Energy-efficient concrete could reduce road closures

The road type, made of dry-mix concrete reinforced with recycled steel fibres from waste tyres, is 12 per cent cheaper than conventional road construction and its construction time is 15 per cent less. In addition, over the lifetime of the concrete pavement, there is a 40 per cent reduction in energy consumption.

Each year in the EU, 3.2m tons of tyres are produced annually − all of which have to be recycled. However, 15-25 per cent of the tyre is comprised of steel fibres, which hold a lot of rubber and plastic from the reinforcement, limiting the options for reuse in new steel production


The new fibre-reinforced concrete, developed by the team at Sheffield and their EU partners as part of the Ecolanes FP6 project, is able to use processed steel fibres for the first time. These steel fibres from post-consumer tyres are at least 50 per cent cheaper than manufactured steel fibre reinforcement and using the fibres from waste tyres means there is no need for raw material to be mined and formed, which would require extra energy.

An additional benefit of the concrete is that it uses a very different consolidation method, called roller-compaction, and therefore the dry mix requires less cement than conventional concrete and is stable enough for light traffic straight after being laid. Conventional concrete normally requires between seven and 28 days before traffic can be allowed on. This is something that could significantly reduce road closure times and traffic build-ups after a new road has been laid.



The concrete, which was developed for the project as part of a bid to create long-lasting rigid pavements for the transport industry, was then tested for its durability. The team kept the material within a climate chamber for 56 days, with a daily changing temperature from 20 to -20°C.