Combination of acoustic emission and digital image correlation monitoring for wedge splitting tests on large concrete specimens

Acoustic emission (AE) and digital image correlation (DIC) techniques are combined to monitor wedge splitting tests performed on very large concrete specimens made of mass concrete mixture with 100 mm maximum aggregate size. It is shown that cumulative acoustic energy recorded by AE is closely correlated to cumulative fracture energy when only the acoustic events related to microcracking in the local fracture process zone (FPZ) are considered. A new post-processing methodology is presented for DIC, and allows to assess the evolution of the local fracture energy and the length of FPZ during the wedge splitting test. Application of this methodology on WS test results allowed to visualize the boundary effects only on the length of FPZ. Contrary to what was expected, the local fracture energy evolution does not seem to be affected by boundary effect.

Automated summary

In this study, acoustic emission and digital image correlation techniques were combined to monitor wedge splitting tests on large concrete specimens. The results showed that the cumulative acoustic energy recorded closely correlated to the cumulative fracture energy, specifically related to microcracking in the local fracture process zone. A new post-processing methodology for digital image correlation was also introduced to assess the evolution of local fracture energy and the length of the fracture process zone during the test. The boundary effects were found to only affect the length of the fracture process zone, contrary to the expectation that it would affect the evolution of local fracture energy.