ENGINEERING – TRUCTURAL ENGINEERING — CONCRETE CALCULATOR
Concrete Carbonation Depth
A precise tool.
What is the Concrete Carbonation Depth & How does it work?
Carbonation is a natural process where carbon dioxide from the atmosphere reacts with calcium hydroxide in hardened concrete, forming calcium carbonate. This reaction reduces the alkalinity of the concrete, potentially compromising the protective passive layer around embedded steel reinforcement.
The rate at which carbonation progresses is commonly expressed by a simple diffusion‑controlled model: the carbonation depth grows proportionally to the square‑root of exposure time. The proportionality constant, known as the carbonation coefficient, captures material properties, environmental CO₂ concentration, and relative humidity.
Engineers use this model to predict when the carbonation front will reach the reinforcement, allowing them to specify adequate concrete cover or to plan maintenance interventions. By comparing the calculated depth with the actual cover thickness, the risk of corrosion initiation can be assessed.
x = k sqrt{t}
x = carbonation depth (mm)
k = carbonation coefficient (mm/√year)
t = exposure time (years)
k = carbonation coefficient (mm/√year)
t = exposure time (years)
Parameters
Result
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Frequently Asked Questions
What is the formula for calculating concrete carbonation depth?
The carbonation depth grows proportionally to the square root of exposure time.
How does carbonation affect concrete?
Carbonation reduces the alkalinity of concrete, potentially compromising the protective layer around embedded steel reinforcement.
What is the rate of carbonation in concrete?
The rate of carbonation progresses according to a diffusion-controlled model where depth increases with the square root of time.
Why is it important to monitor carbonation in concrete?
Monitoring carbonation helps assess the durability and service life of concrete structures, especially those with embedded steel reinforcement.
Can you explain the diffusion-controlled model for carbonation depth?
The diffusion-controlled model states that the carbonation depth increases proportionally to the square root of the exposure time to carbon dioxide.
Results are for informational purposes only and do not constitute professional advice.