Experimental study on mechanical properties of raw bamboo fibre-reinforced concrete

Bamboo is an eco-friendly renewable material with a high mechanical performance and short maturation period. The high tensile strength of the raw bamboo fibre is an essential factor for outstanding bamboo properties. In this study, to directly utilize the high tensile strength, the raw bamboo fibre was added to concrete as a reinforcing material. The influence of fibre dosage, length, and maximum aggregate size was systematically studied on the compressive strength, splitting tensile strength, flexural strength, and fracture energy from a macro perspective. In addition, through scanning electron microscopy (SEM), the interfacial bonding between the bamboo fibre and the concrete was further analyzed from a microscopic aspect. The results indicated that the raw bamboo fibre could effectively change the brittle failure mode of the plain concrete. A moderate fibre content, 20 mm fibre length, and 10 mm maximum aggregate size most notably improved the splitting tensile strength and fracture energy, with an increase of 19.8 % and 89.5 %, respectively. From the microscopic aspect, the rough surface structure was conducive to the adsorption of cement hydration products, and hence, improved the mechanical properties and deformation capacity of the raw bamboo fibre-reinforced concrete. • A natural raw bamboo fibre was used to form biomass fibre-reinforced concrete. • Fibre reinforcing mechanism was analyzed at both macroscopic and microscopic scales. • Bridging effect improves mechanical properties of the biomass-based concrete. • Rough surface of raw bamboo fibre was conducive to forming hydration product.