Paper number 1219

PERFORMANCE OF CONCRETE SYSTEMS REPAIRED USING FIBER REINFORCED PLASTICS

Oral Buyukozturk, Brian Hearing, and Oguz Gunes

Department of Civil and Environmental Engineerin
Massachusetts Institute of Technology
777 Massachusetts Avenue Cambridge, MA 02139 USA

Summary

The popularity of using fiber reinforced plastics (FRP) to repair deteriorated and deficient infrastructure is increasing around the world. However, influences of existing damage and environmental conditions on the integrity and durability of the repaired systems are not well known. These influences must be evaluated before safe, reliable, and durable repair of concrete systems with FRP is possible. This paper investigates performance of reinforced concrete systems retrofitted with FRP as influenced by existing damage parameters in the system. First, failure modes and design parameters of systems retrofitted with FRP materials are reviewed. The importance of damage conditions such as existing cracks in the concrete and deteriorated materials are discussed. Then, the influence of existing cracks in concrete beams is studied through an experimental program. The presence of cracks is shown to initiate debonding fracture well before the ultimate load of the system. A fracture mechanics based approach is used to analyze the bi-material fracture and delamination scenarios created at the concrete-adhesive-laminate interfacial region. Criteria based on energy release rate concepts are considered for the prediction of crack path and delamination process zone growth. From the testing and a numerical analysis, fracture parameters influencing the delamination process are identified and investigated. Possible influences of environmental loading conditions are examined. Finally, the influence of these issues on design and evaluation procedures of concrete systems repaired with FRP is discussed.

Keywords

composite laminate, retrofit, damage, cracking, environmental performance.