On a possibility of structure identification by microindentation and acoustic emission

Title: On a possibility of structure identification by microindentation and acoustic emission
Author(s): Janusz Kasperkiewicz
Paper category : conference
Book title: NICOM 2: 2nd International Symposium on Nanotechnology in Construction
Editor(s): Y. de Miguel, A. Porro and P.J.M. Bartos
Print-ISBN: 2-912143-87-X
e-ISBN: 2912143888
Publisher: RILEM Publications SARL
Publication year: 2006
Pages: 151 - 159
Total Pages: 9
Nb references: 11
Language: English

Abstract: It is possible to apply microindentation to evaluate certain mechanical properties of strongly inhomogeneous materials like concrete, cement mortar, cement paste, etc. At the microscale there is, however, a problem of precise identification of the phase of the composite where the indenter is actually located. A pilot study was dedicated to supporting the indentation test by an accompanying Acoustic Emission signal, (AE). So far the AE approach was little used in connection with the micro-indentation experiments on concrete materials, because interpretation of such signal is difficult, due to its very low energy, uncertainty of the position of the indenter, and due to problems with discrimination, (separation), of signals of different origin.
To get information on composition of the tested material the AE signals were processed by wavelets analysis and to the resulting data applied were procedures of Machine Learning, (ML; a soft computing approach). The information was extracted from the database of impulses collected at three levels of frequency. A rule concerning distribution of impulses was discovered by an ML program, (AQ19). The rule made possible identification in the hardened material of the presence of silica fume - one of additives used in modern concrete composites.

Online publication: 2005-11-17
Publication type : full_text
Public price (Euros): 0.00