Contractors World


The UK and Ireland's only FREE to READ digital publication for construction, demolition, mining and quarrying industries

Contractors World UK & Ireland
2012 Vol 2 No 6   
Forward: Print Page Register (free) Bookmark Page

cw cw cw cw cw Buyers Guide cw cw cw

contractors world magazines on facebookContractors World magazines onTwitter
Facebook Twitter

Contractors World UK
Read more news in the
Contractors World
International


BREAKING NEWS

 

SEE MORE


LIBRARIES

• back issues
•  brochures
• 
videos


Contractors World - Eco Friendly publishing
Sponsor a tree
by planting
your logo
in our
virtual forest
to aid the

Lighthouse Club
Benevolent Fund

previous page   PAGE 18 of 38    next page

New asphalt mix using recycled tyres promises significant all round benefits - page 2 of 4

Recycled rubber with white polymer pellets.Laboratory Design

Following a study visit to Germany, Breedon carried out extensive tests on the modifier in its central laboratory and then set out to design a thin surfacing asphalt appropriate for Britain’s roads.

Recycled rubber with white polymer pellets.

The Road+ additive forms part of the binding agent, along with bitumen in the asphalt. This is achieved by the double bonds of the polyoctenamer in Road+ reacting with the sulphur on the surface of the rubber and the maltenes and asphaltenes in the bitumen.

Cross-linkage between the bitumen and rubber therefore takes place without the need for the rubber to be melted. This allows the production temperature to be kept below 170º C, yielding obvious environmental benefits.

Different proportions of the additive can be added depending on the level of performance modification required and, as increasing amounts are added, the binder moves from being a thermoplastic to a thermoset material. The laboratory design work identified the optimum blend of Road+ with bitumen to give the correct volumetrics to ensure durability, rut resistance and high surface texture in the final material.

Plant and surfacing trials were then carried out in Breedon’s Benninghoven asphalt plants in its quarries at Clatchard and Ethiebeaton in Scotland, to check the functionality of the material and ensure that the designs were achieving the demanding performance criteria required.

As with standard asphalt, the aggregate in the mix is first dried and heated to around 165º C and then blended in a mixer. Typically, around two tonnes is batched at a time. The Road + is then added in low-melt bags which instantly disintegrate, allowing the Road+ to disperse into the blended aggregate. The final part of the mix, the bitumen, is added last. The total mix time for all these ingredients is typically around one minute, depending on the efficiency of the mixer.

The finished product is transferred to large insulated “hot bins” for storage prior to dispatch. The key production difference between this material and normal asphalt is that, at this point, it must be left for around one hour to allow the chemical cross-linking to occur, although part of this hour can be used to transport the material to site for laying. Production and laying of this material can be done with standard kit without any major issues. The mixing system can be fully automated, although this was unnecessary for the initial trials.

Breedon doing trials of new skid resistance measuring device on a trial strip at the batching plant.Trials with Transport Scotland

The plant trials were conducted with the close involvement of Transport Scotland, which subsequently decided that the material warranted the formation of a Transport Scotland Pavement Forum subcommittee to develop a standard specification for this type of material.

Breedon doing trials of new skid resistance measuring device on a trial strip at the batching plant.

Following the preliminary plant and laying trials, Breedon concluded that a very high performance thin-surfacing material incorporating the new rubber modifier could be produced in volume, that will bring significant installation and performance benefits on Britain’s roads. A Technical Submission was therefore made to Transport Scotland through Breedon’s associate company, BEAR Scotland (which manages a sizeable proportion of Scotland’s trunk road network) for a formal trunk road trial of the new material.

Following Transport Scotland’s approval for the trial to go ahead, a short stretch of the A90 dual carriageway between Perth and Dundee was resurfaced with the revolutionary material in May 2012. This stretch of road is one of the busiest in Scotland, carrying around 35,000 vehicles a day.

page 3 of 4 >>>

 

Tweet this page


 

 

 

previous page   PAGE 18 of 38   next page

 
red divide
CW Contractors World - the digital publication for construction industry

Contractors World Magazines are published by VVV Limited
©VVV Ltd 2012 All Rights Reserved

Publisher: Roger Lindley
Content compiled and edited by:
Roger Lindley MCIM

Page updated: August 2012

 

READ OUR OTHER MAGAZINES

Contractors World -International
Contractors World International up-to-date information on news, plant and equipment from around the world.

CLICK HERE


Contractros World - Australia
Australia News


cmldir.com
Online Buyers Guide of Construction, Quarrying

Contractors World - Eco Friendly publishingBy reading this page on line you are helping to save trees.
Trees saved up to August 2012 > 814
See our virtual forest


The monthly magazine Contractors World - UK & Ireland is proud to promote and support the Lighthouse Club Please give generously. Contractors World Support the Lighthouse Club


CONTRACTORS WORLD MAGAZINES
CML House
7 Bell Mead
Sawbridgeworth
Herts CM21 9ES
UK
Tel: +44 1279 600598
Email: infodesk@cwmags.com
URL: http://www.cwmags.com

Contractors World is many publications in one - construction news for latest information (read our daily news pages) and a site equipment magazine featuring site reports from around the world and reviews of construction plant and equipment as it is introduced.

Written specifically for earthmovers, quarry managers, plant hire executives, and others with an interest in the construction and related industries. Contractors World are today, the world leading e-magazines for the construction industry - redefiining publishing for the digital age

Registered Office: 54 Sun Street, Waltham Abbey, Essex EN9 1EJ, UK
Registered as a company in England and Wales, number 3892263

Contractors World and Contractors World - UK & Ireland Edition are independent publications published for CWMAGS Limited by VVV Ltd.

The mention of companies and/or products within the editorial pages or in advertisements does not infer any endorsement by the publisher or editors. All editorial is freely given, without conditions and at the sole discretion of the editor. Opinions expressed by contributors are not necessarily those of the publishers. Other than saving and distributing in complete page formats, copying, reproduction, decoding or disassembly of content or computer code by any means of any part of the publication is prohibited unless prior approval is provided by CWMAGS Ltd in writing and confirmation received of agreement with any terms and conditions applicable. PDF version may be downloaded for personal use but no content may be used for promotional purposes or copied to web sites. All images and video content are subject to copyrights.