Title:
Rheological Behaviour of Cement Pastes with Low Amounts of Polynaphthalene Sulfonate Plasticizer
Author(s):
Alexander Mezhov, Simon Ulka, Charles. E. Diesendruck, Youri Gendel, and Konstantin Kovler
Publication:
Symposium Paper
Volume:
326
Issue:
Appears on pages(s):
13.1-13.10
Keywords:
adsorption; low dosage admixture; plasticizer efficiency; polynaphthalene sulfonate (PNS); rheology; yield stress
DOI:
10.14359/51710983
Date:
8/10/2018
Abstract:
In this manuscript, the behaviour of cement pastes is examined when exposed to small additions of three different Polynaphthalene Sulfonate (PNS) based plasticizing admixtures. The adsorption behaviour of the polymeric molecules onto the cement particles is studied, and the minimum dosage of admixture required to achieve a significant change in the paste’s yield stress is measured together with the amount of an entrapped air. Below a minimum PNS dosage, there is no significant change in the yield stress and the amount of air in the paste. Yet, beyond this minimum dosage, both the viscosity and the yield stress decrease steadily and the amount of the entrapped air increases. Interestingly, one of the PNS admixtures exhibited a slower plasticizing effect (i.e. a higher critical dosage) than two others studied PNS compounds.
Related References:
1. P.-C. Ai¨tcin and R. J. Flatt, Science and technology of concrete admixtures, 1st ed. Woodhead Publishing Series in Civil and Structural Engineering: Number 59, 2015.
2. N. Roussel, “Correlation between yield stress and slump: Comparison between numerical simulations and concrete rheometers results,” Mater. Struct., V. 39, 2006, pp. 501–509.
3. N. Roussel, “From industrial testing to rheological parameters for concrete,” in Understanding the Rheology of Concrete, Elsevier, 2012, pp. 83–95.
4. E. Secrieru, S. Fataei, C. Schröfl, and V. Mechtcherine, “Study on concrete pumpability combining different laboratory tools and linkage to rheology,” Constr. Build. Mater., V. 144, 2017, pp. 451–461.
5. M. Collepardi, “Admixtures used to enhance placing characteristics of concrete,” Cem. Concr. Compos., V. 20, No. 2–3, 1998, pp. 103–112.
6. B. G. Kim, S. Jiang, C. Jolicoeur, and P. C. Ai¨tcin, “Adsorption behavior of PNS superplasticizer and its relation to fluidity of cement paste,” Cem. Concr. Res., V. 30, No. 6, 2000, pp. 887–893.
7. Y. Zhang and X. Kong, “Correlations of the dispersing capability of NSF and PCE types of superplasticizer and their impacts on cement hydration with the adsorption in fresh cement pastes,” Cem. Concr. Res., V. 69, 2015, pp. 1–9.
8. J. A. Lewis, H. Matsuyama, G. Kirby, S. Morissette, and J. F. Young, “Polyelectrolyte effects on the rheological properties of concentrated cement suspensions,” J. Am. Ceram. Soc., V. 83, 2000, pp. 1905–1913.
9. Y. F. Houst et al., “Design and function of novel superplasticizers for more durable high performance concrete (superplast project),” Cem. Concr. Res., V. 38, No. 10, 2008, pp. 1197–1209.
10. H. Uchikawa, S. Hanehara, and D. Sawaki, “The role of steric repulsive force in the dispersion of cement particles in fresh paste prepared with organic admixture,” Cem. Concr. Res., V. 27, No. 1, 1997, pp. 37–50.
11. L. J. Struble and Q. Jiang, “Effects of Air Entrainment on Rheology,” ACI Mater. J., V. November-D, No. 101, 2005, pp. 448–456.
12. P. F. G. Banfill, “Rheology of Fresh Cement and Concrete,” Rheol. Rev., V. 2006, pp. 61–130, 2006.
13. W. Feng, J. Xu, P. Chen, L. Jiang, Y. Song, and Y. Cao, “Influence of polycarboxylate superplasticizer on chloride binding in cement paste,” Constr. Build. Mater., V. 158, 2018, pp. 847–854.