Title:
Influence of the Polymer Structure on the Rheology of Portland Cement and LC3 Pastes Containing Superplasticizers
Author(s):
Torben Gädt, Simon Nickl
Publication:
Symposium Paper
Volume:
362
Issue:
Appears on pages(s):
240-248
Keywords:
calorimetry; chemical admixtures; LC3; slump flow; superplasticizer
DOI:
10.14359/51740886
Date:
6/5/2024
Abstract:
Calcined clays are a very promising supplementary cementitious material. A remaining challenge for a widespread application is the rheology of calcined clay containing cementitious materials. The water and superplasticizer demand and the viscosity of calcined clay binders are higher than for normal Portland cement (PC) binders. Consequently, there is a need to improve the understanding of the rheological properties of calcined clay-based binders. Here, we report on the rheological characteristics of four polycarboxylate ether superplasticizers in Portland cement and LC3 pastes. The superplasticizer chemistry is controlled through polymer synthesis. We chose simple slump flow tests to characterize the rheology of the pastes at different superplasticizer dosages. Furthermore, we characterize the initial reactivity of the binder using in-situ calorimetry. All four polymers exhibit very similar properties in the LC3 system, while the differences are much more prominent in Portland cement. The dosage efficiency in the LC3 system is lower for all polymers, and the most dosage-efficient superplasticizer in the LC3 system is only ranked third in Portland cement. Finally, the very early heat flow of the suspensions indicates that dissolution and early hydrate phase formation of the PC are promoted in LC3 systems. We propose that the increased PC reactivity is partly responsible for the larger slump loss of LC3 binders.
Related References:
1. R. Snellings, P. Suraneni, J. Skibsted, “Future and Emerging Supplementary Cementitious Materials”, Cement and Concrete Research, V. 171, 2023, p. 107199.
2. K. Scrivener, F. Martirena, S. Bishnoi, S. Maity, “Calcined Clay Limestone Cements (LC3)”, Cement and Concrete Research, V. 114, 2018, p. 49–56.
3. R.J. Flatt, N. Roussel, H. Bessaies-Bey, L. Caneda-Martínez, M. Palacios, F. Zunino, “From Physics to Chemistry of Fresh Blended Cements”, Cement and Concrete Research, V. 172, 2023, p. 107243.
4. M. Schmid, J. Plank, “Interaction of Individual Meta Clays with Polycarboxylate (PCE) Superplasticizers in Cement Investigated via Dispersion, Zeta Potential and Sorption Measurements”, Applied Clay Science, V. 207, 2021, p. 106092.
5. M. Maier, R. Sposito, N. Beuntner, K.-C. Thienel, “Particle Characteristics of Calcined Clays and Limestone and Their Impact on Early Hydration and Sulfate Demand of Blended Cement”, Cement and Concrete Research, V. 154, 2022, p. 106736.
6. R. Hay, K. Celik, “Effects of Water-to-Binder Ratios (w/b) and Superplasticizer on Physicochemical, Microstructural, and Mechanical Evolution of Limestone Calcined Clay Cement (LC3)”, Construction and Building Materials, V. 391, 2023, p. 131529.
7. B. Lorentz, H. Zhu, D. Mapa, K.A. Riding, A. Zayed, “Effect of Clay Mineralogy, Particle Size, and Chemical Admixtures on the Rheological Properties of CCIL and CCI/II Systems”, in: Calcined Clays for Sustainable Concrete, Springer, Singapore, 2020, pp. 211–218.
8. Y. Demeusy, C. Labbez, others, “Paste Rheology and Surface Charge of Calcined Kaolinite”, in: 16th International Congress on the Chemistry of Cement 2023 (ICCC 2023), 2023, pp. 77–80.
9. R. Sposito, N. Beuntner, K.-C. Thienel, “Characteristics of Components in Calcined Clays and Their Influence on the Efficiency of Superplasticizers”, Cement and Concrete Composites, V. 110, 2020, p. 103594.
10. R. Li, L. Lei, T. Sui, J. Plank, “Effectiveness of PCE Superplasticizers in Calcined Clay Blended Cements”, Cement and Concrete Research, V. 141, 2021, p. 106334.
11. M. Schmid, J. Plank, “Dispersing performance of different kinds of polycarboxylate (PCE) superplasticizers in cement blended with a calcined clay”, Construction and Building Materials, V. 258, 2020, p. 119576.
12. O. Akhlaghi, T. Aytas, B. Tatli, D. Sezer, A. Hodaei, A. Favier, K. Scrivener, Y.Z. Menceloglu, O. Akbulut, “Modified Poly(Carboxylate Ether)-Based Superplasticizer for Enhanced Flowability of Calcined Clay-Limestone-Gypsum Blended Portland Cement”, Cement and Concrete Research, V. 101, 2017, p. 114–122.
13. I. Bhandari, R. Kumar, “Effect of Silica Fume and PCE-HPMC on LC3 Mortar: Microstructure, Statistical Optimization and Life Cycle Assessment”, Construction and Building Materials, V. 403 2023, p. 133073.
14. S. Ferreiro, D. Herfort, J.S. Damtoft, “Effect of Raw Clay Type, Fineness, Water-to-Cement Ratio and Fly Ash Addition on Workability and Strength Performance of Calcined Clay Limestone Portland Cements”, Cement and Concrete Research, V. 101, 2017, p. 1–12.
15. T.R. Muzenda, P. Hou, S. Kawashima, T. Sui, X. Cheng, “The Role of Limestone and Calcined Clay on the Rheological Properties of LC3”, Cement and Concrete Composites, V. 107, 2020, p. 103516.
16. M.A.B. Beigh, V.N. Nerella, C. Schröfl, V. Mechtcherine, “Studying the Rheological Behavior of Limestone Calcined Clay Cement (LC3) Mixtures in the Context of Extrusion-Based 3D-Printing”, Calcined Clays for Sustainable Concrete, V. 25, 2020, p. 229–236.
17. N. Nair, K. Mohammed Haneefa, M. Santhanam, R. Gettu, “A Study on Fresh Properties of Limestone Calcined Clay Blended Cementitious Systems”, Construction and Building Materials, V. 254, 2020, p.119326.
18. R. Sposito, M. Maier, N. Beuntner, K.-C. Thienel, “Physical and mineralogical properties of calcined common clays as SCM and their impact on flow resistance and demand for superplasticizer”, Cement and Concrete Research, V. 154, 2022, p. 106743.
19. K.L. Scrivener, V.M. John, E.M. Gartner, “Eco-Efficient Cements: Potential Economically Viable Solutions for a Low-CO2 Cement-Based Materials Industry”, Cement and Concrete Research, V. 114, 2018, p. 2–26.
20. D. Axthammer, M. Ordynska, T. Gädt, “C3A Variation in Synthetic Model Cements ‐ Influence on Rheology and Reactivity”, ce papers 6, 2023, p. 670–676.