Speaker
Description
Abstract: Hydration phenomena of a commercial white calcium aluminate cement (CAC (Górkal 70); Al2O3 – 69–72%) at 20°C was modified by adding silica nanoparticles addition in varying amounts and additives in the context of using CACs in the aspiration to achieve climate neutrality and the goal of net zero. The hydration process of CAC modified with silica sol (SS) was tracked by heat flow calorimetry, XRD and SEM experiments supplemented by mechanical strength determination at different curing ages. The findings demonstrate the potential to modify the traditional early (24 hours) hydration pathway of CAC-based systems by both SS and additives, leading to an accelerated process, in terms of the second exothermic peak of paste, and improved mechanical strength, even though no crystalline hydrates were formed. The results indicate that the evolution of the hydration is closely related to the effect of the SS content and additives on the densification and microstructure properties. CAC-based mortar containing 5 wt.% SS and additives exhibited the highest compressive strength, suggesting that early strength development may be attributed to silica nanoparticles acting as a filler. It is also evident that silica sol promotes the formation of CAH10 rather than C2AH8. All binder systems remain strength increase when exposed to 28-days curing conditions.
Affiliations
Vilnius Gediminas Technical University, Linkmenu str 28, Vilnius 08217, Lithuania
Corresponding Author renata.boris@vilniustech.lt
AGH University of Kraków, A. Mickiewicza ave 30, Kraków 30-059, Poland
| Keywords | calcium aluminate cement, silica sol, hydration, microstructure, X-ray diffraction |
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