Microstructural Observations on the Durability of Stabilized Rammed Earth
DOI:
https://doi.org/10.56294/sctconf2024827Keywords:
: Rammed Earth, Microstructure, ; Geopolymer.Abstract
This study provides a qualitative microstructural investigation of fly ash geopolymers' role in rammed earth's durability against water ingress and contact erosion. A series of SEM (scanning electron microscopy) images were captured on geopolymer-stabilized as well as unstabilized rammed earth samples. These samples were fabricated from predefined amounts of sand and fine materials together with fly ash geopolymers in the laboratory by static compaction to 25 MPa inside rigid molds. Two standardized durability tests were performed, namely, the dip test and the spray (also known as erosion) test. The results of these tests reflected excellent durability properties (practically zero erosion) of the stabilized material. The microscopic investigation provided an insight into the reason behind this improvement, where geopolymer networks inhabited the macro and micro pores and served as a cementing agent interconnecting the earthen materials’ grains. On the contrary, grains of the unstabilized material were weakly bonded by the clay component of the mixture, as observed with the SEM images; therefore, they were more susceptible to erosion by water
References
1. A. Fabbri, et al., Testing and characterisation of earth-based building materials and elements. 2022: Springer.
2. A.T. Entidhar, N. Al-Ansari, and S. Knutsson, Progress of building materials and foundation engineering in ancient Iraq. Advanced Materials Research, 2012. 446: p. 220-241.
3. C. Beckett, and S. THOMAS, The role of material structure in compacted earthen building materials: implications for design and construction. 2011, Durham university.
4. B. Khadka, Rammed earth, as a sustainable and structurally safe green building: a housing solution in the era of global warming and climate change. asian journal of civil engineering, 2020. 21(1): p. 119-136.
5. K. Heathcote, Durability of earthwall buildings. Construction and building materials, 1995. 9(3): p. 185-189.
6. A. Arrigoni, et al., Life cycle analysis of environmental impact vs. durability of stabilised rammed earth. Construction and Building Materials, 2017. 142: p. 128-136.
7. P. Walker, The Australian earth building handbook, in The Australian Earth Building Handbook. 2002, SAI Global Limited.
8. P. Narloch, and P. Woyciechowski, assessing cement stabilized rammed earth durability in a humid continental climate. Buildings, 2020. 10(2): p. 26.
9. Standard, N.Z., NZS 4298: 1998: Materials and workmanship for earth buildings (1998). 2022.
10. C. Beckett, and D. Ciancio, Durability of cement-stabilised rammed earth: A case study in Western Australia. Australian Journal of Civil Engineering, 2016. 14(1): p. 54-62.
11. Q.-B. Bui, et al., Durability of rammed earth walls exposed for 20 years to natural weathering. Building and Environment, 2009. 44(5): p. 912-919.
12. P. Sargent, The development of alkali-activated mixtures for soil stabilisation, in Handbook of alkali-activated cements, mortars and concretes. 2015, Elsevier. p. 555-604.
13. N. Cristelo, et al., Effect of calcium content on soil stabilisation with alkaline activation. Construction and Building Materials, 2012. 29: p. 167-174.
14. Z. Liu, et al., Feasibility study of loess stabilization with fly ash–based geopolymer. Journal of Materials in Civil Engineering, 2016. 28(5): p. 04016003.
15. I. Phummiphan, et al., Stabilisation of marginal lateritic soil using high calcium fly ash-based geopolymer. Road Materials and Pavement Design, 2016. 17(4): p. 877-891.
16. H.H. Abdullah, M.A. Shahin, and M.L. Walske, Geo-mechanical behavior of clay soils stabilized at ambient temperature with fly-ash geopolymer-incorporated granulated slag. Soils and Foundations, 2019. 59(6): p. 1906-1920.
17. S.S. Yahya, M.A. AL-Sharrad, Preparation of Rammed Earth Material Stabilized with Fly Ash Geopolymer. in Accepted for publishing in The 5th International Conference on Buildings, Construction and Environmental Engineering(BCEE5). 2023. Amman-Jordan.
18. E.V. Deutsches Institute Fur Normung (German National Standard), DIN 18945, Earth Blocks – Terms and Definitions, Requirements, TestMethods. 2013 Aug.
19. J.A.N.Z.T. Committee, NZS 4298 (1998): Materials and workmanship for earth buildings. Materials and workmanship for earth buildings. Standards New Zealand, 1998.
20. E.L. Hasan, M.A. AL-Sharrad, Suitability of earthen materials for rammed earth in arid region. Accepted for publishing in the Magazine Of Civil Engineering, 2023: p. 13.
21. J. Davidovits, Geopolymer chemistry and applications. Institut Géopolymère, Geopolymer Institute, Saint-Quentin, France. 2008, ISBN 2-951-14820-1-9.
22. A. Palomo, M. Grutzeck, and M. Blanco, Alkali-activated fly ashes: A cement for the future. Cement and concrete research, 1999. 29(8): p. 1323-1329.
23. Sindhunata, et al., Effect of curing temperature and silicate concentration on fly-ash-based geopolymerization. Industrial & Engineering Chemistry Research, 2006. 45(10): p. 3559-3568.
24. A.C.C.-o. Concrete, and C. Aggregates, Standard specification for coal fly ash and raw or calcined natural pozzolan for use in concrete. 2013: ASTM international.
25. B.V. Rangan, et al. Studies on fly ash-based geopolymer concrete. in Proceedings of the world congress geopolymer, Saint Quentin, France. 2005.
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Copyright (c) 2024 Soura S. Yahya , Muayad A. Al-Sharrad (Author)
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