Composites obtained by recycling carbon fibre/epoxy composite wastes in building materials

Wastes made of thermosets pre-preg scraps deriving from the production of epoxy-carbon fibres composites have been recycled without any previous high temperature or chemical treatments as reinforcement to produce building materials. Short chopped fibres coated by the resin (5–8 mm length) have been added up to about 5% volume content to different types of matrix, one based on conventional Portland cement and two based on geopolymers, deriving either from metakaolin or from fly ashes. In the last case, the derived materials are almost completely made of recycled ingredients. The workability, microstructure, porosity, physical and mechanical properties of the derived materials have been investigated. Superior flexural strength and increased toughness have been obtained. The reinforcing effect of the recycled waste is particularly interesting on the properties of the ambient cured fly ashes geopolymers and can promote the use of these matrix. This is an attempt to produce building materials with improved properties at the same time solving waste disposal problems.