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Virginia Tech

CFRP as Shear and End-Zone Reinforcement for Concrete Bridge Girders

Abstract

dc:description.abstract

Corrosion of reinforcing steel is a major cause of damage to bridges in the United States. A possible solution to the corrosion issue is carbon fiber reinforced polymer (CFRP) material. CFRP material has been implemented as flexural reinforcement in many cases, but not as transverse reinforcing. The CFRP material studied in this thesis was NEFMAC grid, which consists of vertical and horizontal CFRP tows that form an 8 in. by 10 in. grid. The use of NEFMAC grid as transverse reinforcing has not been previously investigated. First, the development length of NEFMAC grid was determined. Next, an 18 ft long 19 in. deep beam, modeled after prestressed Bulb-T beams, was created with NEFMAC grid reinforcement. The beam was loaded with a single point load near the support to induce shear failure. Beams were fitted with instrumentation to capture shear cracking data. Shear capacity calculations following four methods were compared to test results. Lastly, a parametric study with strut-and-tie modeling was performed on Precast Bulb-T (PCBT) girders to determine the amount of CFRP grid needed for reinforcement in the anchorage zone. This thesis concludes that NEFMAC grid is a viable shear design option and presents the initial recommendations for design methods. These methods provide a basis for the design of NEFMAC grid shear reinforcing that could be used as a starting point for future testing of full scale specimens. When designing with NEFMAC grid, the full manufacturer's guaranteed strength should be used as it is the average reduced by three standard deviations. AASHTO modified compression field theory provides the best prediction of shear capacity. For anchorage zone design, working stress limits for CFRP grids need to be increased to allow more of the strength to be implemented in design.

Degree

thesis:*
Name thesis:degree_name
Master of Science
Level thesis:degree_level
masters
Discipline thesis:degree_discipline
Civil Engineering
Department dc:contributor.department
Civil and Environmental Engineering
Grantor dc:publisher
Virginia Tech
Year dc:date.issued
2016

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Magee, Mitchell Drake
Chair dc:contributor.committeechair
  • Roberts-Wollmann, Carin L.
Committee members dc:contributor.committeemember
  • Moen, Cristopher D.
  • Cousins, Thomas E.

Subjects

dc:subject × 5

Rights

dc:rights
Statement dc:rights
  • In Copyright

Identifiers

dc:identifier.*
Dc Identifier Other
vt_gsexam:8208
OAI identifier oai:identifier
oai:vtechworks.lib.vt.edu:10919/71673

Chain of custody

source
Harvested from
Virginia Tech
Base URL
vtechworks.lib.vt.edu/oai/request
Last updated
2026-07-22
Source record
OAI-PMH GetRecord
related terms
citation

Magee, Mitchell Drake. CFRP as Shear and End-Zone Reinforcement for Concrete Bridge Girders. masters thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/71673