Title: Application of Acoustic Emission and Laser Holography to Study Microfracture in Concrete

Author(s): A. K. Maji and S.P. Shah

Publication: Symposium Paper

Volume: 112

Issue:

Appears on pages(s): 83-110

Keywords: acoustic emission; concretes; lasers; microcracking; nondestructive tests; Structural Research

DOI: 10.14359/2846

Date: 1/1/1989

Abstract:
The fracture process of a composite material involves crushing or slippage of adjacent particles, microcracking, etc., resulting in changes in the load-versus-displacement behavior. A study of the fracture process is necessary to develop a rational material model. Laser holographic interferometry was applied to study the whole field deformation pattern. Speckle photography was used to measure quantitatively displacement discontinuities at bond cracks at various stages of loading. Acoustic emission (AE) techniques were applied to monitor microseismic activities resulting from the various fracture phenomena. The rate of microfracture was measured from the AE event rates. A source location algorithm was used to calculate the locations of the AE events. Specimens were made with different aggregate and void sizes to study their effect on crack patterns and load-displacement behaviors.