Hydration and thermal properties of alkaline hybrid cements based on waste clay and solid alkaline activators

Hydration and thermal properties of alkaline hybrid cements based on waste clay and solid alkaline activators

Článek WoS

The cement industry is actively pursuing sustainable alternatives to reduce CO2 emissions and combat climate change. This study focuses on replacing Portland cement (PC) with rotary kiln flue dust (RFD), a byproduct of metakaolin production. The research investigates the viability of using moderately alkaline activators, including Na2SO4, Na2CO3, K2SO4, and K2CO3, to achieve alkali activation without the need for high-temperature calcination, which consumes a lot of energy. The experimental mixtures, comprising 75% RFD, 20% PC, and 5% alkaline activator, exhibit promising results in terms of compressive and flexural strengths. Na2SO4 enhances the mechanical properties of the binder. Synergic effect of alkaline activator and PC accelerate reaction original raw material, leading to the formation of ettringite. Conversely, carbonate activators extend the setting time and delay reactions, impacting the early age properties of the binder. The study also explores the thermal stability of the binders, demonstrating a notable impact of alkaline activators on the expansion and contraction behaviors during heating. The findings contribute with valuable insights into the design and optimization of eco-friendly alkali-activated binders, addressing the need for sustainable construction materials with enhanced performance and durability. This research represents a significant step toward developing environmentally preferable cementitious materials, paving the way for the construction industry to adopt more sustainable practices and reduce its ecological footprint.

The cement industry is actively pursuing sustainable alternatives to reduce CO2 emissions and combat climate change. This study focuses on replacing Portland cement (PC) with rotary kiln flue dust (RFD), a byproduct of metakaolin production. The research investigates the viability of using moderately alkaline activators, including Na2SO4, Na2CO3, K2SO4, and K2CO3, to achieve alkali activation without the need for high-temperature calcination, which consumes a lot of energy. The experimental mixtures, comprising 75% RFD, 20% PC, and 5% alkaline activator, exhibit promising results in terms of compressive and flexural strengths. Na2SO4 enhances the mechanical properties of the binder. Synergic effect of alkaline activator and PC accelerate reaction original raw material, leading to the formation of ettringite. Conversely, carbonate activators extend the setting time and delay reactions, impacting the early age properties of the binder. The study also explores the thermal stability of the binders, demonstrating a notable impact of alkaline activators on the expansion and contraction behaviors during heating. The findings contribute with valuable insights into the design and optimization of eco-friendly alkali-activated binders, addressing the need for sustainable construction materials with enhanced performance and durability. This research represents a significant step toward developing environmentally preferable cementitious materials, paving the way for the construction industry to adopt more sustainable practices and reduce its ecological footprint.

Hybrid alkaline cement, Rotary kiln flue dust, Waste clay, Alkaline activation, Thermal resistance

Hybrid alkaline cement, Rotary kiln flue dust, Waste clay, Alkaline activation, Thermal resistance

KUBATOVA, D.; ZEZULOVA, A.; KOTLANOVA, M.; KŘIVÁNKOVÁ, E.; BOHAC, M.; STANEK, T.

2026

01.01.2025

Springer Nature

Journal of Thermal Analysis and Calorimetry

150

2

Maďarsko

1105

1117

13

https://link.springer.com/article/10.1007/s10973-024-13944-5