Numerical analysis of thermal stress-deformation in concrete surrounding FRP bars in hot region

The transverse thermal incompatibility between fiber reinforced polymer (FRP) bar and concrete generates radial pressure, at FRP bar/concrete interface, that may cause splitting cracks within the concrete under temperature increase and, ultimately, failure of the concrete cover. This paper presents a non-linear finite element analysis using ADINA Software to investigate transverse thermal deformations and stresses through concrete cover surrounding FRP bars under high temperatures up to +60 °C varying the ratio of concrete cover thickness to FRP bar diameter (c/db). This investigation allows to determine the temperature increase (ΔTcr) producing the first radial crack in concrete at the interface and the temperature increase (ΔTsp) producing splitting failure of the concrete cover. Comparisons between numerical, analytical, and experimental results are presented.