Abstract
The purpose of the research was to study the corrosion
rate of steel reinforcement by the linear polarization
technique and to compare the results with direct
observations of corrosion rate. Other electrochemical
measurements such as corrosion potential and concrete
resistivity were also studied.
Six reinforced concrete test slabs were prepared in the
laboratory. Corrosion of the reinforcement was initiated
by adding chloride to the concrete mix. The slabs were
stored in conditioned climate rooms. The rate of
corrosion, corrosion potential and concrete resistivity
were monitored by periodical measurements of the slabs
over 420 days. The scatter of the measurement results was
studied.
To determine the real rate of corrosion some of the
concrete slabs were broken after the measurement period.
The steel reinforcement was exposed and the amount of
corrosion was evaluated both visually and by the
gravimetric method. The observed amount of corrosion was
compared with the theoretical amount of corrosion
calculated on the basis of corrosion rate measurements.
The depths of corrosion determined by the gravimetric
method and the electrochemical method correlate well with
each other but the depth of corrosion based on the
gravimetric method was on an average six times greater
than that based on corrosion rate measurements. The
reason for this is not fully known to the author. It
seems that of all the measurement results, those that
indicate the maximum values of corrosion rate are nearest
to the correct level and some of the measurement results
show too low a rate of corrosion. Thus a single
measurement may not be adequate to obtain a reliable
value of corrosion rate.
Original language | English |
---|---|
Place of Publication | Espoo |
Publisher | VTT Technical Research Centre of Finland |
Number of pages | 13 |
Publication status | Published - 1999 |
MoE publication type | D4 Published development or research report or study |