Assessment of the bending stiffness distribution in large 2D RC plates and slabs like-structures based on spatially distributed strain data for structural health monitoring

The study proposes a new method to assess the bending stiffness distribution in plate- and slab- like reinforced concrete (RC) structures based on spatially distributed strain data. Specifically, the study aims to provide an adequate structural interpretation of the readings, which infers the structural health. It is especially relevant for RC structures, that are designed to be cracked during their service life. To meet this goal the study correlates damage induced by cracks and curvature computed from strains to analyze 2D RC structures characterised by directional strains, and moment redistribution. The study also considered the installation possibilities and the limited and thus averaged strain data. To exclusively correlate changes in curvatures, by means of curvature index factors, and residual bending stiffness distribution, the study proposed an iterative identification algorithm. The paper demonstrates the effectiveness of the algorithm by numerical simulations of strain measurements and considers the various limitations of the adopted strain measurements along large 2D RC structures. It is presented that the procedure succeeds in localising the damaged regions and provides less accurate, but still contributive, assessment of their severity. Thus, the proposed method can support engineers in decision making regarding the structural health of the structure.