Page 83 - Riem-Vol6_nº2

254 IBRACON Structures and Materials Journal • 2013 • vol. 6 • nº 2
Ultrasonic tomography in concrete
the grid spacing, and the travels time for each specimen were in-
troduced in TUCon. TUCon, then, processed and exhibited the
numerical results. These results were exported and inserted into
another third-party program to generate, by linear interpolation, the
tomograms shown, in Figure 14 to 17, representing sections at
mid-height of specimens CP1, CP2, CP3 and CP4, respectively.
4.4 Analysis of results
The tomogram of CP1 specimen (Figure 14) showed good recon-
struction of the analyzed section. It is clear that the 5 cm EPS
block is at the center of the section with its correct size. In tomo-
Figure 14 – CP1 Tomogram – (a) specimen and location of analised section
(b) tomogram – (c) legend in m/s
A B C
Figure 15 – CP2 Tomogram– (a) specimen and location of analised section
(b) tomogram – (c) legend in m/s
A B C
gram of Figure 14, as well as in the others produced, there is some
variation on the ultrasonic velocity in regions without internal flaws,
represented by the colors yellow to red. This variation does not in-
validate the results, since it should be considered that in an actual
experiment, the material is not homogeneous and thus the read-
ings can bring small inaccuracies. These variations would tend to
decrease if smaller grid spacings were used.
The tomogram of CP2 specimem (Figure 15) presents a similar
shape to Figure 14 but with lower ultrasound velocities, represent-
ed by the violet regions. Since the only difference between CP1
and CP2 is the height of the EPS block inserted into the specimens
(5 cm to 10 cm for CP1 and CP2, respectively), it can be assumed