Handbook for Bridge Inspections - TSP2

Figure 7.3-17 E.wmpleQJRlIsl Level £
Cutting open the concrete reveals the actual level of corrosion to
the reinforcement and acts as a check for the resu lts of other materials
testing. The method is destructive and ought only to be
employed to a very limited ex tent. It shoul d be noted that the area
to be cut open is not necessarily representative of an entire bridge.
Acceptance Inspections & Major Inspections
Cutting open concrete fo r corrosion assessment purposes is not
usually undertaken. However, it can be worthwhi le in the assessment
of any cross-secti onal reduction in the reinforcement when
there is visible evidence of corrosion.
Special Inspections
tain ing latent corrosion. In these cases areas with cl ear evidence of
corrosion should not be cut open.
Should noth ing else specifica lly be mentioned, then cutting operations
should be undertaken for consecutive areas measured for
potentiality for the following locations:
* The lowest measure of potentiality
* The middle measure of potentiality
* The highest measure of potentiality
When cutting into concrete to veri fy ECP measurements the fo llowing
materials tests should be undertaken in the order given:
I. ECP measurements (recording the potential and resistance
levels)
2. Measuring concrete cover
3. Measurin g the ch loride content from layers adj usted for the
cover measured such that the chloride level is measured in each
or the layers.
4. Cutting operati ons and evaluating the level o f rust and the
reduct ion in the cross-section.
5. Measuring the depth of ca rbonisation