A study on the bond capacity of fibre reinforced polymer (FRP) bars in concrete at elevated temperature is presented. By understanding the effects of temperature on the polymer resin matrix and on the FRPs’ tensile and bond properties, and by rationally optimising the placement and anchorage of the bars, FRP reinforcements may be designed as fire-safe alternatives to steel reinforcement for concrete. However, this requires an understanding of the critical issues for FRP that could cause structural collapse under service loads during fire. The investigation presented in this paper includes determination of the glass transition temperature (Tg) of two commercially available, FRP reinforcing bars using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). Reductions in bond strength of these FRP bars at elevated temperature are also presented using steady-state bond pullout tests. It is shown that bond strength reduces at elevated temperature in the region of the lowest Tg value, determined using various possible test methods and definitions. The presented data are useful in making rational assessments of the likely structural fire resistance of FRP reinforced concrete elements, and will be used in analysis and interpretation of upcoming large-scale fire tests on FRP reinforced concrete slabs.
|Title of host publication||7th international Conference on Fiber Reinforced Polymer (FRP) Composites in Civil Engineering (CICE 2014)|
|Place of Publication||Vancouver|
|Number of pages||6|
|Publication status||Published - 1 Aug 2014|