Recycled Concrete Aggregate Federal Highway Administration National Review
Summary of Virginia Recycled Concrete Aggregate Review
May 19-23, 2003
The Virginia Department of Transportation's (VDOT' s) strategy for the recycling and reuse of concrete aggregate tries to provide a neutral playing field for recycled and virgin aggregates. Recycled concrete aggregate (RCA) is not specifically mentioned in the VDOT strategic plan, and there are no conditions that mandate its use. However, statewide use of RCA is permitted. Virginia State's vision is to construct projects of quality materials to provide a continuous use of these materials in an effective roadway system.
VDOT has used RCA in base, sub-base, synthetic reefs, and embankments. One example of VDOT's use of RCA in sub-base aggregate is the I-66 project, which won the National Concrete Paving Award after completion. This project was a part of a $140 million reconstruction program on a section of Interstate 66 in Fairfax and Prince William Counties.
The following is a list of benefits that have been identified by VDOT and aggregate producers while using RCA:
- RCA is a viable material and there are written specifications for its use in highway construction.
- The unbound cementitious material in the RCA improves the strength in base and sub-base.
- VDOT has established an income tax credit on the purchase price of recycling machinery. Equipment must operate on a company's site and does not include mobile units.
- Life cycle cost analysis (LCCA) was performed for crack and seat versus rubblization, and determined that crack and seat was more economical.
- RCA is more economical especially in urban settings. This is attributed to the lower cost and higher yield per ton of RCA compared to natural aggregate, together with the lower transportation cost.
- The use of RCA provides a means for reusing concrete-producing facilities' washout material.
- The use of RCA provides a means to recycle concrete rubble.
VDOT and local aggregate suppliers have been using RCA for over 9 years and have overcome some barriers. A summary of VDOT' s and aggregate industry's experiences is provided below.
- Recommendations for compacting RCA when it is used in base and sub-base are:
- Compaction of RCA in base should be in a saturated state to aid in the migration of fines throughout the mix.
- Compaction of RCA should be performed with steel wheel rollers, because of minor amounts of steel are present in the base that cause problems when using rubber-tired equipment.
- Recommendations for reducing contamination of concrete rubble for processing into aggregate are:
- Inspection of dumping trucks.
- Limitation of the concrete rubble sources by aggregate producers.
- Improvement and adaptation of equipment in the processing procedures.
- Establishment of agreements on solid waste management practice, including RCA.
- Virginia Department of Waste Management and VDOT developed an executive compliance agreement that defines solid waste management practices during construction and repair of highways.
VDOT and aggregate suppliers are looking to gain additional experience or information in the following areas:
- Development of mix design parameters for cement treated base with RCA as aggregate.
- Impact of RCA on the water quality in watershed areas.
- Reduction of the uncertainty of incoming material consistency at plants (quality and quantity of product).
- Reduction of the variation of field density measures (proctor test) due to changes in recycled concrete material.
- Development of market research to define supply sources of material and market for the use of RCA.
- Diminishing of fear to use recycled material through education.
- Impact of RCA as a permeable base on filter fabric drainage.
- Risk analysis for the uses of RCA, including long-term performance and environmental impacts.
- Quality Assurance and Quality Control testing procedures for RCA.
- Laboratory tests to determine the quality of RCA.
- Reviewing of current specifications to enhance the use of RCA.
People in Attendance at Discussion Group
|Lorenzo Casanovafirstname.lastname@example.org||Program & Technology Engineer. FHWA. VA.|
|Bryan Cawleyemail@example.com||Materials Engineer. FHWA. IL.|
|Mike Giurannafirstname.lastname@example.org||U.S. EPA. Philadelphia, PA.|
|Jason Harringtonemail@example.com||Pavement Engineer. FHWA. Washington, D.C.|
|Connie Hillfirstname.lastname@example.org||Environmental Protection Specialist. FHWA. VA.|
|Chuck Lueddersemail@example.com||Pavement and Materials Engineer. FHWA. CO.|
|Cathy Nicholasfirstname.lastname@example.org||Construction and Materials Engineer. FHWA. WA.|
|H. Keith Moo-Youngemail@example.com||Representing Norfolk State University. VA.|
|Gina Gonzalezfirstname.lastname@example.org||Representing Norfolk State University. VA.|
|Roberto Fonsecaemail@example.com||Division Administrator. FHWA. VA.|
|Frank Geefirstname.lastname@example.org||Chief Engineer of Operations. VDOT.|
|Daniel Gwinneremail@example.com||Solid Waste Planning. DEQ.|
|Mal Kerleyfirstname.lastname@example.org||Chief Engineer for Program Development. VDOT.|
|Michael Murphyemail@example.com||Director, Division of Environmental Enhancement. DEQ. VA.|
|Irene Ricofirstname.lastname@example.org||Assistant Division Administrator. FHWA.VA.|
|Jeff Southardemail@example.com||Director of Planning and Environment. VDOT.|
|Russ Dudleyfirstname.lastname@example.org||Environmental Compliance Manager, VDOT.|
|Mike Fitchemail@example.com||Virginia Transportation Research Council. VA.|
|Performance, Design, Materials, & Research. May 20,2003.|
|Stanley L. Hite||stanley.hite@virginiaDOT.org||Assistant State Materials Engineer. VDOT.|
|David Kaulfers||david.kaulfers@virginiaDOT.org||Assistant State Materials Engineer. VDOT.|
|Steve Lanefirstname.lastname@example.org||Senior Research Scientist. Transportation Research Council. VA.|
|Larry Lundyemail@example.com||Concrete Program Engineer. Materials. VDOT.|
|Andy Mergenmeierfirstname.lastname@example.org||State Materials Engineer. VDOT.|
|Robert C. Edwardsemail@example.com||Construction Manager. VDOT.|
|Dan Listonfirstname.lastname@example.org||State Construction Engineer. VDOT.|
|Vince Mammanoemail@example.com||Field Operations Team Leader. FHWA. VA.|
|Jim Schmidtfirstname.lastname@example.org||Quality Assurance Manager. Koch. VA.|
|Keith Beasleyemail@example.com||Virginia Ready Mixed Concrete Association. VA.|
|Jim Holland||jholland@Titanamerica.com||Virginia Ready Mixed Concrete Association. Titan America. VA.|
|Jim Sissonfirstname.lastname@example.org||Waterway Materials, LLC. VA.|
|Randy Weingartemail@example.com||Luck Stone. VA.|
The following is a list of the materials that have been provided to the review team:
Virginia Department of Transportation Special Provision for Crushed Hydraulic Cement Concrete (CHCC), Section 208, (Use as Sub-base and Aggregate Base Material)
Executive Compliance Agreement, Virginia Department of Waste Management and Virginia Department of Transportation.
Department of Environmental Quality, "Guidance for the Certification of Recycling Machinery and Equipment for State Income Tax Credit." Sections 58.1-338, 58.1-439.7, and 58.1-439.8.
Virginia Department of Transportation. " VDOT's Use of Recycled Concrete on I-66." May 2003.
Virginia Specification for Artificial Reefs (TBA-Buddy)
The following is a list of sites visited:
The Luck Stone Aggregate facility located at Fairfax facility was visited. We observed the RC stockpile and two different products produced from the RC (minus 4"-plus 2" and 2" minus).