The transverse coefficient of thermal expansion of FRP reinforcing or prestressing elements can be 5 to 8 times higher than the corresponding value for concrete. This may create significant bursting stresses within the concrete under uniform temperature increase. To study the influence of the transverse thermal expansion of FRP reinforcement, a finite element model (FEM) analysis has been performed. Three basic cases have been studied to evaluate the behaviour of Arapree prestressing bars and strips. Both the Hoyer effect (wedge-shaped expansion of the prestressing elements in the anchorage zone) and the transverse thermal expansion were considered. As a result of the analysis it was found that the critical concrete cover equals 3.5 to 5 times the bar diameter depending on the concrete strength and the shape of the prestressing element.
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