Exploring natural and accelerated carbonation of alkali-activated slag
Joonho Seo, Seunghee Park, Seunghee Park, G.M. Kim, Solmoi Park, Solmoi Park
Abstract
The present study explores the natural and accelerated carbonation of alkali-activated slag. Six different activators of NaOH, Na 2 SiO 3 , Na 2 CO 3 , Na 2 SO 4 , CaO or MgO were used to make alkali-activated slag samples, and samples were accelerated-carbonated for 28 days or naturally-carbonated for 2 years. The types of calcium carbonate formed after carbonation varied depending on the activator and the carbonation condition. The stability of hydrotalcite-like layered double hydroxide was found to be underestimated when exposed to accelerated carbonation conditions, thus requiring caution when testing the durability performance of these materials under such conditions. CaCO 3 and the highly crosslinked aluminosilicate gel were the predominant carbonation products in both accelerated and natural carbonation, with the effects on the Al local environment differing between the carbonation conditions.