-hydraulic load and control system. Update instrumentation and data acquisition equipment.
4. Literature Review
   1. Review all literature relevant to the subject to refine direction and document past research work related to cyclic and static pullout tests, as well as other literature that deals with soil-geosynthetic interaction parameters.
5. Analyze Results
   1. Analyze and synthesize all results to determine optimum confining soil, necessary number of cycles per load step, optimum number of combinations of normal stress and cyclic shear stress, optimum length of sample embedment, and optimum sample gripping method.

Milestones, Dates, Schedule

Student Involvement

True

Relationship to Other Research Projects

False

Technology Transfer Activities

True

Transportation Research Board Keywords

geosynthetics, pullout, test protocol, cyclic, stiffness

Partners

Christopher Consultants, NAUE GmbH & Co. KG