Characterising the structure and permeability of alkali-activated binders

Title: Characterising the structure and permeability of alkali-activated binders
Author(s): John L. Provis, Idawati Ismail, Rupert J. Myers, Volker Rose, Jannie S.J. van Deventer
Paper category : conference
Book title: International RILEM Conference on Advances in Construction Materials Through Science and Engineering
Editor(s): Christopher Leung and K.T. WAN
ISBN: 978-2-35158-116-2
e-ISBN: 978-2-35158-117-9
Publisher: RILEM Publications SARL
Publication year: 2011
Pages: 493 - 501
Total Pages: 9
Nb references: 36
Language: English

Abstract: In the development of new low-CO2 binders for use in concretes, the ability to predict, control and prove durability is paramount in importance. Alkali activation of aluminosilicate materials, particularly fly ash and ground granulated blast furnace slag, leads to the formation of binders with excellent mechanical properties, and advances in technology and know-how have now led to the ability to produce workable and versatile concretes using these binders. However, as a relatively new material, the durability in-service of alkali-activated binders remains unproven, and so analytical techniques must be developed to predict the likely service life of structures made from alkali-activated concretes. There are a host of standard durability tests which are widely applied to Portland cement concretes, but the applicability of many of these tests to alkali-activated binders remains to be determined. Here, we present the results of some of this benchmarking process, applying standard test procedures to alkali-activated and Portland-cement based samples and comparing the data obtained.
To provide an understanding of how the test results relate to microstructure and nanostructure, we also present the results of tomographic analysis of the alkali-activated binders on two different length scales: microtomography and nanotomography, both implemented using hard X-ray synchrotron radiation. These techniques provide the possibility to develop a fundamental understanding of the three-dimensional arrangement of pores and binder material within a suite of alkali-activated samples over a range of length scales from tens of nanometers to tens of microns, including the calculation of pore network tortuosity parameters. This information is able to be used directly in comparison with the results of laboratory testing to provide a fundamentally-based discussion and analysis of the durability of alkali-activated binders.

Online publication: 2011-10-31
Publication type : full_text
Public price (Euros): 0.00