Exploitation of biomaterials in construction : keratin feather fibres in cement-based materials

Abstract

Utilising chicken feathers in concrete materials has been attracting the attention of researchers due to the environmental benefits of reducing waste from the poultry industry, where large volumes of waste are generated with every slaughter. Local poultry processors produce over 7×104 metric tonnes of waste each month, and the keratin rich feather fibres, together with other waste, are incinerated at a waste processing plant. The process of extracting fibres was studied from start to finish, where the fibre would have been disposed of as a by-product of poultry for food consumption. 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. An experimental investigation assessed the fresh properties of concrete with added fibres, focusing on workability, self-compacting characteristics, and rheology, with note that fibre incorporation reduced workability and self-compacting properties. Early-stage characteristics were examined in a controlled environment, revealing that fibres delayed and narrowed plastic shrinkage cracks. Restraining concrete ring tests and Kraai mortar test panels showed that fibre-reinforced specimens did not crack during the test. Fibres also affected the concrete's density and ultrasonic pulse velocity, and improved the compressive strength, ductility, and tensile splitting strength. However, the inclusion of fibres negatively affected the overall flexural strength and toughness. Improvements in durability were evaluated through vacuum saturation porosity and chloride ion penetration testing. Therefore, this research confirmed the potential for the exploitation of waste feather fibres as reinforcement in concrete, supporting circularity in the agricultural and construction sectors.