Title:
Effectiveness of PCEs in Combination with Isobutyltriethoxy Silane for Slump Retention in Ultra-Low Clinker Binders
Author(s):
Xinyue Wang and Johann Plank
Publication:
Symposium Paper
Volume:
369
Issue:
Appears on pages(s):
91-104
Keywords:
Climate-neutral cement; calcined clay; limestone; workability; slump retention; silanes; polycarboxylate ether PCE; compressive strength; hydration.
DOI:
10.14359/51750724
Date:
5/1/2026
Abstract:
Achieving climate-neutral cement requires drastic clinker substitution; however, ultra-high calcined clay (CC) contents severely impair slump retention and early strength. This study evaluates two practical routes to extend the workability time of binders possessing the same clinker content (20 wt%): (i) admixture modification by adding isobutyltriethoxysilane (IBTEOS) to PCE solutions; and (ii) binder optimization by using a calcined clay–limestone blend (“LC-20”). Mortar tests with three slump-retaining PCEs (neat or in combination with IBTEOS) assessed flowability, slump retention, and 1 – 28 day compressive strength. LC-20 generally required lower PCE dosages and delivered superior slump-retaining performance versus the OPC/CC blend (20:80). IBTEOS markedly improved slump retention — most notably in the OPC/CC system — by hydrophobizing reactive surfaces and reducing early water uptake, thereby enhancing PCE effectiveness. IBTEOS suppressed early strength (no 1-day strength; ~ 50 % decrease vs. silane-free system at 2 days), but the gap narrowed with curing time to ≤ 10 % at 28 days. Some LC-20 mortars holding IBTEOS even surpassed the samples prepared only with PCEs, due to additional silane condensation. Overall, extended workability in low-clinker systems can be achieved either by combining PCEs with IBTEOS or by formulating a ternary binder system holding less calcined clay.
Related References:
1. https://www.europarl.europa.eu/topics/en/article/20190926STO62270/what-is-carbon-neutrality-and-how-can-it-be-achieved-by-2050. retrieved on 6th July 2025.
2. Chen, J. and Plank, J., Calcined clays for climate neutral (“net zero”) cements: shear-dependent rheological behavior and application performance. Cement and Concrete Composites, 2025. p. 106145.
3. Leung, D.Y., Caramanna, G., and Maroto-Valer, M.M., An overview of current status of carbon dioxide capture and storage technologies. Renewable and Sustainable Energy Reviews, 2014. vol. 39: p. 426-443.
4. Scrivener, K.L., John, V.M., and Gartner, E.M., Eco-efficient cements: Potential economically viable solutions for a low-CO2 cement-based materials industry. Cement and Concrete Research, 2018. vol. 114: p. 2-26.
5. Habert, G., Miller, S.A., John, V.M., Provis, J.L., Favier, A., Horvath, A., and Scrivener, K.L., Environmental impacts and decarbonization strategies in the cement and concrete industries. Nature Reviews Earth & Environment, 2020. vol. 1(11): p. 559-573.
6. Jaskulski, R., Jóźwiak-Niedźwiedzka, D., and Yakymechko, Y., Calcined clay as supplementary cementitious material. Materials, 2020. vol. 13(21): p. 4734.
7. Hanein, T., et al., Clay calcination technology: state-of-the-art review by the RILEM TC 282-CCL. Materials and Structures, 2022. vol. 55(1): p. 3.
8. Shao, J., Guo, S., and Wang, H., A Review of the Performance, Sustainable Applications, and Research Challenges of Limestone-Calcined Clay-Cement (LC3) Systems. Coatings, 2025. vol. 15(5): p. 611.
9. Nair, N., Haneefa, K.M., Santhanam, M., and Gettu, R., A study on fresh properties of limestone calcined clay blended cementitious systems. Construction and Building Materials, 2020. vol. 254: p. 119326.
10. Li, R., Lei, L., Sui, T., and Plank, J., Approaches to achieve fluidity retention in low-carbon calcined clay blended cements. Journal of Cleaner Production, 2021. vol. 311: p. 127770.
11. Moghul, S., Zunino, F., and Flatt, R.J., Flow loss in superplasticized limestone calcined clay cement. Journal of the American Ceramic Society, 2025. vol. 108(5): p. e20344.
12. Zunino, F. and Scrivener, K., Microstructural developments of limestone calcined clay cement (LC3) pastes after long-term (3 years) hydration. Cement and Concrete Research, 2022. vol. 153: p. 106693.
13. Singh, N., Effect of gluconates on the hydration of cement. Cement and Concrete Research, 1976. vol. 6(4): p. 455-460.
14. Ma, S., Li, W., Zhang, S., Ge, D., Yu, J., and Shen, X., Influence of sodium gluconate on the performance and hydration of Portland cement. Construction and Building Materials, 2015. vol. 91: p. 138-144.
15. Sha, S., Wang, M., Shi, C., and Xiao, Y., Influence of the structures of polycarboxylate superplasticizer on its performance in cement-based materials - A review. Construction and Building Materials, 2020. vol. 233: p. 117257.
