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L
OCATING
REINFORCEMENT
BARS
R
can see. A block of wood or plastic 20 mm to 45 mm thick can be held between the search head
and the bars to simulate the depth of concrete cover.
Start from the simplest situation, a single straight bar, and progress through parallel bars, lapped
bars, and crossing bars. As you develop skill and confidence with uncovered bars, move on to
locating bars in more realistic situations.
5.6 Surface mapping
When you are locating layers of reinforcement bars it is good practice to ‘map’ the concrete surface
in a systematic manner. The following steps describe a mapping technique which can be used to
locate two layers of reinforcement bars at right angles to each other.
1. Hold search head horizontally.
Scan up and down to locate (predominantly) horizontal bars.
2. Hold search head vertically.
Scan from side to side between horizontal bars to locate vertical bars.
Note:
In some situations, it will be more appropriate to scan first for the vertical bars and then the
horizontal bars.
331.book Page 21 Thursday, March 12, 2009 9:46 PM
