Structural performance assessment of concrete components based on fractal information of cracks

Abstract

Damage assessment of concrete components is of vital importance for ensuring the safety of civil structures. The occurrence and development of cracks in reinforced concrete components are highly related to the damage condition. Based on the fractal characteristics of concrete cracks, a rapid damage assessment method of concrete components using the index of Fractal Dimension ( FD ) was proposed in this paper. Damages in structural concrete components were first categorized into four empirical levels according to the so-called loading-ratio. Through image processing of the crack developments from previous studies of concrete beam and column members at different loading stages, database of crack FD versus loading-ratio for concrete beams and columns were separately built. Linear regressions correlating the crack FD s and the loading-ratios were then constructed and validated for concrete beams and columns, respectively. The loading-ratio can be predicted by the linear regression using new crack FD of the concrete component for damage assessment. The proposed method was applied to a lab-tested specimen of a reinforced concrete shear wall - beam assembly. Results show that the proposed fast structural performance assessment method is reliable for identifying potential damage levels in concrete components. • A new damage index called Fractal Dimension is proposed for damage assessment of concrete components. • An empirical relationship between fractal dimension of concrete surface cracks and damage level is constructed. • Fast damage assessment for concrete components is realized.