Title:
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Acoustic emission techniques for the damage assessment of reinforced concrete structures
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This thesis examines the role of Acoustic Emission (AE) techniques as a nondestructive
testing (NDT) technique for reinforced concrete structures. The
work focuses on the development of experimental techniques and data
analysis methods for the detection, location and assessment of AE from the
reinforced concrete specimens. Three key topics are investigated:
1. Method of analysis for laboratory-based pre-corroded and postcorroded
reinforced concrete specimens tested in flexure.
Experimental results from a series of laboratory studies are presented. The
work investigates the changing behaviour of the reinforced concrete beams
due to chloride-induced reinforcement corrosion by using a parameter-based
approach to detect, locate and follow the progression of cracks. The use of
AE absolute energy as an indication of concrete cracking is also explored.
2. A practical investigation into acoustic wave propagation in
reinforced concrete structures.
Experimental results from acoustic wave propagation of two source modes
(parallel and normal to sensor face) are presented. The work investigates the
wave velocity in concrete structures over a variety of source-to-sensor
distances with the influence of pre-set threshold levels. Specimen geometry,
specimen conditions and source orientation is explained. The application of
modal behaviour on the AE from both artificial and real sources is examined.
Experimental data describing signal attenuation is also presented.
3. The detection of damage within an in-service concrete crosshead.
Further analysis of a commercial bridge inspection is given. A comparison of
results from both clustered and non-clustered events, with laboratory based
results is made. Apart from being interested with clustered events, nonclustered
events are also an important contribution to damage detection in
structural monitoring.
Key Words: Acoustic Emission, Corrosion, Reinforced Concrete, Concrete
Cracks, Source Location, Wave Propagation, Damage Assessment, Bridge
Monitoring.
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Keywords: |
Acoustic Emission, Corrosion, Reinforced Concrete, Concrete Cracks, Source Location, Wave Propagation, Damage Assessment, Bridge Monitoring
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