Nonlinear Impact-Echo Test for Quantitative Evaluation of ASR Damage in Concrete

Abstract

Nonlinear acoustic methods demonstrate high sensitivity for concrete damage evaluation. Among these methods, nonlinear resonance acoustic methods have been widely used in laboratory tests on small scale test samples. In this study, a nonlinear impact-echo (IE) method was proposed for concrete damage evaluation, in which the IE frequency shift was measured at different impact force levels. The nonlinear IE test is similar to the nonlinear impact resonance acoustic spectroscopy (NIRAS) test in the experimental setup and analysis method. However, the nonlinear IE test excites a local thickness resonance mode of a member instead of the global resonance vibration. Therefore, the analyzed mode is not affected by boundary conditions and can be applied to large concrete structural members. To identify the fundamental IE frequency, multiple impacts at different locations were used. The nonlinear IE method was then validated on seven concrete beam specimens with different levels of alkali-silica reaction (ASR) damage. The nonlinear IE test results demonstrate high sensitivity to concrete damage and allow for quantitative assessment of the damage state of concrete without a baseline measurement.

Assessment of Machine Learning for Ultrasonic Nondestructive Evaluation of Alkali–Silica Reaction in Concrete

“…As ASR progresses, the amplitude and velocity of ultrasonic waves propagating through the concrete decrease while the wave attenuation increases. Multiple studies have implemented ultrasonic NDE for long-term monitoring of the ASR damage development in concrete and have proven the success of ultrasonic testing techniques for assessing a concrete structure that has developed ASR damage [2], [7], [8], [9], [10].…”