Title:
Monitoring damage in concrete using diffuse ultrasonic coda wave interferometry

dc.contributor.advisor Jacobs, Laurence J.
dc.contributor.author Schurr, Dennis Patrick en_US
dc.contributor.committeeMember Kim, Jin-Yeon
dc.contributor.committeeMember Sabra, Karim G.
dc.contributor.department Civil and Environmental Engineering en_US
dc.date.accessioned 2011-03-04T20:59:54Z
dc.date.available 2011-03-04T20:59:54Z
dc.date.issued 2010-08-30 en_US
dc.description.abstract The prevalence of concrete and cement-based materials in the civil infrastructure plus the risk of failure makes structural health monitoring an important issue in the understanding of the complete life cycle of civil structures. Correspondingly, the field of nondestructive evaluation (NDE) has been maturing and now concentrates on the detection of flaws and defects, as well as material damage in early stages of degradation. This defect detection is typically usually done by looking at the impulse response of the medium in question such as a cement-based material. The impulse response of a solid can be used to image a complex medium. Classically, the waveform is obtained by an active setup: an ultrasonic signal is generated at one location and recorded at another location. The waveform obtained from imaging can be used to quantitatively characterize the medium, for example by calculating the material's diffusivity coefficient or dissipation rate. In recent years, a different monitoring technique has been developed in seismology to measure the velocity of different kinds of waves, the Coda Wave Interferometry (CWI). In this CWI technique, the main focus is given to the late part of the recorded waveform, the coda. CWI is now successfully used in seismology and acoustics. In the current research, CWI is applied on concrete in different damage states to develop basic knowledge of the behavior of the wave velocity, and how it can be used to characterize cement-based materials. By comparing two impulse responses, the relative velocity change between the two impulse responses is used to characterize damage. Because of the stress-dependency of the velocity change, the calculations can also be used to directly calculate the Murnaghan's and Lam´e's coefficients. The newer technique of CWI is applied - the Stretching Technique (ST) [27]. The first goal of this research is to establish the viability of using CWI in cement-based materials. Next, we use the ST in the application of stress as we compress concrete samples for the detection of thermal damage, ASR-damage and mechanical softening. en_US
dc.description.degree M.S. en_US
dc.identifier.uri http://hdl.handle.net/1853/37237
dc.publisher Georgia Institute of Technology en_US
dc.subject Diffuse field en_US
dc.subject Concrete en_US
dc.subject Coda wave interferometry en_US
dc.subject.lcsh Concrete Defects
dc.title Monitoring damage in concrete using diffuse ultrasonic coda wave interferometry en_US
dc.type Text
dc.type.genre Thesis
dspace.entity.type Publication
local.contributor.advisor Jacobs, Laurence J.
local.contributor.corporatename School of Civil and Environmental Engineering
local.contributor.corporatename College of Engineering
relation.isAdvisorOfPublication 5af40958-ece2-4a76-b071-5ba4c6d99d80
relation.isOrgUnitOfPublication 88639fad-d3ae-4867-9e7a-7c9e6d2ecc7c
relation.isOrgUnitOfPublication 7c022d60-21d5-497c-b552-95e489a06569
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