Cormap - Identifying Rebar Corrosion
A Simple Economical Method for Identifying Areas of Probable Rebar Corrosion
Features & Benefits
- Easy to use
- Detachable electrode extension pieces facilities measurements in hard to reach locations.
- High impedance digital meter is designed for tough field conditions
- Economical
- Conforms to ASTM C876-94
Technical Specifications
Corrosion, which is an electrochemical process, occurs in concrete when oxygen and moisture are present. The actual corrosion is an exchange of energy within different sections of the uncoated reinforcing steel. The relative energy levels can be determined in relation to a reference electrode with a stable electrochemical potential.
By connecting a high impedance voltmeter between the reinforcing steel and a reference electrode placed on the concrete surface, a measurement can be made for the half cell potential at the location of the reference cell. This then is a measurement of the vicinity of the reference cell.
The reference cell is copper in copper sulphate solution.
By taking half cell potential measurements a fixed distance apart a grid of half cell potentials can be quickly made and thus areas delineated with a high probability of corrosion of the reinforcing steel.
To analyze the results, the measurements made with CorMap can be plotted on a grid and lines of possible corrosion activity.
For example the following guide is listed in ATM C876 using a Copper/Copper sulphate half cell:
- For readings of -350 mV and greater there is a 95% chance of active steel corrosion.
- For readings-200 to -350 mV there is a 50% chance of active steel corrosion.
- For reading less than -200 mV there is only 5% chance of active steel corrosion.
The Method is particularly useful for:
- Bridge Decks
- Parking Garages
- Concrete Piers & Docks
- Substructure
- Tunnel Lining
- Foundations
| CorMap System CM-4000 | |
|---|---|
| One CM-4500 |
High impedance voltmeter |
| Two CM-4410 |
Electrode extension pieces - each 18 inches (41 cm) log |
| One CM-4400 |
Reference electrode including copper sulphate reservoir |
| One CM-4210 |
Container of copper sulphate (capacity 8 oz. 250 ml.) |
| One CM-4220 |
Wetting agent reservoir (capacity 4 oz. 125 ml.) |
| One CM-4420 |
Dispensing sponge |
| One CM-4300 |
Cable reel with 250 ft (80 meters) cable |
| One CM-4100 |
Carrying case 16"x11"x4" (152x28x10 cm) |
| Total weight 15 lbs(7 Kgs) | |
For further information or to place an order for the Cormap - Identifying Rebar Corrosion CLICK HERE, call us Toll-Free at: 1.877.884.TEST, or click on the "HOW TO ORDER" Button