Reactivity of alkali-activated binders for stabilization/solidification of tunnel bor- ing muds

Author(s): Thomas Wattez, Martin Cyr, Cédric Patapy, Julien Waligora, François Olard, Laurent Frouin and Nicolas Musikas
Paper category: Proceedings
Book title: Proceedings of the International Conference on Sustainable Materials, Systems and Structures (SMSS2019) New Generation of Construction Materials
Editor(s): Marijana Serdar, Nina Štirmer, John Provis
ISBN: 978-2-35158-217-6,
Vol 1. ISBN: 978-2-35158-223-7
e-ISBN: 978-2-35158-218-3
Publisher: RILEM Publications SARL
Publication year: 2019
Pages: 590-597
Total Pages: 8
Language : English

Abstract: This work aims to develop innovative cementitious solutions for stabilization/solidification process of tunnel boring muds. These muds are characterized by a high CaCO3 content, a high water content and a relatively high fineness, where the material fraction smaller than 80 μm represents almost 50% of its mass. Our interest mainly focuses on the study of alkali-activated slag binders based on sodium hydroxide and sodium metasilicate, both used in powder forms. These two specific binders were compared with regular cements such as ordinary Portland and slag blended cements. Compressive strengths measurements up to 28 days were coupled with a one week long isothermal calorimetry test. Pore solution extraction and analysis were also performed to evaluate binders’ performance at early age and up to 28 days. Soda- activated slag binder showed the highest suitability for the targeted application, both in terms of mechanical properties and chemical reactivity. On the other hand, the use of sodium metasilicate significantly delayed reactivity whereas this binder showed higher mechanical performance compared to sodium hydroxide activated system when used in normalized mortars. Hypothesis regarding the activator interactions with the mud solid matrix and the high water content of the samples are then proposed.

Online publication : 2019
Publication type : full_text
Public price (Euros) : 0.00