Carbonation in the pore solution of metakaolin-based geopolymer

An experimental approach based on the study of the pore solution of metakaolin-based geopolymer has been established in this study to investigate the phenomenon of carbonation in these materials. The results obtained showed a very fast decrease in the pH, compared to Portland cement, and an almost total carbonation of the pore solution in natural condition after only 14 days. In natural CO₂ conditions, the formation of sodium carbonate did not lead to a decrease of pH below 10.5 at one year, thus limiting the risk of corrosion by depassivation of the reinforcement. Accelerated carbonation performed under 50% of CO₂ highlighted the formation of large amounts of sodium bicarbonate responsible for a lower pH of the pore solution, and a potential risk of corrosion by carbonation. That result also demonstrated that the accelerated carbonation tests made for Portland cement are not representative of the natural reaction in geopolymer cases.

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 01609853
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 15 2016 2:47PM