Handbook for Bridge Inspections - TSP2

For roads subject to salti ng spot checks of the chloride content
should be taken in exposed areas such as pi llars supporting the
approach sections to a bridge and the edge girders of bridges along
the route. This is most va lid for bridges constructed according to
older regulations, namely before 1996/97.
Repeated chloride content measurements ought to be taken during
each main inspection at approximately the same locations as a fol ­
low-up over time. Measures can accordingly be taken timeously
should the need arise.
For new large coastal bridges inspection routines should be fo llowed
or establi shed if necessary.
Spot tests should be carried out on older bridges which have not
previously been chec ked for chloride incursion. The need for a
special inspection incorporating more extensive materials tests
should be assessed.
Measurements of the covering and the depth of any carbonisation
should be undertaken at the sa me time as any dri lling for dust in
connection with chloride tests. Alternatively a special inspection
can be carri ed out including comprehensive materials testing and,
if necessary, EC P measurements.
Special Inspections
Chloride measurements are carri ed out according to special prescriptions.
Their extent and location should be taken into during
execution of the test.
Ad vantages and
Disadvantages
On site testing is cheap and easy to carry Oul but are less accurate
than laboratory methods. Analyses conducted in a laboratory are
time-consuming and costly but result in a high level of accurac
7.3.4 Corrosion Testing (ECP)
To measure the reinforcement's electrochemical potential (ECP)
and associated resistance in order to assess the probability of the
reinforcement co rroding.
Procedures
Reference is made to the National Publ ic Roads Administration
Handbook No. 0 15: "On Site Testing", Method NO. 15.552 and the
National Pub lic Roads Administration, Bridge Division's Report
No. 94- 16 Bridges:
"Recommendations for the Equipment for Measuring
Electrochemical Potential (ECP)".
General
Scope
ECP measurements should be taken if latent rein forcement corrosion
is suspected.