Hydration-Control of Ternary Cements for Digital Fabrication with Concrete (2019-09)¶

Das Arnesh, Reiter Lex, Wangler Timothy, Flatt Robert
Contribution - Proceedings of the 2^nd International RILEM Conference on Rheology and Processing of Construction Materials and the 9^th International RILEM Symposium on Self-Compacting Concrete

Abstract

Novel building processes such as layered extrusion with concrete offer both advantages and pose challenges to building materials, one of them being early age strength. In particular, the material needs to sustain its own weight upon placing as well as that of the subsequently deposited layers. If many layers should be built, this involves set acceleration. Ternary blended cementitious systems comprising ordinary Portland cement (OPC), calcium aluminate cement (CAC) and a calcium sulfate source (C$) such as anhydrite (along with appropriate usage of chemical admixtures) could potentially be used to achieve this purpose. In this study, the evolution of rheological properties and progress of hydration of such a ternary cement has been investigated. A CAC paste was used as an accelerator for an OPC-C$ mix, keeping a fixed ratio of CAC to C$ of 2:1 and substituting 5%, 10%, 15% and 20% of the OPC. The progress of hydration and its products were studied using isothermal calorimetry, X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). This was compared to the yield stress evolution as measured with rheometric methods and the results were found to correlate well with each other. It was found that as the dosage of CAC increased in the mixes, more ettringite was formed and this was mainly responsible for the evolution of storage modulus/yield stress. Also, using anhydrite meant that there were no signs of sulphate depletion.

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BibTeX

@inproceedings{das_reit_wang_flat.2019.HCoTCfDFwC,
  author            = "Arnesh Das and Lex Reiter and Timothy Paul Wangler and Robert Johann Flatt",
  title             = "Hydration-Control of Ternary Cements for Digital Fabrication with Concrete",
  year              = "2019",
  booktitle         = "Proceedings of the 2nd International RILEM Conference on Rheology and Processing of Construction Materials and the 9th International RILEM Symposium on Self-Compacting Concrete",
  editor            = "Viktor Mechtcherine and Kamal H. Khayat and Egor Secrieru",
}

Formatted Citation

IEEE

A. Das, L. Reiter, T. P. Wangler and R. J. Flatt, “Hydration-Control of Ternary Cements for Digital Fabrication with Concrete”, in Proceedings of the 2^nd International RILEM Conference on Rheology and Processing of Construction Materials and the 9^th International RILEM Symposium on Self-Compacting Concrete, 2019.

CMOS

Das, Arnesh, Lex Reiter, Timothy Paul Wangler, and Robert Johann Flatt. “Hydration-Control of Ternary Cements for Digital Fabrication with Concrete”. In Proceedings of the 2^nd International RILEM Conference on Rheology and Processing of Construction Materials and the 9^th International RILEM Symposium on Self-Compacting Concrete, edited by Viktor Mechtcherine, Kamal H. Khayat, and Egor Secrieru, 2019.