The effect of chemical attack on the three dimensional porosity of alkali activated systems

Author(s): L.E. Gordon, R.J. Myers, Lu. Cao, J.L. Provis and J.S.J. van Deventer
Paper category: conference
Book title: Microstructural-related Durability of Cementitious Composites
Editor(s): Guang Ye, K. van Breugel, Wei Sun and Changwen Miao
Print ISBN: 978-2-35158-129-2
e-ISBN: 978-2-35158-123-0
Publisher: RILEM Publications SARL
Publication year: 2012
Pages: 283 - 291
Total Pages: 9
Language: English

Abstract: Alkali activated materials (‘geopolymers’) were exposed to the solvents used in post combustion carbon capture to assess their durability and potential use as a construction material for replacing costly stainless steel. The development of an understanding of the durability performance of alkali-activated materials relies on the ability to understand the geometry, tortuosity and connectivity of the pore networks within the aluminosilicate gel binders, as porosity and the resulting permeability is believed to be the key to durability on exposure to aggressive agents. The analysis of the gel structures in three dimensions can be made possible by the use of synchrotron radiation-based X-ray tomography instrumentation. Information can be extracted from the raw data by forming a tomographic reconstruction, from which greyscale histograms allow the segmentation into ‘pore’ and ‘gel’ regions. The use of random walker algorithms then determines the geometrical parameters of the pore network. This study examines the use and limitations of this technique for obtaining porosity information in alkali activated materials formed using fly ash and metakaolin, each with the addition of granulated blast furnace slag, and also a traditional blast furnace slag based composite cement system, following exposure to the solvents, ethanolamine and potassium carbonate.

Online publication: 2012-05-16
Publication Type: full_text
Public price (Euros): 0.00