Application of Digital Image Correlation to Reinforced Concrete Fracture

Abstract

The fracture process in reinforced concrete structures is complicated because it is associated with the development of both micro cracks and major cracks. The fracture behavior is also connected to other phenomena including strain localization and crack bridging and depends on the heterogeneity of concrete, the type of reinforcement, and the concrete and reinforcement properties. The purpose of this study is to investigate the mode I crack propagation in reinforced concrete using Digital Image Correlation (DIC). DIC is a robust, non-contact and precise tool for fracture measurements. Digital images are taken at different loading stages and by comparing the images it is possible to infer the deformation of an object subjected to external loads. In this paper, the relationship between the fracture properties and the properties of the concrete and steel reinforcement is investigated experimentally. Tests were performed on small-scale reinforced concrete specimens in three point bending. By means of the DIC technique the visualization and quantification of the fracture properties of reinforced concrete could be determined. The DIC technique was found to be an effective mean to measure the crack opening displacements.

A Review of Surface Deformation and Strain Measurement Using Two-Dimensional Digital Image Correlation

“…In the last three decades, the DIC technique was used to study the deformation behaviour of various materials. For example, the full-field displacement analysis of composite cylinder, measurement of the surface profile of a plastic specimen under loading and examining specimens with heterogeneous deformation pattern were performed using the DIC technique [66,70]. Besides, various applications have been reported as the DIC technique was widely employed in many mechanical testing procedures.…”

Fracture process zone and tensile behavior of blended binders containing limestone powder

“…The corresponding mathematical formulations are described elsewhere [22,34]. The horizontal (u) and vertical (v) displacement fields in the analysis region were then computed by minimization of the correlation coefficient (C) [22,27,34]. The image processing and analysis operations were carried out using the commercial VIC-2D software™.…”

“…While several experimental techniques such as high speed photography [12], acoustic emission [13][14][15], scanning electron microscopy (SEM) [16][17][18][19], and laser-speckle interferometry [20,21] have been used to investigate FPZ in concretes, this study employs a non-contact digital image correlation (DIC)-based speckle-tracking method [10,[22][23][24][25][26][27][28] to assess the surface displacements and strains, and thus the width of the FPZ. The presence of soft(er) limestone particles and ductile clay phase (from metakaolin), which improves the fracture performance of multiple-material binders through improved inelastic energy dissipation [10], influences the FPZ, which is explored in detail.…”

Characterization of hydraulically bound base materials through digital image correlation

“…The use of this technique therefore enables measuring of an area full field deformation, which makes it useful for determining the collapse mechanism on various material specimens. With an insight into the whole deformation field it is possible to completely reconstruct the crack geometry without extensive instrumentation [16].…”