Speaker
Description
Specialty binders for premium drymix products commonly consist of a “ternary” blend of calcium aluminate, calcium sulfate and Portland cement. Target performance for each application is achieved by carefully tuning the relative proportions of these constituents together as well as the type & dosage of several set regulators. Simple substitution of CEM I by a blended Portland cement to lower carbon footprint therefore perturbs this balance and can be counterproductive — altering paste rheology, surface appearance and early strength that are critical for drymix formulations — unless the mix design is re-optimized.
Because the clinker content of the overall drymix largely governs its carbon footprint, we present several low-clinker mix designs that preserve or improve key functional properties while reducing footprint by 35%–40% relative to reference formulations.
We further investigate the effect of metakaolin (MK) on these mix-designs, beyond its pozzolanic contribution, and demonstrate a direct beneficial effect of MK on surface quality and abrasion resistance of self-leveling compounds formulated with these designs. Microstructural and phase analyses combined with rheological characterization elucidate the role of MK and its influence on early-age properties, workability and strength development. The results indicate viable pathways to substantially lower clinker content in premium drymix products, while improving the set of performance of the ternary binders.
Affiliations
IMERYS Technology Center, 1 rue le Chatelier, 38090 Vaulx-Milieu
alexandre.franceschini@imerys.com
| Title | Beyond Pozzolanicity: Metakaolin is key to the Surface Aspect of Sustainable Flooring Mortars based on Ternary binders |
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| Keywords | Ternary binder, metakaolin, carbon footprint |