PMSS Project Details

Project ID:	FHWA-PROJ-11-0014
Project Name:	Characterization of Open-Graded Aggregates
Status:	Active
Contact:	Last Name: Nicks First Name: Jennifer E Telephone: 202-493-3075 E-mail: jennifer.nicks@dot.gov
Organization:	Federal Highway Administration - Turner-Fairbank Highway Research Center (TFHRC)
Office:	Office of Infrastructure Research and Development
Team:	Bridge and Foundation Engineering Team
Roadmap/Focus area(s):	Not Applicable
Project Findings:	Data not yet available
Project Description:	This project will characterize natural aggregates based on the American Association of State Highway and Transportation Officials (AASHTO) Designation: M43-05 (and the American Society for Testing and Materials (ASTM) Designation: D 448-03a). State Department of Transportation (DOT) Agencies and counties use this designation (or an equivalent) to specify the aggregates used in the construction and maintenance of highways and bridges (e.g. the Geosynthetic Reinforced Soil Integrated Bridge System). To accurately obtain the strength properties of these materials, a large-scale test device, such as a large shear box or a large diameter triaxial cell, must be used. Many transportation agencies do not have access to these large-scale devices and often use a scalped sample or a default low value for the friction angle, leading to a conservative design. This project will provide engineers with more accurate friction angles for their commonly used materials. Since the friction angle is based on other factors besides gradation and size, the influence of saturation, angularity, and maximum density will also be investigated. A correlation to the repose angle of the materials will also be developed so that a designer can more accurately estimate the friction angle of granular material without performing a large-scale direct shear test. To date, this characterization of the AASHTO open-graded aggregates has not been performed. Future work includes characterization of common well-graded aggregates. The results of this applied research will immediately benefit transportation agencies.
Laboratories:	Geotechnical Laboratory
Start Date:	March 1, 2011
End Date:	August 31, 2012
Funding Amount:	$0.00
FHWA Program Name:	Turner-Fairbank Highway Research Center
Goals:	The objectives of this research are threefold: 1.) provide engineers with the strength properties of the common open graded aggregates used in construction; 2.) describe the influence of saturation, angularity, and density on the strength of common aggregate blends; and 3.) correlate the friction angle with the repose angle or other soil properties, if possible.
Project Type:	Onsite
Background Information:	Data not yet available
Test Methodology:	Laboratory testing
Other Information:	Data not yet available
Partners:	Data not yet available
More Information URL(s):
Fieldtest:	Data not yet available
Expected Benefits:	This research will provide transportation agencies (e.g. DOTs) with strength properties of commonly used open graded aggregates.
Deliverables:	Name: Research Report Product Type(s): Other Description: The deliverable will be a research report outlining the strength properties of the American Association of State Highway and Transportation Officials (AASHTO) aggregates. Recommendations will also be provided on the use of large scale direct shear tests. Audiences: Researchers, Hydraulic and geotechnical engineers, State highway agencies, Federal Turner-Fairbank Highway Research Center staff, Metropolitan planning organizations Secondary Audiences:
Related URL(s):
FHWA Topics:	Research/Technologies--Turner-Fairbank Highway Research Center (TFHRC) Roads and Bridges--Design
TRT Terms:	Transportation Test procedures Design Materials
FHWA Disciplines:	Design Geotechnical Pavement and Materials
Subject Areas:	Bridges and other structures Design Geotechnology Highways Materials Pavements Research Transportation (General)