Sources: Regulatory Resources LLC, Westfield, Ind.; CP staff
Engineering and construction consultancy Regulatory Resources, along with the DOT Advisory Board it administers, have created an auditing program to certify the quality of structural concrete-grade fiber reinforced polymers (FRPs). Scheduled for early-2022 release, their FRP Quality Control Manual will serve as a guidance document for an auditing program currently under American Association of State Highway and Transportation Officials review.
The program will provide third-party certification of FRP reinforcement manufacturers for DOT engineers who want to include glass or carbon fiber bar in their concrete specifications, according to Regulatory Resources principal and DOT Advisory Board facilitator Richard Krolewski. At present, he notes, 14 state DOTs support the development and future use of the FRP QC Manual for establishing product providers lists. Agencies are receptive to composite reinforcement such as glass fiber reinforced polymer (GFRP), he adds, as the material is one-quarter the weight and twice the tensile strength of conventional rebar—and does not rust.
“Concrete corrosion from steel is an ongoing problem in infrastructure, especially in bridges and particularly in coastal communities where saltwater accelerates the damaging effects of corrosion. A certification program for suppliers will make it easier to specify FRPs for all types of infrastructure projects,” Krolewski affirms.
AASHTO is reviewing the FRP QC Manual for prospective National Transportation Product Evaluation Program (NTPEP) inclusion. A proposed NTPEP committee, co-chaired by DOT Advisory Board members Joseph Stillwell, P.E., Maine DOT Bridge Program fabrication engineer, and Cabell Garbee, P.E., North Carolina DOT material products engineer, would oversee evaluation of GFRP and carbon fiber reinforced concrete (CFRC).
“Developing an auditing program for GFRP and CFRC will create an even playing field for all manufacturers,” Stillwell observes. “Third-party lab testing will give an unbiased assessment of the bar or strand, [and] states more confidence that the materials being provided will meet their requirements and be high-quality products.”
Regulatory Resources will assist pilot audits in the coming months at facilities supplying FRP material for a demonstration project currently being monitored by the North Carolina DOT. The Harker’s Island Bridge replacement is a single-span design succeeding a double-span crossing and will exclusively use FRP reinforcement, according to Garbee. “We are excited about this unique opportunity to put composite reinforcement elements at the forefront and create a very innovative, sustainable opportunity for NCDOT and the industry,” he adds.
Garbee and Stillwell are among 11 state transportation agency officials comprising the DOT Advisory Board, advisers to which represent FRP producers Owens Corning Infrastructure Solutions and Tuf-Bar Inc. (GFRP) and Tokyo Rope (carbon fiber).