THE INFLUENCE OF SLAG CHEMISTRY ON BLENDED CEMENTS MADE WITH IRON-RICH SLAG

Author(s): Vincent Hallet (1, 2), Jos Denissen (1), Remus Ion Iacobescu (1), Yiannis Pontikes (1)
Paper category: Proceedings
Book title: SynerCrete’18 International Conference on Interdisciplinary Approaches for Cement-based Materials and Structural Concrete
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: 931-936
Total Pages: 6
Language : English

Abstract: Ordinary Portland cement is often substituted by ground granulated blast furnace slag (GGBFS) in order to adjust the properties and decrease the CO2 emissions of the cement binder. GGBFS is rich in Ca and Si and poor in Fe. On the contrary, non-ferrous metallurgy slags are rich in Fe and Si and poor in Ca. Nonetheless, it is known that Fe3+ could develop hydration products at the expense of Al3+. Therefore, this paper investigates the pozzolanic activity of 3 iron-rich slags with varying content of major oxides, as single components and in blended cements. Slag reactivity was assessed through dissolution tests in 0.1M NaOH solution and by thermogravimetric analysis. Additionally, blended cements with 30 wt% substitution of Portland cement were produced and investigated for the phase assemblage and mechanical strength using quantitative X-ray powder diffraction and compression tests, respectively. Following the characterisations, slags with low (CaO+MgO)/SiO2 weight ratio showed pozzolanic activity, whereas the slag with high (CaO+MgO)/SiO2 weight ratio exhibited more latent hydraulic behaviour. Furthermore, after 90 days of curing, all slag blend formulations had higher compressive strengths than those without slag. This work therefore shows that the Fe-rich slags used in this study are suitable candidates for OPC substitution.

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