Mechanical behaviour of Frost-damaged Reinforced Concrete Structures

Paper in proceedings, 2007

The paper presents a methodology to analyze the mechanical behavior of reinforced concrete structures with an observed amount of freezing-damage at a given time. It is proposed that the effect of internal freezing damage can be modeled as change of material properties, and that surface scaling can be modeled as change in geometry. The change in material properties was examined, and it was found that relations between compressive and tensile strength commonly used for undamaged concrete could not be directly applied to freezing damaged concrete. A modified relation was suggested. The proposed methodology was tested on concrete beams affected by internal freezing damage, using non-linear finite element analyses based on frac-ture mechanics in the program Diana, and the results were compared with available experimental results. The results indicated that an uncertainty in the analyses was the Young’s modulus for damaged concrete, and that this influenced the results to a rather large extent.