Linear and nonlinear resonant ultrasonic techniques applied to assess delayed ettringite formation on concrete samples

This study investigates the application of different ultrasonic Non-Destructive tests to assess Delayed Ettringite Formation, in concrete samples exhibiting low kinetic expansions (and up 0.21%). Linear and nonlinear Resonant Ultrasonic Spectroscopy Acoustic Emission were used. Scanning Electron Microscopy optical microscopy observations conducted at end monitoring tests. The results showed a slight increase dynamic modulus Quality factor while hysteretic parameters remained constant over test duration. attested occurrence events. However, microscopic did not reveal meaningful differences microcracking extent between samples.