Fiber reinforced polymers (FRP) have been widely used in retrofitting and strengthening of deteriorated or deficient reinforced concrete (RC) elements. A major concern about those systems is their performance under elevated temperature which limits the application of FRP for strengthening requirements. Fire protection of the strengthening FRP system can be made by applying an external coating layer of a thermal resisting material. In order to predict the fire performance of such insulated FRP-strengthened members and their efficiency, experimental investigations are required to be carried out for such elements under realistic fire conditions, which requires time and cost. This paper presents numerical modelling of RC beams strengthened with externally bonded FRP and insulated by a fire protection layer under elevated temperature specified by standard fire tests. The nonlinear time domain transient thermal-stress finite element analysis is performed using the general purpose software ANSYS 12.1 in order to study the heat transfer mechanism and deformation within the beam for fire conditions initiating at the bottom side of the beam. The finite element model accounts for the variation in thermal and mechanical parameters of the constituent materials such as concrete, steel reinforcement bars, FRP and insulation material with temperature. Application is made on an FRP-strengthened and insulated RC T-beam which has been experimentally tested in the published literature in order to verify the adopted modelling procedure. The obtained numerical results are in good agreement with the experimental results regarding the temperature distribution across the beam and mid-span deflection. The presented procedure thus provides an economical and effective tool to investigate the effectiveness of fire insulation layers when subjected to high temperatures and to design thermal protection layers for FRP strengthening systems that satisfy fire resistance requirements specified in building codes and standards.

Fiber reinforced polymers (FRP) strengthening systems are mainly used to retrofit existing and deficient structural members. The performance of such strengthened structures at elevated temperatures is a critical issue that threatens the safety of the structure. Published research includes experimental testing of reinforced concrete (R.C) beams strengthened using FRP and subjected to fire tests. However, there is a need for numerical tools that simulate the performance of these FRP-strengthened elements in case of fire. This research work presents numerical modelling and nonlinear analysis conducted to assess the performance of reinforced concrete beams strengthened with externally bonded carbon FRP sheets when subjected to standard fire conditions. Finite element model using the general purpose software ANSYS 12.1 is developed and validated with experimental results published in the literature by other researchers.The developed finite element model achieved good correlation with the experimental results. Further, application of the validated finite element model is extended into a parametric study to explore the influence of different variables on the performance of the FRP system when subjected to fire. Different aggregate types, moisture contents, concrete cover thickness, insulation material types and insulation material thickness are included in the study. The developed finite element model is thus regarded a valid and economical alternative to experiments for prediction of the performance of FRP strengthened and insulated R.C beams under fire conditions. Additionally, it can be used for estimation of the fire rating of such structures as well as for design of adequate fire protection layers. 220 of a thermal insulating material, typically gypsum products, was placed around the beam crosssection.Few studies in the published literature addressed numerical modelling to predict the performance of FRP-strengthened R.C members subjected to fire [11][12][13][14][15][16][17] and the heat transfer through the different insulation layers during fire exposure [18]. Therefore, more research work is needed to model efficiently the performance of FRP-strengthened structures under elevated temperatures, in order to enable the analyst and designers to accurately predict the fire endurance and design efficiently the thermal insulation layers for such structures.---231 cross-section throughout the elevated temperature time history. 2. The proposed model gives more accurate representation for mid-span deflection compared with published numerical results due to using shell elements for FRP, proper representation of the constituent materials used and the refined meshing used in the present model. 3. The developed models can be considered as an alternative solution for the time consuming and expensive fire testing. 4. Increasing insulation material thickness enhances the beam thermal response. 5. Mid-span deflection usually decreases with the increase of insulation thickness. 6. The concrete cover is a vital key element to protec...

It is evident that laminated reinforced composite are successfully prolonging the life of composites compared to particle and fiber type of reinforced composites method. The question on how these laminated composites take up the fatigue loading is crucial in order to give sound confident to industry replacing their design from metal to composites based. The lack of confident and uncertainties’ life of composites components become an issue to designer to shift from metal based to composites based especially when the design required to be done in short time. This review gives a clear picture the state of fatigue life modelling and the life prediction of laminated composites structures. The types of model are favorable when it is accurate, simple and required less input parameters. In the end, this review gives clear pictures on mechanism that involve and the fundamental of formula that available at present.