I
MPACT
E
CHO
(IE)
www.olsoninstruments.com
www.olsonengineering.com
corresponds to actual defect of 30% depth lost or 34% circumferential lost. The interpretation of the
Impact-Echo Scanner results, however, shows a downshift in frequencies from lengths of 3.48 – 6.1 m
(137 to 240 in), indicating minor to major voids at duct locations where no actual Styrofoam defect in
place. Radiography is required to confirm the actual location of Styrofoam voids.
Figure 6 – IE Results from the South Wall with Actual Design Defects of Second Duct
Figure 7 – IE Results from the South Wall with Actual Design Defects of Third Duct
240
East End
16%, 6%
0
60
120
180
20
40
80
100
140
160
200
220
Length of Wall (inches)
0
4.8
4
3.2
2.4
1.6
0.8
Wall Height (ft)
West End
36”
240
204
132
24%, 13%
16%, 6%
76%, 87%
Grout defect appears at
length of 135 inches – Defect Size 24%,
13%
Worst defect area
Minor grout defect where
there is no Styrofoam
Grout defect appear at
Lengths of 6 – 30”
0
60
120
180
240
20
40
80
100
140
160
200
220
0
4.8
4
3.2
2.4
1.6
0.8
Wall Height (ft)
29”
65”
101”
137”
16%, 6%2”
76%, 87%
16%, 6%
40%, 34%
32%, 23%
Length of Wall (inches)
West End
East End
Grout defect appears
from lengths of 84 - 126 inches
