The use of fiber reinforced polymer (FRP) bars in concrete structures is becoming as the best solution to the steel corrosion problem. However, the thermal incompatibility between concrete and FRP bars in the transverse direction that produces tensile stresses within concrete under high temperatures may cause splitting failure of concrete cover and consequently the reduction of durability and serviceability of concrete structures. Numerous experimental tests and analytical investigation were carried out on thermal effects on FRP reinforced concrete structures. Nevertheless, the finite element modeling of thermal behavior of FRP bars embedded in concrete is not more investigated. This paper presents a nonlinear numerical study using ADINA finite element software to investigate the effect of the ratio of concrete cover thickness to FRP bar diameter (c/db) on the distribution of transverse thermal deformations in concrete cover and FRP bars for an asymmetric problem using prismatic concrete beams reinforced with FRP bars submitted to high temperatures up to + 60 °C. The results of thermal deformations in FRP bars-reinforced prismatic concrete beams predicted from non linear finite element model are compared with those obtained from analytical model and experimental tests.