Mechanical Properties of MiniBars™ Basalt Fiber-Reinforced Geopolymer Composites

• Published in: Materials Vol. 17; no. 1; p. 248
• Main Authors: Furtos, Gabriel, Prodan, Doina, Sarosi, Codruta, Moldovan, Marioara, Korniejenko, Kinga, Miller, Leonard, Fiala, Lukáš, Iveta, Nováková
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 02.01.2024; MDPI
• Subjects: Basalt; Caustic soda; Cement; Crack propagation; Fiber composites; Flexural strength; Fly ash; Geopolymers; Green buildings; Industrial plant emissions; Investigations; Mechanical properties; Modulus of elasticity; Modulus of rupture in bending; Morphology; Optical microscopy; Optical properties; Polymers; Portland cements; Scanning electron microscopy; Sodium; Sodium silicates; Tensile strength; United Kingdom > UK; Romania; basalt fiber; fly ash; geopolymer composites; MiniBars; mechanical properties
• DOI: 10.3390/ma17010248
• ISSN: 1996-1944

Fly ash-based geopolymers represent a new material, which can be considered an alternative to ordinary Portland cement. MiniBars™ are basalt fiber composites, and they were used to reinforce the geopolymer matrix for the creation of unidirectional MiniBars™ reinforced geopolymer composites (MiniBars™ FRBCs). New materials were obtained by incorporating variable amount of MiniBars™ (0, 12.5, 25, 50, 75 vol.% MiniBars™) in the geopolymer matrix. Geopolymers were prepared by mixing fly ash powder with Na2SiO3 and NaOH as alkaline activators. MiniBars™ FRBCs were cured at 70 °C for 48 h and tested for different mechanical properties. Optical microscopy and SEM were employed to investigate the fillers and MiniBars™ FRBC. MiniBars™ FRBC showed increasing mechanical properties by an increased addition of MiniBars™. The mechanical properties of MiniBars™ FRBC increased more than the geopolymer wtihout MiniBars™: the flexural strength > 11.59–25.97 times, the flexural modulus > 3.33–5.92 times, the tensile strength > 3.50–8.03 times, the tensile modulus > 1.12–1.30 times, and the force load at upper yield tensile strength > 4.18–7.27 times. SEM and optical microscopy analyses were performed on the fractured surface and section of MiniBars™ FRBC and confirmed a good geopolymer network around MiniBars™. Based on our results, MiniBars™ FRBC could be a very promising green material for buildings.