Accelerated carbonation testing of alkali-activated binders significantly underestimates service lif
By S. A. Bernal, J. Provis, D. Brice, Adam R. Kilcullen, P. Duxson, J. V. van Deventer. 2012
339 citations recorded by the source corpus.
The carbonation resistance of alkali-activated binders is often tested via accelerated test protocols designed for Portland cements, without questioning whether the tests replicate the mechanisms observed in service. Thus, validation of accelerated methods is required to enable realistic prediction of material performance. Changes in pore solution equilibria cause the formation of sodium bicarbonates during accelerated carbonation, compared with hydrous sodium carbonates in natural carbonation. This shifts the carbonation mechanism to favour more rapid reaction progress, to give a higher apparent degree of acceleration (compared to natural conditions) than in Portland cements. The pore solution pH under accelerated carbonation is significantly lower than at natural CO2 concentrations, leading to a falsely short predicted service life (time to expected corrosion of embedded steel), as natural CO2 concentrations appear not to reduce the pH below 10. Thus, accelerated carbonation testing is unduly aggressive towards alkali-activated binders, and test results must be cautiously interpreted.
Subfields: Civil and Structural Engineering, Materials Chemistry
View Paper: https://www.semanticscholar.org/paper/940c73b542854d6b5637f4256314afce2e86bb77
How researchers see this paper
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In Civil and Structural Engineering
- J. Provis
- Zuhua Zhang
- S. A. Bernal
- J. V. van Deventer
- Rackel San Nicolas
- A. Wang
- Daosheng Sun
- Kaiwei Liu
In Materials Chemistry
- J. Provis
- Zuhua Zhang
- S. A. Bernal
- J. V. van Deventer
- Rackel San Nicolas
- A. Leemann
- A. Wang
- Kaiwei Liu
Citations in the corpus
- The Durability of Alkali-Activated Materials in Comparison with Ordinary Portland Cements and Concretes: A Review (2020, methodology): “In the case of natural carbonation, the main carbonation product of AAS is Na2CO3 10H2O; under accelerated carbonation conditions, it is NaHCO3 [101].”
- Alkali-activated slag cements produced with a blended sodium carbonate/sodium silicate activator (2016, background): “…technical properties, such as high temperature resistance (Guerrieri et al., 2010) and resistance to sulfate (Ismail et al., 2013) and acid attack (Bernal et al., 2012a; Lloyd et al., 2012), meaning that they are suitable for use in various specialised applications, as well as for general-purpose…”