X-RAY CT-BASED MEASUREMENTS OF RATE EFFECTS INFRACTURE OF HIGH-PERFORMANCE CONCRETE
Published: 2023
Publication Name: Proceedings of the 11th International Conference on Fracture Mechanics of Concrete and Concrete Structures
Publication URL: https://doi.org/10.21012/FC11.092310
Abstract:
An experimental study was performed on different types of steel fiber reinforced concrete with the objective of measuring the changes in energy dissipation mechanisms as a function of loading rate and fiber alignment. 50-mm diameter split-cylinder specimens were prepared with steel fibers, steel wool fibers, and a combination of both. Specimens were loaded at two rates, from quasi-static to high rate servo-hydraulic. Each specimen was scanned using x-ray computed tomography (CT) both before and after loading such that internal damage could be measured. Crack measurements were made through a 3D analysis of load-induced crack area using a hybrid edge-detection/connected components analysis (macrocrack analysis). 3D digital volume correlation was applied to measure strains such that damage below the crack detection threshold could be inferred (microcrack analysis). Preliminary results showed that specimens loaded at a higher rate tended to show a higher degree of microcracking relative to macrocracking. However, this variation was of a similar order of magnitude to the variation obsrved due to differences in fiber alignment.