Use of recycled textile fibres for sustainable and thermal insulating Fibre Reinforced Cement

Recycling and sustainability are hot topics for Civil applications. Since 37.4% of Italian non-hazardous waste comes from the textile field, many studies focused on their reuse. This work investigates the recovery of waste textile microfibres, deriving from finishing of fabrics, into sustainable and low conductive Fibre-Reinforced Cement (FRC). The microfibres are characterized through FTIR technique and Scanning Electron Microscopy; moreover, water content and water absorption are evaluated for mix design. Unsaturated, saturated and NaOH treated microfibres are considered. Following a preliminary workability evaluation, they are introduced in Portland cement in 1%, 2%, 3%, 4% by weight. At increasing fibre percentage, the three-point bending test displays an enhance from 1.5 to 4 times the maximum bending load of non-reinforced Portland and a marked increase in toughness is observed. The linear shrinkage is reduced from 20% to 80%, and NaOH microfibres result in more efficiency. Stereomicroscopy confirmed a high fibre dispersion into the cement matrix. A reduction in thermal conductivity is observed when increasing percentage of the untreated fibres, and for 4% fibre percentage the Portland insulation power is doubled. The feasibility of using recycled textile microfibre into FRC is demonstrated and results in improving sustainability, mechanical properties and power insulating.