Service Life Estimator
Will your concrete cover last 50 years against carbonation? Pick your mix, cover depth and location — see the probability of corrosion initiation instantly. Each calculation automatically compares your cement against a lower-carbon alternative, showing the trade-off between durability and sustainability.
Location
Select a city to determine the mean annual relative humidity for your location.
Mix Design
Nominal Concrete Cover
What is XC3?
Moderate humidity, sheltered from rain. Carbonation is the dominant degradation mechanism. CO₂ from the atmosphere lowers the concrete pH until the protective oxide layer on the reinforcement is destroyed, initiating corrosion.
Key Factors
- Cover depth — the physical barrier protecting the steel.
- w/c ratio — lower ratio = denser concrete = slower carbonation.
- Cement type — high-slag cements carbonate faster due to lower Ca(OH)₂ reserves.
- Humidity — carbonation is fastest at 50-70% RH.
Durability vs. Sustainability
Lower-carbon cements reduce embodied CO₂ but often carbonate faster due to reduced Ca(OH)₂ reserves — potentially shortening the service life of the cover zone. A concrete that appears sustainable on a per-tonne basis may actually deliver more carbon per year of useful life if it requires earlier repair or replacement.
This tool lets you visualise that trade-off: every calculation automatically compares your chosen cement against a lower-carbon alternative, showing both the corrosion probability curve and the carbon intensity per year of service — so you can make an informed decision rather than relying on embodied carbon alone.
BS 8500-1:2023 now uses strength as the primary durability criterion for XC exposure, accommodating low-carbon binders. However, the long-term carbonation performance of newer binder systems still warrants independent validation — particularly for high-replacement cements. Our specialists can help verify that your low-carbon mix meets the required service life.
Speak to a specialistDisclaimer: This tool provides indicative estimates for preliminary assessment purposes only based on the fib Model Code 34 methodology. Results should not be relied upon for detailed design or construction decisions. Durable Designs accepts no liability for any loss arising from the use of this tool. For project-specific durability verification, independent specialist analysis is essential.