Experimental investigation on the study of mechanical and microstructural properties of hybrid composite cement beams reinforced with multi-walled carbon nanotubes and carbon fibres

Abstract

This paper investigates the behavior of reinforced cement composite beams with multi-walled carbon nanotubes and carbon fibers. The percentage of carbon fibers was fixed at 0.25 wt% of cement, while the percentage of multi-walled carbon nanotubes was fixed at 0.75 wt% of cement. Dispersion of both multi-walled carbon nanotubes and carbon fibers was carried out using the ultrasonic energy method. Composite beams were tested under flexure in order to evaluate their mechanical properties such as flexural strength, toughness and ductility. These results were then compared with the results of plain cement control beams. Microstructural tests like scanning electron microscopy, thermo gravimetric analysis and energy dispersive X-ray analysis were conducted on hybrid nanocomposite material, to study the dispersion of carbon nanotubes and carbon fibers, bonding of carbon nanotubes in C-S-H, temperature effects and the elemental composition. From the study it is concluded that the load-carrying capacity of composite beams under three-point loading is substantially higher than for plain controlled beams.