Acoustic Emission Monitoring of Chemically Bonded Anchors

Abstract

This paper presents a study on the use of acoustic emission (AE) to assess the structural soundness of concrete reinforced with chemically bonded anchors. The results of an experimental work based on six pullout tests monitored using an AE instrumentation suite are reported below. In every test one rebar was embedded in the hardened concrete by means of polyester resin. The AE was adopted to moni- tor the onset and progression of any structural damage. The parametric analysis, the intensity analysis and the moment tensor analysis of AE data were used to discriminate among different sources of damage. The technique shows promise for field application and may contribute to fully understand the structural mechanism in the rebar/adhesive/concrete sys- tems

Acoustic emission-based analysis of bond behavior of corroded reinforcement in existing concrete structures

“…These parameters can then be employed to construct damage intensity classification charts based on the acquired AE signal strength data. Intensity analysis was first applied in fiber-reinforced polymer vessels [36] and has also been utilized for the evaluation of various damage mechanisms of concrete structures [15,21,22,37]. The AE signal strength data recorded during the pull-out tests (after being filtered) were subjected to an intensity analysis to assess the bond behavior of corroded reinforcement to concrete in all specimens.…”

“…The analysis of the AE cumulative number of hits curves has previously been applied to evaluate the bond behavior [23] and to detect the different stages of bond damage in reinforced concrete [24]. On the other hand, the use of signal strength parameters (CSS, H (t), and S r ) has been found to be more sensitive in detecting various damage mechanisms in concrete structures-for example: [21,22,37,38]. To this end, the AE data (after being filtered) recorded throughout the pull-out test performed on sample 40A5-2 (as an example of all tested samples) are graphed in Figure 3.…”

“…AE sensors attached to the surface of the structure are sensitive to micro-cracking of concrete, which may be utilized to evaluate existing concrete structures. AE-based SHM systems have been employed to detect and identify a variety of damage mechanisms in both reinforced and prestressed concrete structures [15][16][17][18][19][20][21][22][23][24][25]. The application of AE monitoring has also been extended to monitor real concrete and masonry buildings [26] and multi-story reinforced concrete structures [27].…”

Microphones' directivity for the localization of sound sources

“…For comparative purposes, the localization of the speaker was also attained by comparing the differences among the time of arrival of the waves at the microphones. The authors have used this approach in the nondestructive evaluation method called acoustic emission [9]. The time of arrival ts,i of the wave at each microphone (s) can be written as:…”

Elastoplastic Damaging Model for Adhesive Anchor Systems. II: Numerical and Experimental Validation

“…In this study, AE results were analyzed by means of parameter analysis (Rizzo and Lanza di Scalea 2001;Lavrov 2001;Gostautas et al 2005;Matta et al 2006;Ranjith et al 2008;Degala et al 2009;Rizzo et al 2010) and moment tensor analysis (Landis and Shah 1993;Ohtsu 1995;Suaris and van Mier 1995;Guo et al 1997;Chang and Lee 2004;Ohno et al 2007;Rizzo et al 2010). The advantage of the first analysis is that it can be conducted by using one sensor only.…”