8 Feb 2006
INDUSTRY RESEARCH PROJECT PAVES THE WAY FOR WIDER USE OF RECYCLED MATERIALS
New research, funded by WRAP (the Waste & Resources Action Programme) and supported by Tarmac, will test the performance of hydraulically bound materials (HBM) using recycled aggregates, for use in road construction.
These materials are relatively new to the UK and cover the use of recycled or primary aggregates bound together using slow cementing hydraulic binders that include materials derived from industrial by-products such as slag. They potentially provide alternative bound materials for use in road foundation and lower base layers.
The research will be outlined at the fifth international conference on the use of waste and secondary materials in pavement engineering, sponsored by Tarmac, to be held at Liverpool John Moore's University on 22nd and 23rd February 2006.
Designed to test the performance of HBMs in-situ, the research will involve comprehensive field and laboratory trials. The research is being managed as a collaborative effort by Tarmac, Scott Wilson Pavement Engineering and TRL and will be completed by March 2007. Dr Nizar Ghazireh, research manager at Tarmac, notes that the aim of this project is to relate the performance of these materials to the new foundation classes linked to the new HD26 specifications.
John Barritt, aggregates technical advisor at WRAP, will be speaking at the event. He comments:
"Since the Highways Agency included hydraulically bound mixtures in its specification for highway works for the first time in 2004, the highways industry has been busy developing recipes for sub-bases and bases, using recycled materials bound together using hydraulic binders including industrial by-products such as slag or pfa.
"However, to date, the industry has had only limited ability to predict and measure performance data on applications for HBM and this is holding back take-up of this potentially highly sustainable construction material.
The research we are now funding will address this, enabling client organisations and their designers to specify HBM more confidently across a wider range of applications. This research will help industry by encouraging the use of recycled and secondary aggregates and helping to conserve finite primary materials."
As part of the field trials, HBM will be used to provide a rigid sub-base and base layer for a heavily-trafficked quarry road at a Tarmac quarry in Essex.
Dr Howard Robinson, Tarmac's head of product development and chair of the forthcoming conference, comments:
"By testing the performance of HBM in-situ under heavy slow-moving traffic, we should be able to produce reliable independent performance data to enhance confidence and help to develop specifications for these materials. The adoptions of HBMs should be seen as a positive move by the highways sector in support of government policy aimed at developing a more sustainable construction industry.
"Of particular interest, we expect to be able to show that recycled and marginal quality materials can be used in the production of HBM. In doing so, this could help to elevate the use of recycled and secondary aggregates into higher specification materials."
John Barritt concludes:
"HBM is an exciting area of opportunity for the road surfacing industry, which will add value to secondary and recycled aggregates by extending their suitability for a wider range of applications."
The two-day conference is expected to attract more than 150 delegates representing a variety of industrial bodies and businesses worldwide.
For further information please contact Christine Smart, Rebecca Cowley, Delia Elcock or Louise Holt at Citigate Smarts on 0121 456 3199 or email: christine.smart@citigatesmarts.co.uk