16. Yamada, K., Takahashi, T., Hanehara, S., and Matsuhisa, M., Effects of the chemical structure on the properties of polycarboxylate-type superplasticizer. Cement and Concrete Research, 2000. vol. 30(2): p. 197-207.
17. Gao, Y., Zhao, H., Chen, G., Peng, Q., Liu, Y., Song, F., and Liu, Q., Influence of Pentaerythritol Tetraacrylate Crosslinker on Polycarboxylate Superplasticizer Performance in Cementitious System. Materials, 2022. vol. 15(4): p. 1524.
18. Liu, H., Pang, H., Ou, J., Zhang, L., Dai, Y., and Liao, B., Effect of cross-linked polycarboxylate-type superplasticizers on the properties in cementitious system. Journal of Applied Polymer Science, 2014. vol. 131(19).
19. Zhang, L., Kong, X., Xing, F., Dong, B., and Wang, F., Working mechanism of post-acting polycarboxylate superplasticizers containing acrylate segments. Journal of Applied Polymer Science, 2018. vol. 135(5): p. 45753.
20. Guo, G., Wu, S., Liu, G., Zhang, F., and Wang, L., Synthesis and Performance of HPEG-AA-AMPS-HPA Polycarboxylate Superplasticizer. Journal of Physics: Conference Series, 2024. vol. 2737(1): p. 012007.
21. He, Y., Zhang, X., and Hooton, R., Effects of organosilane-modified polycarboxylate superplasticizer on the fluidity and hydration properties of cement paste. Construction and Building Materials, 2017. vol. 132: p. 112-123.
22. Wang, M. and Yao, H., A Novel Organic–Inorganic Hybrid Admixture for Increasing Flowability and Reducing Viscosity of Ultra-High Performance Paste. Materials, 2020. vol. 13(15): p. 3385.
23. Wang, R., Han, K., Li, Y., and Jin, C., A novel anti-clay silane-modified polycarboxylate superplasticizer: Preparation, performance and mechanism. Construction and Building Materials, 2022. vol. 331: p. 127311.
24. Lu, Z., Kong, X., Liu, H., Wang, Z., Zhang, Y., Dong, B., and Xing, F., Interaction of silylated superplasticizers with cementitious materials. Journal of Applied Polymer Science, 2016. vol. 133(43).
25. Plank, J., Yang, F., and Storcheva, O., Study of the interaction between cement phases and polycarboxylate superplasticizers possessing silyl functionalities. Journal of Sustainable Cement-Based Materials, 2014. vol. 3(2): p. 77-87.
26. Zhang, C., Hu, Z., Zhu, H., Wang, X., and Gao, J., Effects of silane on reaction process and microstructure of metakaolin-based geopolymer composites. Journal of Building Engineering, 2020. vol. 32: p. 101695.
27. Antoni, M., Rossen, J., Martirena, F., and Scrivener, K., Cement substitution by a combination of metakaolin and limestone. Cement and concrete research, 2012. vol. 42(12): p. 1579-1589.
28. Akhlaghi, O., et al., Modified poly (carboxylate ether)-based superplasticizer for enhanced flowability of calcined clay-limestone-gypsum blended Portland cement. Cement and Concrete Research, 2017. vol. 101: p. 114-122.
29. Zunino, F. and Scrivener, K., The reaction between metakaolin and limestone and its effect in porosity refinement and mechanical properties. Cement and Concrete Research, 2021. vol. 140: p. 106307.
30. Chen, J. and Plank, J., Alkali-activated calcined clay blended cement: Effect of NaOH activator on performance of HPEG PCEs and on early strength. Cement and Concrete Research, 2024. vol. 183: p. 107588.
31. Pott, U., et al., Characterization data of reference materials used for phase II of the priority program DFG SPP 2005 “Opus Fluidum Futurum-Rheology of reactive, multiscale, multiphase construction materials”. Data in Brief 47. 2023.
32. EN196-1:2016, Methods of testing cement - Part 1: Determination of strength. Berlin, Germany: German Institute for Standardization (DIN e. V.).
33. Lothenbach, B., Scrivener, K., and Hooton, R., Supplementary cementitious materials. Cement and concrete research, 2011. vol. 41(12): p. 1244-1256.
34. Wang, X. and Plank, J., A Silane Admixture to Achieve Slump Retention in Ultra-High Calcined Clay Blended Cement. Cement and Concrete Research, under review.
35. Cheung, J., Jeknavorian, A., Roberts, L., and Silva, D., Impact of admixtures on the hydration kinetics of Portland cement. Cement and Concrete Research, 2011. vol. 41(12): p. 1289-1309.
36. Chen, B., Shao, H., Li, B., and Li, Z., Influence of silane on hydration characteristics and mechanical properties of cement paste. Cement and Concrete Composites, 2020. vol. 113: p. 103743.
37. Yang, J., Zuo, W., and She, W., Towards a further understanding of cement hydration at the early-age stage in the presence of hydrophobic silane IBTEO. Cement and Concrete Composites, 2024. vol. 153: p. 105712.