Abstract
Carbonation of cementitious materials induced by their interaction with atmospheric CO2 is one of the main degradation mechanisms threatening their durability. In this study, a novel thermodynamic model to predict the phase evolution of alkali-activated slags exposed to an accelerated carbonation environment is presented. This model predicts the phase assemblages of carbonated alkali-activated slag cements, as a function of CO2 uptake under 1 v/v % CO2 conditions, considering the bulk slag chemistry and activators used. The changes taking place during the carbonation process regarding the physicochemical properties of the main binding gel, an alkali calcium aluminosilicate hydrate (C-(N)-A-S-H), the secondary reaction products Ca[sbnd]Al and Mg[sbnd]Al layered double hydroxides, and amorphous aluminosilicate gels, were simulated and discussed. The predictions of the thermodynamic model are in good agreement with experimental data retrieved from the literature, demonstrating that this is a valuable tool for predicting long-term performance of alkali-activated slag cements.
Original language | English |
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Article number | 106158 |
Journal | Cement and Concrete Research |
Volume | 136 |
Early online date | 21 Jun 2020 |
DOIs | |
Publication status | Published - 1 Oct 2020 |
Funding
Participation of X. Ke in this study was sponsored by the Prize Fellowship at University of Bath . Participation of S.A. Bernal in this study was sponsored by EPSRC through ECF EP/ R001642 /1.
Keywords
- (A) Reaction
- (B) Thermodynamic calculations
- (C) Carbonation
- (D) Alkali-activated cement
ASJC Scopus subject areas
- Building and Construction
- General Materials Science