Grantee Research Project Results

Final Report: Recycled Materials for Repair and Rehabilitation of Aging Concrete Structures

EPA Contract Number: 68D01022
Title: Recycled Materials for Repair and Rehabilitation of Aging Concrete Structures
Investigators: Roylance, Margaret E.
Small Business: Foster-Miller Inc.
EPA Contact:
Phase: I
Project Period: April 1, 2001 through September 1, 2001
Project Amount: $69,987
RFA: Small Business Innovation Research (SBIR) - Phase I (2001) RFA Text | Recipients Lists
Research Category: Nanotechnology , SBIR - Pollution Prevention , Pollution Prevention/Sustainable Development , Small Business Innovation Research (SBIR)

Description:

This Phase I project sought to adapt and demonstrate Foster-Miller, Inc.'s existing ultrasonic tape lamination (UTL) technology from the fabrication of fiber-reinforced thermoplastic aerospace components to encapsulation of concrete columns to address the aging infrastructure issue with available technology. Exterior wrapping of concrete columns initially was developed for seismic reinforcement in high-risk areas such as California. As the technology has gained acceptance, it is being considered for use in other areas for extending column life, reducing corrosion, and preventing spalling. However, all existing composite-wrapping systems utilize some form of a fiber-reinforced thermoset material. This program focused on the use of UTL technology for in situ consolidation of fiber-reinforced recycled thermoplastics as a superior alternative.

The proposed Phase I project was conducted to adapt Foster-Miller's UTL technology to enable rehabilitation and repair of concrete columns with fiber-reinforced recycled plastic. The project was successfully completed and all of the objectives were met. The project targeted maintenance applications, although both structural and maintenance applications were identified in the commercialization plan prepared by Foresight Science and Technology. The primary function of column wrapping for maintenance is to prevent water intrusion and spalling from freeze-thaw cycles. A demonstration structure in Boston's Fenway area was selected, and site-specific requirements were identified. A Phase I technology demonstration was performed on a column of comparable size and concrete composition in preparation for an onsite demonstration during Phase II. During Phase I, a reliable source of postconsumer polyethylene terephthalate (PET) was identified, and fabrication of high-quality slurry-based E-glass prepreg was demonstrated from the recycled material. An alternate hot melt prepreg that promises improved affordability also was identified and will be pursued in Phase II. One hundred pounds of recycled E-glass/PET composite tape were obtained and 40 kHz processing trials on recycled material demonstrated excellent UTL seam bonding. A hand-held UTL frame was designed and built for use in field demonstrations. Using the portable UTL system, a 5-foot diameter cylindrical reinforced concrete structure was wrapped with the recycled composite and capped with a structure designed specifically for the Fenway column. The cap structure was prefabricated in the laboratory at Foster-Miller and installed using the hand-held 40 kHz unit.

Summary/Accomplishments (Outputs/Outcomes):

Table 1 lists the Phase I technical objectives and corresponding results.

Table 1. Summary of Phase I achievements.

Technical Objectives

Phase I Results

Define the performance requirements for a column encapsulation system.
Evaluate and secure the reinforced recycled plastic material supply chain.
Demonstrate?through process analysis, laboratory fabrication, and testing?that the necessary performance can be achieved.
Utilize the technology in an initial field application.
Design a practical ultrasonic-wrapping system for fabrication and use in Phase II.
Develop cost projections for welding unit and potential time and cost savings.

Identified both structural and maintenance applications. Targeted maintenance applications.
Primary maintenance function is to prevent water intrusion and spalling from freeze-thaw cycles.
Selected a demonstration structure and identified site-specific requirements.
Identified a reliable source of postconsumer PET.
Demonstrated fabrication of high-quality slurry-based E-glass prepreg from the recycled material.
Identified alternate hot melt prepreg for improved affordability
Performed 40 kHz processing trials on recycled composite.
Demonstrated excellent UTL seam bonding.
Demonstrated prefabrication of composite column cap structure.
Obtained 100 pounds of E-glass/PET composite tape.
Fabricated a hand-held UTL unit for use in field demonstrations.
Wrapped and capped a 5-foot diameter cylindrical reinforced concrete structure using recycled composite.
Hand-held UTL frame ready for field use.
Identified portable electronics as a goal in the Phase II program.
Established estimate of time required to wrap a full-scale infrastructure column based on Phase I demonstration.

Conclusions:

In summary, a reliable supply of postconsumer PET has been identified at a cost of $0.35 per pound that can be used to produce high-quality thermoplastic composite material. Several routes to tape production have been identified and will be explored further in the Phase II project. UTL bonding of this material in situ against the substrate of a concrete column structure was easily accomplished using ultrasonic parameters well within the reach of a simple, hand-portable unit. Based on these results, Foster-Miller and Branson propose to design and build a prototype ultrasonic field-deployable joining system and demonstrate its use in the field for installation of both hot melt and slurry-based recycled thermoplastic composite materials in cooperation with the Metropolitan District Commission.

Journal Articles:

No journal articles submitted with this report: View all 1 publications for this project

Supplemental Keywords:

environmental durability, infrastructure maintenance, postconsumer recycled materials., RFA, Scientific Discipline, Sustainable Industry/Business, cleaner production/pollution prevention, Sustainable Environment, Environmental Chemistry, Chemistry, Technology for Sustainable Environment, Civil/Environmental Engineering, Civil Engineering, Chemistry and Materials Science, Engineering, Environmental Engineering, Ultrasonic Tape Lamination (UTL), concrete, ultrasonic tape lamination, fiber reinforced recycled plastics, concrete , recycling

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