Sulphate-induced corrosion of steel reinforcement in fresh calcium sulphoaluminate binders: preliminary studies

Author(s): Yegor Morozov, Simone Pellegrini, Sergio Lorenzi, Fátima Montemor
Paper category: Proceedings
Book title: SynerCrete’18: Interdisciplinary Approaches for Cement-based Materials and Structural Concrete: Synergizing Expertise and Bridging Scales of Space and Time Vol. 1 & 2
Editor(s): Miguel Azenha, Dirk Schlicke, Farid Benboudjema, Agnieszka Jędrzejewska
ISBN: 978-2-35158-202-2
e-ISBN: 978-2-35158-203-9
Publisher: RILEM Publications SARL
Publication year: 2018
Pages: 339-344
Total Pages: 6
Language : English

Abstract: Ordinary Portland cement (OPC) production is the largest contributor to global emissions. Main strategies to reduce the environmental impact include optimization of clinker production and grinding, usage of alternative fuels and raw materials, and, finally, shift to blended cements. Nevertheless, such measures can shorten emissions just for 30-40 %, thus, alternative binders and their mixtures with OPC are recently in focus. Among those, calcium sulphoaluminate cements (CSA) are attractive for emissions minimization, and show unique properties, but they lack durability studies and the understanding of embedded steel reinforcement behaviour.
The corrosion behaviour of steel was tentatively tested in solutions that simulate liquid phase at various stages of binder hydration. In static tests, steel samples were immersed in solutions of constant composition, while in dynamic tests it was changed to mimic the evolution of key parameters, i.e. pH and sulphates, in a way it happens during binder hydration. The preliminary results suggested that the corrosion of plain mild steel reinforcement would start instantly in CSA binders upon water addition, due to simultaneously low pH and high sulphate concentration, and, despite favourable conditions in hydrated state, corrosion would proceed further, since no long-term repassivation was observed.

Online publication : 2018
Publication type : full_text
Public price (Euros) : 0.00