A COMBINED KINETIC AND THERMODYNAMIC APPROACH FOR MODELLING THE PORE SOLUTION OF PC-FLY ASH CEMENTS

Author(s): N. Eroukhmanoff and A. Al-Tabbaa
Book Title: RILEM International Symposium on Concrete Modelling - CONMOD 2014
Editor: Kefei Li, Peiyu Yan and Rongwei Yang
ISBN: 978-2-35158-139-1
e-ISBN: 978-2-35158-140-7
Publisher: RILEM Publications SARL
Publication year: 2015
Pages: 9-17
Total Pages: 9
Language: English

Abstract: Thermodynamic and kinetic modelling is currently an important tool in cement chemistry which enables to predict the evolution of the solid and liquid phases of a given cementitious system. To date, it has been able to predict several characteristics of Portland cement-Fly Ash (PC-FA) blended cements: the composition of hydrates assemblage, the kinetic reactivity of fly ash particles, and more recently the state of alkali ions in the pore solution. However, some of these models cannot yet predict the experimental observations made on the overall pore solution characteristics of PC-FA blended cements. In this study, we used the geochemical speciation code (GEMS-PSI) to investigate the unmodelled observations in terms of the properties of the pore solution of PC blended with a low calcium fly ash. We used recent kinetic modelling data describing experimentally observed behaviour of the dissolution of the major and minor phases present initially in PC-FA cementitious systems as input data in GEMS-PSI to predict the pore solution chemistry development of PC-FA blended cements and how it was correlated to the structural differences between PC and PCFA blends. The results obtained with this model were compared with the latest relevant experimental data found in the literature on PC-FA blended cements.

Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00