Elastic Wave Application for Damage Detection in Concrete Slab with GFRP Reinforcement

Abstract

The aim of the presented examination is condition-monitoring of GFRP-reinforced concrete structural members using elastic wave propagation. As an example, a deck slab is selected. The deck slab is made of concrete of the targeted C30/37 class under three-point bending. During loading cycles, the specimen is observed with a digital image correlation (DIC) system, which enables calculation of the strain field. The measuring setup consists of two Baumer 12.3 Mpx cameras with VS-1220HV lenses, combined in a Q400 system by Dantec Dynamics GmbH. Elastic waves are also measured based on signals recorded with PZT (lead–zirconate–titanate) sensors. Additionally, the typical crack-opening measurements are made. The appearance of a crack and its growth causes changes in both the shape and amplitude of the registered signals. However, the changes are not obvious and depend on the location of the sensors. Due to the impossibility of determining simple parameters with respect to disturbingly wide cracks, for damage detection, an artificial neural network (ANN) is applied. Perfect determination of the specimen’s condition (100% properly classified patterns) is possible based on whether the element is under loading or not.

Analytical Study of SH Wave Scattering by a Circular Pipeline in an Inhomogeneous Concrete with Density Variation

“…By substituting the displacement of incident waves and scattering waves into Equations (15) and ( 16), the stresses field in the infinite inhomogeneous concrete in the ζ plane can be obtained,…”

“…Many studies have focused on structural damage or defects in concrete. For instance, Ziaja [ 15 ] used elastic wave propagation to monitor the state of GFRP-reinforced concrete structural members. They used PZT (lead-zirconate-titanate) sensors to record the changing state of elastic waves caused by cracks and crack propagation in GFRP reinforced concrete structures, considering the material discontinuity caused by cracks and the influence of strain field on wave propagation.…”

An Influence of Actuator Gluing on Elastic Wave Excited in the Structure

“…Tracking the examples in the literature can show, that there is a lack of direct answers. In many articles, individual solutions are presented [11,13,[18][19][20][21]. Despite how interesting they are, they do not raise issues of sensor attachment influence on excited and registered signals.…”

Micromechanics and Ultrasonic Propagation in Consolidated Earthen-Site Soils

“…Elastic wave, as a nondestructive testing method, has been widely used in geotechnical, medical, biological, industrial, and other fields [5][6][7][8]. Ultrasound-based methods can detect the internal damage and deterioration of concrete [9][10][11][12] and evaluate its engineering characteristics such as thermal conductivity [13][14][15]. Prassianakis et al investigated the dynamic modulus of elasticity and the deterioration index of materials through ultrasonic detection [16].…”