Carbo Detect™ is a simple, dye-based field test designed for the rapid detection and assessment of carbonation in concrete.
Features & Benefits
- Fully on-site testing capability
- Provides clear indication of carbonation depth
- Minimal operator training required; no specialised equipment needed
- Uses a single, environmentally safe indicator dye
- Results available in under five minutes
- Cost-effective, fast and easy to apply
- Simple visual interpretation of results
Overview
Carbo Detect™ is a straightforward colourimetric test used to identify carbonation in concrete. The single reagent is sprayed directly onto a freshly exposed concrete surface.
The indicator reacts with the concrete’s pH level:
- Pink colouration indicates uncarbonated (alkaline) concrete
- No colour change (remains colourless) indicates carbonated concrete (lower pH)
This provides a rapid and reliable visual method for assessing carbonation depth in the field.
Technical Background
Carbonation is one of the primary causes of reinforcement corrosion in concrete, alongside chloride ingress. It occurs when carbon dioxide from the atmosphere reacts with alkaline compounds in the concrete, reducing its pH.
As carbonation progresses, the pH drops to levels at which embedded steel reinforcement is no longer protected and corrosion can begin.
Carbon dioxide dissolves in moisture within the concrete to form carbonic acid, which can penetrate through porous or low-quality concrete. The rate and depth of carbonation are influenced by factors such as:
- Low cement content
- High water–cement ratio
- Poor curing practices
- Open or porous concrete structure
- Reduced concrete cover to reinforcement
Carbonation is most commonly observed in older structures, particularly buildings and exposed concrete elements.
Method of Use
Carbo Detect™ acts as a pH indicator applied to a freshly exposed concrete surface. The reagent is simply sprayed onto the test area.
- In uncarbonated concrete, the surface turns pink
- In carbonated concrete, no colour change occurs
For dry concrete surfaces, lightly misting the area with water prior to testing can improve visibility of the colour response.
To determine carbonation depth, the reagent can be applied along a drilled core from the surface down to the reinforcement. This clearly shows the extent of carbonation and helps assess the likelihood of corrosion, which occurs once carbonation reaches the steel reinforcement.
Care should be taken to ensure drilling dust or debris does not contaminate the test surface.
Kit Contents – CB-6000 Test Kit
- 200 ml reagent (sufficient for approximately 100 tests)
- Spray applicator
- Protective carrying case