Nonlinear Finite Element Method Analysis of After Fire Reinforced Concrete Beam Strengthened with Carbon Fiber Strip

Concrete which is exposed to high temperature will experience strength degradation. This research obtained nonlinear Finite Element numerical model for Reinforced Concrete (RC) Beam after-fire and then strengthened with Carbon Fiber Strip on the flexural area. RC beam before the fire (NB), after fire (AFB) and strengthened after (CAFB) FEM model were compared with the actual experimental results. Using ATENA v.2.1.10 and GID as Pre-Processor, the crack patterns of the numerical model showed a good agreement with experimental results. Loading and displacement relationship also showed the same behavior. Stress and strain relationship of each RC beam also has been observed for each loading step. S-Beta element utilized on ATENA v.2.1.10 gave the excellent results on nonlinearity material behavior, especially for model NB and AFB. The value of stiffness obtained for AFB and CAFB in the experiment was higher than the sample from the numeric result namely 64% and 45%, while the ductility value obtained from the experiment was also smaller about 41%, and 17% in comparison to its numerical.