Chloride :
Year of Corrosion Initiation Assessment
The
chloride analysis tool, DTI
DME 5.1 developed by John
Broomfield et al is a spreadsheet which takes as its inputs chloride
content and cover measurements and predicts Chloride Rates using
the equation below:
(Cmax -
Cd)/(Cmax - Cmin) = erf( x /
2(Dct)0.5)-----------
Ficks
second
law of Diffusion
C(x,t)/C(s) =
ERFC( x / 2(Dct)0.5)
Where
Cmax is
the surface concerntration
Cmin is
the background concerntration
erf
is the error function
x is
depth
Dc is
diffusion constant
t is
time
Note
In cases where
chlorides data are not readily available then the "Time to Corrosion
Initiation" value has to be estimated. This is a key parameter
that is required within the recommendation tool. Recommendation of
the appropriate repair strategy is the next
logical step after the analysis.