T. Alomayri

Effect of water absorption on the mechanical properties of cotton fabric-reinforced geopolymer composites

Abstract Cotton fabric (CF) reinforced geopolymer composites are fabricated with fibre loadings of 4.5, 6.2 and 8.3 wt%. Results show that flexural strength, flexural modulus, impact strength, hardness and fracture toughness are increased as the fibre content increased. The ultimate mechanical properties were achieved with a fibre content of 8.3 wt%. The effect of water absorption on mechanical and physical properties of CF reinforced geopolymer composites is also investigated. The magnitude of maximum water uptake and diffusion coefficient is increased with an increase in fibre content. Flexural strength, modulus, impact strength, hardness and fracture toughness values are decreased as a result of water absorption. Scanning electron microscopy (SEM) is used to characterise the microstructure and failure mechanisms of dry and wet cotton fibre reinforced geopolymer composites.

Synthesis and characterization of mechanical properties in cotton fiber-reinforced geopolymer composites

Abstract Geopolymers are inorganic aluminosilicate materials that possess relatively good mechanical properties and desirable thermal stability but they exhibit failure behavior similar to brittle solids. This limitation may be remedied by fiber reinforcement to improve their strength and toughness. This paper describes the synthesis of cotton fiber-reinforced geopolymer composites and the characterization of their mechanical properties. The effects of cotton fiber content (0–1.0 wt.%) and fiber dispersion on the mechanical characteristics of geopolymer composites have been investigated in terms of hardness, impact strength and compressive strength. A fiber content of 0.5 wt.% was observed for achieving optimum mechanical properties in these composites.

Mechanical properties of cotton fabric reinforced geopolymer composites at 200–1000 ℃

Geopolymer composites containing woven cotton fabric (0–8.3 wt%) were fabricated using the hand lay-up technique, and were exposed to elevated temperatures of 200 °C, 400 °C, 600 °C, 800 °C and 1000 °C. With an increase in temperature, the geopolymer composites exhibited a reduction in compressive strength, flexural strength and fracture toughness. When heated above 600 °C, the composites exhibited a significant reduction in mechanical properties. They also exhibited brittle behavior due to severe degradation of cotton fibres and the creation of additional porosity in the composites. Microstructural images verified the existence of voids and small channels in the composites due to fibre degradation.