Debonding damage analysis in composite-masonry strengthening systems with polymer- and mortar-based matrix by means of the acoustic emission technique

Abstract

This is the postprint of a paper published as: Verstrynge, E., Wevers, M., Ghiassi, B., Lourenço, P. (2016 ABSTRACT: Different types of strengthening systems, based on fiber reinforced materials, are under investigation for external strengthening of historic masonry structures. A full characterization of the bond behavior and of the short-and long-term failure mechanisms is crucial to ensure effective design, compatibility with the historic substrate and durability of the strengthening solution. Therein, nondestructive techniques are essential for bond characterization, durability assessment and on-site condition monitoring. In this paper, the Acoustic Emission (AE) technique is evaluated for debonding characterization and localization on Fiber Reinforced Polymer (FRP)-and Steel Reinforced Grout (SRG)-strengthened clay bricks. Both types of strengthening systems are subjected to accelerated ageing tests under thermal cycles and to single-lap shear bond tests. During the reported experimental campaign, AE data from the accelerated ageing tests demonstrated the thermal incompatibility between brick and epoxy-bonded FRP composites and debonding damage was successfully detected, characterized and located. In addition, a qualitative comparison is made with digital image correlation and infrared thermography, in view of efficient on-site debonding detection.

A review on acoustic emission monitoring for damage detection in masonry structures

“…95 (height) x 210 (length) cm², and 20 cm thickness) under bending, and results were compared with several other strain monitoring techniques. Acoustic emission sensing has also been applied to assess the efficacy or durability of repair techniques for historical masonry, such as grout injection of multi-leaf masonry [35], and composites with polymer-or mortar-based matrices for externally bonded strengthening [61].…”

Crack monitoring in historical masonry with distributed strain and acoustic emission sensing techniques

“…The acoustic emission technique is a non-destructive fracture monitoring technique that allows the detection of a crack propagating within a material by detecting and analysing the high-frequency elastic waves produced by the fracture process itself [12]. Analysis of the received waveforms reveals the location and severity of the cracks while individual fracture modes emit signals with different characteristics, enabling the assessment of the dominant fracture mechanism [18][19][20][21][22]. When analysing the AE results, a parameter-based approach applies basic signal characteristics (such as number of AE hits, energy content or amplitude) to deduce information on the fracture process.…”

Debonding detection in a carbon fibre reinforced concrete structure using guided waves

“…The bond between the CFRP and the concrete member is critical in maintaining the effectiveness of the strengthening system [6,7]. However, the poor construction quality, aging, shrinkage of concrete, and deterioration due to moisture may cause debonding between CFRP and concrete surfaces [8]. These debonding should be detected at an early stage to ensure the structural integrity and safety of these composite structures.…”