I
MPACT
E
CHO
(IE)
www.olsoninstruments.com
www.olsonengineering.com
This section shows several example time domain and frequency domain records of sound concrete,
concrete with internal cracks and concrete with bad consolidation (internal honeycomb). As mentioned
previously in Section 1.2, data analysis of the IE test is performed in the frequency domain. Sound
concrete is determined by a sharp single dominant peak in the frequency data and the calculated depth
(from the peak) should match the expected thickness of the tested structure. The pictures below show the
IE test data from a 15” thick transfer wall. The first spectrum shows sound concrete. The second
spectrum shows concrete with internal honeycombing and the third picture shows concrete with internal
cracks
Typical internal honeycomb or voids can be indicated by a downshift in the frequency peak resulting in
an increase in the apparent thickness. In addition, possible multiple peaks can also present in the
spectrum of concrete with internal honeycombing. The picture below shows an example of concrete with
poor consolidation (with internal honeycomb).
4.6
Example IE Data
Calculated Thickness = 14.45”
Calculated Thickness = 14.45”
Calculated Thickness = 16.38” – 13% increase in the
apparent thickness
Calculated Thickness = 16.38” – 13% increase in the
apparent thickness
