Characterization of distributed damage in concrete using advanced impact-echo method

R. A. Livingston, A. M. Sutin, N. McMorris, M. Ceary, A. M. Amde

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

The extent of damage caused by delayed ettringite formation has not yet been established. A field study of damaged bridges has been initiated in the state of Maryland involving both destructive and nondestructive test methods. To characterize the physical damage in the form of distributed microcracking, a modified version of the impact echo test was used. This used the attenuation of the echoes as the parameter to quantify the damage rather than the pulse velocity. The successive peaks in the waveforms were fitted to an exponential decay model and Q factor was calculated. The Q factor was then used as the damage variable. Surveys were carried out on 12 concrete bridges across the state of Maryland. On apparently undamaged concrete, it was possible to obtain reasonably good fits to the data. The Q factor was typically higher than 15 which is consistent with negligible microcracking. However, waveforms taken on damaged concrete often were too distorted to permit a good fit using a simple high pass filtering method. Preliminary work using more advanced signal processing methods suggests that it is possible to extract the parameters even in damaged areas by using data windowing to eliminate the early transients, band pass filtering around the resonant frequency and using both positive and negative peak amplitudes. The preliminary measurements show decreasing of Q factor due to crack presence.

Original languageEnglish
Title of host publication11th International Conference on Fracture 2005, ICF11
Pages2304-2309
Number of pages6
StatePublished - 2005
Event11th International Conference on Fracture 2005, ICF11 - Turin, Italy
Duration: 20 Mar 200525 Mar 2005

Publication series

Name11th International Conference on Fracture 2005, ICF11
Volume3

Conference

Conference11th International Conference on Fracture 2005, ICF11
Country/TerritoryItaly
CityTurin
Period20/03/0525/03/05

Fingerprint

Dive into the research topics of 'Characterization of distributed damage in concrete using advanced impact-echo method'. Together they form a unique fingerprint.

Cite this