The use of fibre reinforced polymer (FRP) bars as a substitute for steel bars seems to be an effective solution for reinforced concrete structures in corrosive environments. The different coefficients of thermal expansion of concrete and FRP reinforcing bars may cause splitting cracks within the concrete under thermal loading and, ultimately, the failure of concrete cover.
The main objective of this research project is to study the thermal effect on the structural performance of FRP reinforced concrete elements particularly the failure mechanisms of concrete cover. Parameters such as the concrete cover thickness, the spacing between FRP bars, the diameter and type of FRP bars, temperature variations will be investigated through the proposed experimental and theoretical approach. The proposed research program will provide useful and practical Design tools to the Civil Engineering professionals and end-users.
The experimental program taking into account these parameters is:
Effect of the ratio of FRP bars-diameter to concrete cover thickness on the stress/strain distributions in concrete and FRP bars: 30 concrete cylindrical specimens reinforced with FRP bars, varying diameter of FRP bars and concrete cover, fabricated and tested under thermal loading from -30° C to + 70°C.
Effect of the spacing between FRP reinforcement in concrete : 54 concrete rectangular beam specimens reinforced with FRP bars, varying diameter of FRP bars and concrete cover, fabricated and will be and tested under thermal loading from -30° C to +70°C.
Thermal effect on the structural behaviour of FRP reinforced concrete slabs subjected to high temperature (+70°C) and also to low temperature (-30°C).
All specimens will be instrumented with electrical strain gauges and thermocouple wires to monitor deformations of concrete and FRP reinforcement as well as temperature. Theoretical analysis including numerical and analytical models, able to evaluate the critical concrete cover depending on the size of FRP bars and the temperature level, will be developed and validated with experimental results.
Thirty concrete cylindrical specimens reinforced with glass FRP bars were fabricated and tested under temperature increase from -30°C to +70°C.
Fifty four concrete rectangular beam specimens reinforced with glass FRP bars were fabricated and they are now under testing with temperature varying from -30°C to 70°C.
July 2004 : Conduct testing on rectangular beam specimens.
August-December 2004 : Fabrication and testing of concrete slabs reinforced with FRP bars under low and high temperature.
January-April 2005 : Analytical and numerical studies.
May-December 2005 : Writing of thesis and technical papers.