Waste feather fibre reinforcement for cement-based materials

Abstract

The poultry production industry is an economically important agriculture-based activity worldwide. The industry leads to the production of significant waste including large quantities of feathers with challenges associated with disposal. Keratin-rich feather fibre can be used in an innovative way as reinforcement in cement-based construction materials such as low-impact concrete addressing the principles of circular economy. Feathers have been utilised in different ways; as whole fibres, hand-cut rachis, ground fibres and a combination of both feather fibres and ground feathers. Feather fibre cement-based materials have been used for the creation of feather-board as a low-cost material which can be utilised for non-structural applications. Investigations in feather fibre cement-based materials also refer to the effect on mechanical characteristics, setting time and hydration characteristics. The research project objective is to reutilise the biomaterial which would have otherwise reach its end-of-life stage. This study investigates the potential use of feather fibres in cement-based materials including self compacting concrete and the effect on the fresh properties, early age characteristics and hardened properties including mechanical and durability properties. An operating procedure was developed including washing and shredding, to transform the feathers into a product ready for inclusion in concrete. The effects of different fibre lengths with varying fibre volume percentages were considered in the concrete mixes. An experimental investigation was conducted to assess the fresh properties, with reference to empirical tests and rheology. The introduction of fibres in the concrete mix led to a reduction in the workability and self-compacting characteristics. The early-stage characteristics of concrete were assessed using an environment chamber in a controlled environment. The fibre concrete was observed to influence the plastic shrinkage cracking. The restraining concrete ring tests confirmed the influence of the fibres on the strains exerted on the steel ring with varying percentage of fibres in the mix. The addition of fibres also influenced the concrete density, ultrasonic pulse velocity, compressive strength, flexural peak load and tensile splitting strength. The durability of feather-fibre concrete was assessed with reference to permeable porosity and permeability and chloride ion penetration. The inclusion of feathers as fibre reinforcement in concrete was found to have different effects on the fresh, early-stage and hardened properties of concrete, depending on fibre length and percentage volume fraction. However this research confirmed the potential of the exploitation of waste feather fibres as reinforcement in concrete supporting circularity in the agricultural and construction sectors.