This paper presents both experimental results and modelling of a highly corroded beam subjected to chloride environment to assess the performance of long-term corrosion damaged beams. A 26 year old corroded reinforced concrete beam exposed to chloride environment was tested along with a control beam of same age till failure. Cracking maps and corrosion maps were drawn for corroded beam. Also force displacement curves for both beams and stress strain curves for steel bars were drawn. From the results it appeared that corrosion has a significant impact on load carrying capacity and deflection of beams. The modelling approach using Macro Finite Element (MFE) shows a good agreement with experimental results in terms of load capacity, stiffness of the beam and ultimate deflection.