Detection of Frost-Resistance Property of Large-Size Concrete Based on Impact-Echo Method

Abstract

The dynamic elasticity modulus (E d ) is the most commonly used indexes for nondestructive testing to represent the internal damage of hydraulic concrete. Samples with a specific size is required when the transverse resonance method was used to detect the E d , resulting in a limitation for field tests. The impact-echo method can make up defects of traditional detection methods for frost-resistance testing, such as the evaluation via the loss of mass or strength. The feasibility of the impact-echo method to obtain the relative E d is explored to detect the frost-resistance property of large-volume hydraulic concretes on site. Results show that the impact-echo method can replace the traditional resonance frequency method to evaluate the frost resistance of concrete, and has advantages of high accuracy, easy to operate, and not affecting by the aggregate size and size effect of samples. The dynamic elastic modulus of concrete detected by the impact-echo method has little difference with that obtained by the traditional resonance method. The one-dimensional elastic wave velocity of concrete has a good linear correlation with the transverse resonance frequency. The freeze-thaw damage occurred from the surface to the inner layer, and the surface is expected to be the most vulnerable part for the freeze-thaw damage. It is expected to monitor and track the degradation of the frost resistance of an actual structure by frequently detecting the P-wave velocity on site, which avoids coring again.