Durability Performance of Basalt Fiber-Reinforced Concrete Subjected to Sulfate–Magnesium Combined Attack

Autor: Henghui Fan, Cheng Wang, Yiqi Hu, Gaowen Zhao
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Materials, Vol 17, Iss 5, p 1128 (2024)
Druh dokumentu: article
ISSN: 1996-1944
DOI: 10.3390/ma17051128
Popis: In salt lake areas, cast-in situ concrete structures are subjected to long-term corrosion by sulfate and magnesium ions. The properties of concrete can be improved by adding materials like basalt fiber (BF). To investigate the degradation process and mechanism of cast-in situ concrete with premixed BF under the dual corrosion of sulfate and magnesium salts, concrete with a content of BF ranging from 0 to 0.5% was prepared. Specimens were subjected to different internal and external corrosion conditions and immersed for 180 days. Dimension, mass, and appearance changes at different immersion times were recorded. The compressive and flexural strength of the specimens were tested and continually observed throughout the immersion time. Mineral and microstructural changes at different immersion times were determined by the XRD, TG, and SEM analysis methods. Results indicated that external sulfate–internal magnesium combined attack had a significant negative effect on the early strength. The compressive and flexural strength of the corroded specimens decreased by 17.2% and 14.1%, respectively, compared to the control group at 28 days. The premixed magnesium ions caused the decomposition of the C-S-H gel, resulting in severe spalling and lower mechanical properties after immersing for a long time. As the BF can inhibit crack development, the properties of the concrete premixed with BF were improved. Specimens exhibited superior performance at a BF content of 0.5%, resulting in a 16.2% increase in flexural strength. This paper serves as a valuable reference for the application of basalt fiber-reinforced concrete under the challenging conditions of sulfate–magnesium combined attack.
Databáze: Directory of Open Access Journals
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