Title:
Detecting Flaws in Concrete Beams and Columns Using the Impact-Echo Method
Author(s):
Y. Lin and M. Sansolone
Publication:
Materials Journal
Volume:
89
Issue:
4
Appears on pages(s):
394-405
Keywords:
beams (supports); columns (supports); nondestructive tests; impact; Materials Research
DOI:
10.14359/2579
Date:
7/1/1992
Abstract:
The studies summarized in this paper demonstrate the feasibility of using the impact-echo method for detecting flaws in reinforced concrete beams and columns. Numerical studies were performed to gain an understanding of the impact-echo response of square, rectangular, and circular columns, and rectangular beams containing voids, cracks, and honeycombing. Experimental studies were carried out on full-size plain and reinforced concrete beam and column segments containing flaws at known locations. Results obtained from these studies show that the transient impact response of a solid beam or column is composed of a number of resonant frequencies caused by cross-sectional modes of vibration. These modes depend on the geometry and dimensions of a beam or column's cross section. It is also shown that the presence of a defect disrupts the frequency pattern produced by the cross-sectional modes. This makes the response obtained from a beam or column containing a flaw easy to identify. In most cases, the location of the defect is also easy to determine. Suggested procedures for field evaluation of beams and columns are given.