Practical approach to structural assessment of reinforcement in existing concrete structures affected by corrosion or fire

Many buildings and structures of (reinforced) concrete reach ages of 50-100 years, and over the lifespan, they can change their function. In some cases, structural assessments should be conducted to guarantee the structure’s safety. Therefore, the material parameters of old construction materials need to be considered. For existing structures, it can be challenging to determine the quality of the reinforcement employed. Furthermore, owing to degradation (e.g. corrosion or fire), the section of rebars and their mechanical parameters can be affected. This research explains how to determine the initial reinforcement quality based on historically available data in Belgium. In addition, the effect of corrosion and high temperatures has been investigated by means of an experimental program on cold-formed dented bars and ribbed Tempcore bars. Based on tensile tests on heated and induced corroded rebars, it was found that both strength and ductility were affected. However, different effects were seen for cold-formed bars versus Tempcore bars with a composite cross-section. Finally, recommendations have been formulated for assessing existing reinforced concrete structures exposed to corrosion or fire.