Driving up quality for recycled tyres
Recent guidance means local authorities and their contractors can now procure quality assured tyre-derived rubber material for a variety of uses. Jacks Guinness explains
While this material boasts many excellent properties and offers a cost-neutral and environmentally-friendly alternative to many primary materials, some local authorities may be nervous about procuring a material that historically has lacked any guidance or quality standards.
However two documents have now been developed in collaboration with the BSI to provide manufacturers of used tyre materials with guidance to ensure their finished materials are industry standardised and quality assured. For buyers of material, this means that the materials they are procuring meet an industry-recognised specification and are environmentally sound.
The PAS 107 and 108 documents from the waste & resources action programme (WRAP) offer local authorities the quality assurance and security to encourage and promote the use and procurement of tyre-derived rubber. The use of tyre-derived material has benefits both in its application and for the companies procuring it. It is lightweight, impact resistant, lacks any odour, and is durable and non-toxic.
By increasing the use of this material within their community projects, councils are able to use materials with a high recycled content. This will not only help them to increase the percentage of recycled content used, but also lead the local community as a champion of waste and recycling.
The WRAP documents relate to different end-user applications, with both having a wide scope of use for community projects. PAS 107 outlines specifications for manufacturers to produce grades of size-reduced tyre rubber such as rubber crumb and shred while PAS 108 outlines guidelines for the specific density, porosity and dimensions of tyre bales.
A question of character
The PAS 107 voluntary guidelines will ensure that manufacturers using them will produce only the highest quality tyre-derived rubber, characterised by category, material source, processing technology, particle size and its physical properties. This characterisation will make it straightforward for procurers to clearly identify the different forms and properties of the material, allowing easy comparison to their primary material equivalent.
The potential uses of tyre shred and crumb are diverse. They include walkways, safe play areas, sports and leisure grounds, paving, porous piping, natural and coloured mulches, drainage infill, and as an aggregate replacement.
The PAS 108 document outlines guidelines for the specific density, porosity and dimensions of tyre bales. With unique engineering properties, tyre bales can be used in a range of civil-engineering and construction applications such as road foundations, embankment fill, slope stabilisation and drainage systems. Tyre bales provide a cost-effective and useful system to use on larger projects such as highways due to their light weight, permeability and low bulk density.
The PAS 107/ 108 documents are available in the form of a PDF download summary sheet from www.wrap.org.uk/construction/tyres
Jacks Guinness is marketing project manager for tyres at WRAP