Abstract
Recycled tyre steel fibre (RTSF) is considered as a potential and sustainable alternative to manufactured steel fibre (MSF), while RTSF resulted in lower energy absorption capacity and more serious corrosion problem in concrete compared to MSF. This paper presents an experimental study on engineering properties of concrete reinforced with hybrid RTSF (0.5%–0.9% Vf) and polypropylene fibre (PPF, 0.1%–0.5% Vf). Results show that combining RTSF with PPF could compensate the serious workability loss caused by RTSF and the workability was improved by 38.9%–66.7%. However, the compressive, splitting tensile and flexural strengths were weakened significantly when PPF was over 0.3% Vf in hybrid fibre reinforcement (total content of 1.0% Vf). The strain field shown in digital image correlation images suggests that hybrid RTSF and PPF can create a synergistic effect in restraining the crack growth and the post-cracking behaviour of concrete especially toughness that was enhanced with the presence of PPF. RTSF was more effective in restraining shrinkage of concrete than PPF. With the increase of PPF content in hybrid fibre reinforcement, the chloride migration coefficient of concrete was reduced by 4.9%–6.8% as compared with the mixture reinforced with only RTSF.
Highlights
Given the fact that normal concrete is inherently brittle making it unsuitable for certain applications, e.g. structural elements subjected to potential dynamic loadings, fibre reinforced concrete (FRC) incorporating randomly distributed short fibres such as steel, polypropylene and glass fibres is introduced to mitigate the brittleness and potential cracking problem of conventional concrete
The workability of FRC can be affected by the critical fibre content, while this value varies between different fibres (Ranjbar and Zhang, 2020)
Further replacement of recycled tyre steel fibre (RTSF) by polypropylene fibre (PPF) weakened the positive influence in workability
Summary
Given the fact that normal concrete is inherently brittle making it unsuitable for certain applications, e.g. structural elements subjected to potential dynamic loadings, fibre reinforced concrete (FRC) incorporating randomly distributed short fibres such as steel, polypropylene and glass fibres is introduced to mitigate the brittleness and potential cracking problem of conventional concrete. Many studies (Aiello et al, 2009; Centonze et al, 2012; Fraza~o et al, 2019; Grzymski et al, 2019; Leone et al, 2018; Skarz_ ynski and Suchorzewski, 2018; Zamanzadeh et al, 2015) examined the effect of recycled tyre steel fibre (RTSF) content on the physical, mechanical and durability properties of FRC with a primary aim of seeking whether the manufactured steel fibre (MSF) could be replaced by RTSF. Rapid chloride migration (RCM) test was conducted to estimate the effect of different hybrid fibre reinforcements on the durability-related performance of concrete
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call