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原文传递 Repair of the Uphapee Creek Bridge with FRP Laminates. Final rept.

题名：	Repair of the Uphapee Creek Bridge with FRP Laminates. Final rept.
作者：	BARNES, R. W.; CARMICHAEL, B. M.
关键词：	Highway-bridges; Maintenance-; *Composite-materials.;Carbon-fiber-reinforced-plastics; Alabama-; Loads-Forces.
摘要：	This report describes the strengthening of a fifty-year-old, reinforced concrete bridge using externally bonded, fiber-reinforced polymer (FRP) strips. The three-span, continuous structure is supported by four variable-depth girders. The flexural capacity of each span of the existing structure was insufficient to withstand modern traffic loads. Carbon-fiber-reinforced polymer (CFRP) strips were externally bonded to the girder soffits to enhance the positive moment capacity of each span. The CFRP strengthening system was designed according to ACI 440 recommendations. The report details the installation process as well as a load-testing program utilized to assess the effectiveness of the strengthening system. The installation process was found to be rapid and simplebut exceedingly messy. The structure was load tested on several occasions: once prior to strengthening, once soon after installation of the CFRP, and twice approximately six months after strengthening. The bridge instrumentation measured girder deflections as well as strains in the steel and FRP tension reinforcement. A finite-element model of the bridge was developed to predict theoretical strains for comparison with experimental values. Good agreement was obtained between the experimental and theoretical steel strains in the structure. The reduction in steel strains attributable to the CFRP system corresponded well with the reduction predicted using linear-elastic, cracked-section analysis. Overall, the strengthened bridge behaved as predicted when subjected to truck loads slightly exceeding service-level design loads. The design of the FRP strengthening system is detailed in a companion interim report. Another companion report describes a laboratory test program to investigate the ultimate strength of the CFRP-strengthened girders as well as the effects traffic loads applied during the installation and epoxy-curing period.
报告类型：	科技报告