A service life based global warming potential for high-volume fly ash concrete exposed to carbonation

• HVFA concrete is less resistant to carbonation than OPC concrete but still is durable.
• Colorimetric assessment underestimates the actual (microscopic) carbonation depth.
• Service life of HVFA concrete estimated with a simplified model exceeds 100 years.
• When curing and weather effects are considered, service life also exceeds 100 years.
• The GWP of carbonation exposed HVFA concrete is 18–27% lower than OPC concrete’s GWP.

To evaluate the global warming potential (GWP) of carbonation exposed high-volume fly ash (HVFA) concrete, its expected service life should be known. In the early stages of product development, this is done with rudimentary prediction models based on simple colorimetric carbonation testing. More sophisticated methods (e.g. thin section analysis) and prediction models that consider concrete curing and meteorological conditions (cf. Fib Bulletin 34) can be used later on if the former predictions look promising. This paper shows that both rudimentary and advanced prediction models result in significant GWP decrease (−18% to 27%) for HVFA concrete, regardless the underlying carbonation assessment method.