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Research and Development (R&D) Project Sites

Project Information
Project ID:   FHWA-PROJ-09-0056
Project Name:   Geotextile Separation Layer for Aggregate Base Courses
Project Status:   Temporarily Suspended
Start Date:  October 1, 2009
End Date:  December 31, 2012
Contact Information
Last Name:  Gibson
First Name:  Nelson H
Telephone:  202-493-3073
E-mail:  nelson.gibson@dot.gov
Office:   Office of Infrastructure Research and Development
Team:   Pavement Materials Team [HRDI-10]
Program:   Innovative Pavement Research and Deployment
Laboratory:   Pavement Testing Facility
Project detail
Roadmap/Focus area(s):   Infrastructure Research and Technology Strategic Plan and Roadmap
Project Description:   The motivation for this research activity is to protect lower volume roads which may become higher volume roads and experience increased truck traffic loads and volumes.  The Accelerated Pavement Testing Facility at present cannot be used for such testing due to concerns with disturbing the site and adversely impacting existing Accelerated Pavement Testing experiments. Test pits are available with loading frames for conducting this research. The test pits are very attractive due to their large size, ability to instrument the site, and, more importantly, the ability to control saturation and water table level. Proposed is the development of a very low-cost repeated loading system to quantify performance and cost benefits from using a geotextile as a separation layer to keep subgrade fines and a high quality granular base from migrating and contaminating. The test pits would afford the opportunity to have a more robust research program than using the Accelerated Pavement Testing Facility, as more material and variable thickness can be readily constructed and tested.
Goals:   This project will gather saturated and unsaturated full-scale performance properties with and without separators to define particular changes in engineering properties for performance simulations to develop life-cycle cost analyses.
Product Type:   Data
Research report
Expected Benefits:   Benefits include quantifying the relative increase in life from both a stiffness and contamination standpoint provided by a geotextile separation layers in vulnerable subgrades/locations. The benefit to the highway community would be a more resilient pavement design for lower volume roads expected to become larger volume roads to be compatible with any long-term regional transportation needs.
Deliverables: Name: Life-cycle cost analyses.
Product Type(s): Research report, Data
Description: Example life-cycle cost analyses will be completed using mechanistic-empirical pavement simulations based on the accelerated pavement test performance.
FHWA Topics:   Roads and Bridges--Pavement and Materials
TRT Terms:   Geosynthetics
Granular Bases
FHWA Disciplines:   Pavement and Materials
Subject Areas:   Pavements


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