Thermodynamic modelling of the carbonation process of alkali-activated slag cements

Author(s): Xinyuan Ke, Susan Bernal, John Provis
Paper category: Proceedings
Book title: Proceedings of the International Conference on Sustainable Materials Systems and Structures (SMSS2019) Durability, Monitoring and Repair of Structures
Editor(s): Ana Baričević, Marija Jelčić Rukavina, Domagoj Damjanović, Maurizio Guadagnini
ISBN: 978-2-35158-217-6
e-ISBN: 978-2-35158-218-3
Publisher: RILEM Publications SARL
Publication year: 2019
Pages: 325-332
Total Pages: 813
Language: English

Abstract: The carbonation of cementitious materials induced by their interaction with atmospheric CO2, is one of the main degradation mechanisms threatening their durability. Despite the extensive experimental work that has been carried out attempting to determine carbonation resistance of alkali-activated cements, it remains to some degree unknown what factors influence carbonation of these materials, and how carbonation resistance under service conditions can be estimated. Hence, there is an urgent need to develop modelling tools that can be used to predict the potential carbonation behaviour of these materials, based on the bulk binder composition. In this study, a thermodynamic model to predict the phase evolution of alkali-activated slags exposed to an accelerated carbonation environment (1% v/v CO2) is proposed. This model predicts semi-quantitatively the phase assemblages, as a function of CO2 exposure, considering the bulk chemistry of the slag and activators used for producing the cementitious binders. Experimental data retrieved from the literature were used to support the development of the proposed model. The challenges identified during the development of this model are also discussed, including recommendations for its future modification.

Online publication :2019
Publication type : full_text
Public price (Euros) : 00