- Author
- Bisby, L. | Kodur, V. K. R. | Green, M.
- Title
- Modelling the Fire Behavior of FRP-Strengthened Reinforced Concrete Columns.
- Coporate
- National Research Council of Canada, Ottawa, Ontario
- Report
- NRCC-47027,
- Book or Conf
- Structures in Fire, 3rd International Workshop. Proceedings. May 10-11, 2004, Ontario, Canada, 10-11 p., 2004
- Keywords
- reinforced concretes | columns | fire behavior | structures
- Abstract
- Rehabilitation and strengthening of reinforced concrete (RC) structures have changed significantly in recent years, due in large part to the introduction of fibre-reinforced polymers (FRP) as economical and effective infrastructure materials. FRPs are currently gaining acceptance in a wide range of civil engineering applications, including the external flexural repair of RC beams and slabs, and axial strengthening and ductility enhancement of RC columns, both of which can be achieved by bonding FRP plates and sheets to the exterior of the members. To date, the use of FRP materials for repair of RC structures has been limited primarily to bridge and transportation structures, while relatively few large scale applications have been conducted in buildings. One major factor preventing the widespread use of FRP materials in buildings, where fire resistance criteria must satisfied, is the lack of information available on the fire performance of FRP materials in general, and on the overall behaviour of FRP-strengthened concrete members during fire. Since FRP materials are sensitive to the effects of elevated temperatures, there are a number of significant concerns that must be considered with respect to the fire performance of FRP-strengthened members. These concerns include strength and stiffness degradation at high temperature, and loss of bond. To address these concerns, an ongoing collaborative research project is being conducted by researchers at Queen's University, Canada, and the National Research Council of Canada in conjunction with various industrial partners, to study the effects of fire on concrete slabs, beams, and columns strengthened with externally-bonded FRP materials. This paper presents details and results of a numerical model developed to simulate both the heat transfer behaviour and load-carrying capacity of FRP-wrapped and insulated RC columns in fire. The model that has been developed is unique in that it accounts for the variation in thermal and mechanical properties of the columns' constituent materials with temperature, including FRP. In addition, the model accounts for the confining effect of a circumferential FRP wrap on the stress-strain characteristics of the concrete. The model's predictions are compared against results from full-scale fire tests and are shown to agree satisfactorily.