Title:
Influence of Cement Type and Curing Conditions on the Flexural Strength and Microstructure of Mortars Reinforced with Sheep Wool Fibers
Author(s):
Daria Jóźwiak-Niedźwiedzka, Alessandro P. Fantilli
Publication:
Symposium Paper
Volume:
355
Issue:
Appears on pages(s):
283-292
Keywords:
Cement; Durability; Fracture toughness; Microstructure analysis; Natural fibers
DOI:
10.14359/51736034
Date:
7/1/2022
Abstract:
Various types of dispersed reinforcement in the form of thin fibers are known to improve the toughness of cement-based materials. In cement-matrix composites, the application of sheep wool, which is an ecological material, annually renewable and completely recyclable, perfectly fits into green and sustainable development. As the wool tends to be damaged by an alkaline environment, this paper describes the influence of the cement type on the performance of sheep wool reinforced mortars. Hence, ordinary Portland cement (CEM I 42.5R), limestone Portland cement (CEM II/B-LL 42.5R), and calcium sulfoaluminate cement (SL05 42.5) are analyzed. The latter is known to be low carbon compared to CEM I. Additionally, two conditions, differing in maturity in high or low humidity, at a constant temperature of 20°C, are used to cure the specimens. As a result, mechanical properties, and flexural toughness in particular, strongly depend on the type of cement and on the curing conditions. This is true both for the mortar specimens reinforced with sheep wool fibers and for those reinforced with polypropylene fibers, herein considered as reference fibers.
Related References:
1. Jóźwiak-Niedźwiedzka, D., Fantilli, A.P., „Wool-reinforced cement-based composites”, Materials, 2020, 13, 3590, pp. 13.
2. Korjenic, A., Klarić, S., Hadžić, A., Korjenic, S., „Sheep wool as a construction material for energy efficiency improvement”, Energies, 2015, 8, 5765‒5781.
3. Kuffner, H., Popescu, C., “Wool fibres”, Chapter 8 in Handbook of Natural Fibres, Types, Properties and Factors Affecting Breeding and Cultivation, Kozłowski, R., Ed., Woodhead Publishing: UK, 2012, pp. 171–195.
4. Wei, J., Meyer, C., “Degradation mechanisms of natural fibre in the matrix of cement composites”, Cement and Concrete Research, 2015, 73, 1–16.
5. Fantilli, A.P., Jóźwiak-Niedźwiedzka, D., “Influence of Portland cement alkalinity on wool reinforced mortar”, Proceedings of the Institution of Civil Engineers-Construction Materials, 2020, 1–27, doi: 10.1680/jcoma.20.00003
6. Bertola, F., Gastaldi, D., Canonico, F., Paul, G., “CSA and SLAG: towards CSA composite binders”, Advances in Cement Research, 2018, 1–41.
7. Janotka, I., Krajči, L., Ray, A., S.C. Mojumdar, S.C., “The hydration phase and pore structure formation in the blends of sulfoaluminate-belite cement with Portland cement”, Cement and Concrete Research 33, 2003, 489–497.
8. EN 196-1:2016, Methods of testing cement. Determination of strength, 2016, pp. 38.
9. Jóźwiak-Niedźwiedzka D., Fantilli A.P., “Cement based composites with multifunctional addition of unused wool fibres” in Energy efficient, sustainable building materials and products, I. Hager Ed., Cracow University of Technology (2017) 267-282.
10. Majumdar, A.J., Singh, B., Ali, M.A., “Properties of high-alumina cement reinforced with alkali resistant glass fibres”, Journal of Materials Science, vol. 16, 1981, 2597-2607.