Thermo-mechanical and moisture absorption properties of fly ash-based lightweight geopolymer concrete reinforced by polypropylene fibers

Wang, Yijiang; Zheng, Tongda; Zheng, Xiaofeng; Liu, Yifei; Darkwa, Jo; Zhou, Guoqing

Abstract

An experimental investigation on the thermo-mechanical and moisture absorption properties of lightweight geopolymer concrete prepared with fly ash, NaOH, sodium silicate and Polypropylene Fibers (PF) is presented in this study. The effects of dry density, NaOH, PF, aggregates and hydrophobic agent on the compressive strength, thermal properties and moisture absorption were studied. Results indicate that thermo-mechanical properties of Fly ash-based Lightweight Geopolymer Concrete (FLGC) strongly depend on the dry density, NaOH, PF and aggregates contents. The increase in dry density and fine aggregate contents resulted in higher compressive strength and thermal conductivity. NaOH within mass ratio of 0–10% is able to enhance thermo-mechanical properties. The optimal compressive strength was achieved when the length and content of the PF was 12 mm and 0.5% respectively. Meanwhile, PF in the range of 0–1% can also increase thermal conductivity and enhance moisture absorption. The increase in coarse aggregate ranging from 0 to 15% led to reduced dry density and thermal conductivity and enhanced moisture absorption, but did not affect compressive strength. Interestingly, the decrease in fine aggregate with the same content had the opposite impact to the moisture absorption in comparison to the coarse aggregate. However, the moisture absorption can be considerably weakened by surface waterproofing treatment which makes the enhanced thermal performance durable. Therefore, the FLGC reinforced by PF has excellent thermo-mechanical properties and can also be engineered to be an environmentally friendly and durable thermal insulation material with the assistance of waterproofing treatment.

Citation

Wang, Y., Zheng, T., Zheng, X., Liu, Y., Darkwa, J., & Zhou, G. (2020). Thermo-mechanical and moisture absorption properties of fly ash-based lightweight geopolymer concrete reinforced by polypropylene fibers. Construction and Building Materials, 251, Article 118960. https://doi.org/10.1016/j.conbuildmat.2020.118960

• Journal Article Type: Article
• Acceptance Date: Mar 31, 2020
• Online Publication Date: Apr 8, 2020
• Publication Date: Aug 10, 2020
• Deposit Date: Apr 22, 2020
• Publicly Available Date: Apr 9, 2021
• Journal: Construction and Building Materials
• Print ISSN: 0950-0618
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 251
• Article Number: 118960
• DOI: https://doi.org/10.1016/j.conbuildmat.2020.118960
• Keywords: General Materials Science; Civil and Structural Engineering; Building and Construction
• Public URL: https://nottingham-repository.worktribe.com/output/4326845
• Publisher URL: https://www.sciencedirect.com/science/article/abs/pii/S095006182030965X
• Additional Information: This article is maintained by: Elsevier; Article Title: Thermo-mechanical and moisture absorption properties of fly ash-based lightweight geopolymer concrete reinforced by polypropylene fibers; Journal Title: Construction and Building Materials; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.conbuildmat.2020.118960; Content Type: article; Copyright: © 2020 Elsevier Ltd. All rights reserved.