Evaluation of recycled tyre steel fibres adhesion to cement matrix

• Published in: Journal of Building Engineering 2023-06, Vol.68, p.106146, Article 106146
• Main Authors: Michalik, Agnieszka, Chyliński, Filip, Piekarczuk, Artur, Pichór, Waldemar
• Format: Article
• Language: English
• Subjects: Adhesion; Carbon footprint; Fracture toughness indices I5 I10 I20; Manufactured Steel Fibres (MSF); Recycled tyre Steel Fibres (RTSF); Work of fracture
• ISSN: 2352-7102; 2352-7102
• DOI: 10.1016/j.jobe.2023.106146

The production of Manufactured Steel Fibres (MSF) dramatically contributes to the natural environment's pollution by releasing significant amounts of carbon dioxide. The acquisition of new solutions of dispersed concrete reinforcement should have three simultaneous directions: environmental, economical and practical, which means a function of reinforcing brittle cement matrix. This paper presents the results of comparative studies on concrete with MSF and concrete containing the same amount of (purified) Recycled Tyre Steel Fibres (RTSF). The adhesion of fibres to cement matrix and their dimensions are the feature that determines the effectiveness of dispersed reinforcement in concrete. In order to evaluate the adhesion of steel fibres to the cement matrix, the pull-out tests were carried out for RTSF and MSF wires. The work of fracture and fracture toughness indices for fibres of different shapes and diameters were determined as the measure of adhesion. Adhesion was also evaluated in microscopic observations of the fibre-cement interfacial transition zone. The test results indicate that RTSF adheres to cement matrix much better than MSF. The fracture and fracture toughness indices of RTSF are at the same level as for hooked-end MSF but lower than in the wave-cut and hooked-end MSF. A microscopic analysis additionally confirms the excellent adhesion of RTSF to the cement matrix. The application of waste RTSF reinforces the concrete structure and helps save natural solutions, following the sustainable construction development policy. •Recycled tyre steel fibres have much higher adhesion to cement matrix than industrial steel fibres.•Good adhesion of tire fibres contributes to the good effectiveness of concrete reinforcement.•Properties of concretes with recycled tyre fibres are equivalent to those of concretes with industrial fibers.•Use of purified recycled tyre fibres is a good alternative to the high-emission production of steel fibre.