This document describes a patented field system called Gecor 6 for measuring the corrosion rate of reinforcement bars in concrete structures. The system uses half-cell potential testing and measures the potential and electrical resistance between the reinforcement and concrete surface. It stores measurements of corrosion rate, potential, polarization resistance, temperature, humidity and other data. The document provides details on the components, operation, and interpretation of results for evaluating corrosion activity and estimating repair costs and structure service life.

1. -M.ARIEF RAZACK
2017233001

2.  Non Destructive Testing is generally defined
as not impairing the intended performance of
the element or member under test and when
applied to concrete is taken to include
methods which cause localized surface zone
damage

3.  As a control check and an aid to the
monitoring of quality during manufacture
 During in-service inspection
 Critical defect assessment

4.  A unique patented field system for measuring
the rate of corrosion and other parameters of
reinforcement bars.
 It is based on the principle of half cell
potential test

5.  Corrosion Rate Analysis
 Structure Service Life Analysis
 Repair Cost Estimation

6.  The instrument measures the potential and
the electrical resistance between the
reinforcement and the surface to evaluate the
corrosion activity
 The electrical activity of the steel
reinforcement and the concrete leads them to
be considered as one half of weak battery cell
with the steel acting as one electrode and the
concrete as the electrolyte.

7.  The electrical potential of a point on the
surface of steel reinforcing bar can be
measured comparing its potential with that of
copper – copper sulphate reference electrode
on the surface.
 Practically this achieved by connecting a wire
from one terminal of a voltmeter to the
reinforcement and another wire to the copper
sulphate reference electrode.
 Then generally readings taken are at grid of
1 x 1 m for slabs, walls and at 0.5 m c/c for
Column, beams

8. Meter
 Dimensions-12 x 8 x 6.5 inches (30 x 20 x
16cm)
 Weight-9 Lbs. (4kg)
 Batteries-4 'D'•type alkaline (24 hours
operation)
 LCD Screen-2 line 16 character display
 Memory up to 100 corrosion rate readings

9. 
Dimensions-7'•diameter x .8'•(18 x 2cm)

Weight-2 Lbs. (0.9kg)
 Components
◦ 1 copper/copper sulphate central reference
electrode
2 copper/copper sulphate confinement sensor
electrodes
3 copper sulphate solution reservoirs
2 concentric stainless steel counter electrodes
1 sponge pad

10. The meter with 'A' sensor will measure and
store:
 Corrosion rate (Stern & Geary law).
 Corrosion potential
 Concrete Polarization Resistance
 Date, time and location of reading
https://youtu.be/lqmQ0Lq1RD8

11.  Dimensions-10.2•diameter x 1.4 (26 x
3.5cm)
 Weight-0.6 Lbs. (0.3kg)
 Components
◦ 1 copper/copper sulphate reference electrodes
1 copper sulphate solution reservoir
1 stainless steel counter electrode
1 solid state temperature probe 10°C to 80°C
1 Capacitance relative humidity probe 3 to 95%

12. The meter with "B"•sensor will measure and
store:
 Concrete resistivity
 Relative humidity
 Temperature (°C)

15. Corrosion rate values measured
by Gecor 6™ give precise information on the
risk of corrosion and the following broad
criteria have been established:
 Icorr <0.2µA/cm2 Passive condition
Icorr 0.2 to 0.5µA/cm2 Low corrosion
Icorr 0.5 to 1.0µA/cm2 Moderate corrosion
Icorr >1µA/cm2 High corrosion rate

16.  This method can be used to indicate the
corrosion activity associated with steel
embedded in concrete.
 This method can be applied to members
regardless of their size or the depth of
concrete cover.

17.  The test does not indicates actual corrosion
rate or whether corrosion activity has already
started, but it indicates the probability of the
corrosion activity depending upon the actual
surrounding condition.
 If the concrete surface has dried to the extent
that it is dielectric, then pre wetting of
concrete is essential.