RE-CAST: Research on Concrete Applications for Sustainable Transportation Tier 1 University Transportation Center.

摘要

Fabric-reinforced-contentious-matrix (FRCM) and fiber-reinforced polymer (FRP) composites have emerged as novel strengthening technologies. FRCM is a composite material consisting of a sequence of one or more layers of cement-based matrix reinforced with dry-fiber fabric(s). Conversely, FRP consists of a sequence of one or more plies of unidirectional fibers embedded in organic resin. The primary objective of this project was an extensive material characterization of two pre-selected FRCM and FRP systems in order to investigate their basic constitutive behavior and durability. Material characterization is performed in compliance with established Acceptance Criteria (AC434 and AC125). Results from the characterization yield material properties that are considered in determining experimental, theoretical, and design ultimate capacities of strengthened members. FRCM and FRP were used for the strengthening of intentionally damaged AASHTO Type III prestressed concrete girders taken from I-81 overpass near Arcadia, VA. Experimental and theoretical analyses were performed to demonstrate the ability of these two repair methods to restore moment capacity compromised by the loss of four and eight 9.5-mm (3/8-in.) diameter prestressing tendons. All experimental work was conducted at Virginia Tech and reported in details elsewhere. This document presents some of the experimental findings and shows additional and original analytical considerations on the performance of the repaired girders. In particular, it offers a comparison between theoretical results according to AASHTO LRFD Bridge Design Specifications (2010) and experimental tests. Finally, design methodology including ACI 318 (2011), ACI 549.4R (2013) and ACI 440.2R (2008) are used to calculate design values that are compared to experimental values.