CLOSING IN ON APPROVAL

A lack of qualification criteria and design standards has hindered some engineers from using fiber-reinforced polymers (FRPs) to restore concrete structures. However, several organizations are leading the effort to give end users the support they need to exploit these adaptable materials. The California Department of Transportation (Caltrans) reached an agreement in 1995 with the Society for the Advancement of Material and Process Engineering (SAMPE) and the Aerospace Corporation whereby SAMPE would contract with suppliers to certify FRP systems as suitable for use in retrofitting California bridges. So far, four FRP systems have been fully certified for use in the Caltrans program: a heat-activated prepreg system, a system of prefabricated FRP shells, and two wet layup systems. The International Conference of Building Officials (ICBO) published the report, "Acceptance Criteria for Concrete and Reinforced and Unreinforced Masonry Strengthening Using Fiber-Reinforced, Composite Systems," also called AC 125, in 1997. The criteria establish minimum requirements for the issuance of ICBO Evaluation Service reports on FRP systems used to strengthen concrete and masonry structural elements. A third program, this one being developed by a committee of the American Concrete Institute (ACI), will give engineers yet another set of tools for using FRPs for concrete structures. In 1991, the ACI set up Committee 440--Fiber Reinforced Polymer Reinforcement. The committee and its associate task groups are developing guidelines that the end user can follow to aid in the selection, design, and installation of FRP systems for concrete strengthening, along with provisional design recommendations for concrete reinforced with FRP bars. The committee is also cooperating with the American Society for Testing and Materials to develop standard test methods tailored for FRP materials used in infrastructure. The U.S. Army Corps of Engineers' construction engineering research laboratories are pairing engineering analysis with large-scale testing to develop a guide specification for retrofitting unreinforced masonry walls with FRPs to lessen the risk of collapse during a seismic event. In addition, such organizations as the Federal Highway Administration and state departments of transportation are working with the American Society of Civil Engineers (ASCE) Civil Engineering Research Foundation to develop standards for FRP systems and move them into commercial use.

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  • English

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  • Accession Number: 00788887
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 12 2000 12:00AM