Enews - Issue 2 - Autumn 2010

Clients’ Viewpoint

Rod Chaplin, Highways Agency

The Highways Agency has a huge road network and one that is pounded by a major section of the nation’s lorries and cars every day. Tough targets are imposed, including improving safety and journey time and minimising environmental impact. All have to be met but are also subject to a tightening of the purse strings. Part of the reaction to meeting these pressures has been the creation of the ‘Managing Down Costs’ Toolkit.

The MDC Toolkit (see aims to assist a change of culture of client, designers, specifiers and contractors by offering a range of cost saving ideas, processes and materials that they may not be familiar with. It is designed to encourage exploration of options beyond the obvious and traditional ways and means for meeting the client’s technical, legislative and environmental requirements. The Toolkit will provide a progressively wider range of ideas for reducing the costs of construction and, equally importantly, the costs of management of that asset.

Whilst adopting any individual idea is not compulsory, all HA major project teams must demonstrate stage-by-stage, from inception to opening, that they have fully considered the options in the Toolkit. The appropriate and successful use of any idea, material or product type from the Toolkit will be recorded together with any new ideas used, which will add to the knowledge and experience of HA staff, its contractors and suppliers. It is to be hoped that by using the Toolkit, designers and suppliers will continue to develop and feed back ideas that are effective, long lasting, sustainable and reduce costs, so that these can be added to the Toolkit for all to see and consider.

The RSTA is working closely with the Highways Agency to provide up to date information on the full range of surface treatment options now available with associated benefits for inclusion in the MDC Toolkit.

Steve Betteridge
Principal Materials Engineer, Development Services, Lincolnshire County Council
Secretary, ADEPT Soils and Materials, Design and Specification Group

Many Local Authorities are already responding to changing financial circumstances. They are not only preparing for the anticipated reductions in funding in this Autumn’s Comprehensive Spending Review, but a number have also reduced some of their spending for this financial year. This is particularly so for departments with Highway Authority responsibilities.

These reductions are resulting in reviews of the maintenance techniques and processes deployed by Highway Authorities. Even greater emphasis is being placed on achieving optimum service life of the road pavement structure by best use of available resources, including carbon.

Various surface treatments provide increasingly vital techniques in assisting highway maintenance managers in preserving and improving elements of the highway.
Many Highway Authorities have, for example, very successfully and significantly extended the service lives of distressed thin surface courses by the timely application of appropriate surface dressing. There can be some difficulties associated with deploying this technique if the thin surfacing was originally installed for noise reduction reasons but otherwise an appropriate surface dressing is frequently the preferred maintenance intervention for these materials.

For urban locations a micro asphalt can be the preferred alternative to surface dressing. Public tolerance of micro asphalt is generally greater than that for surface dressing, particularly in the residential environment. Improvements in micro asphalts ability to retain texture depth, and hence increase its effective life, is assisting in increasing the use of this family of products.

It is the case that carriageway structural maintenance will become more targeted and a proportional increase in patching, rather than more comprehensive inlay or reconstruction can be expected. For rural roads, including major roads, surface dressing is increasingly likely to be the selected surface treatment. The industry is advised to be prepared for this possibility, particularly with regard to an adequacy of supply of chippings of required PSV and quality.

Recent campaigns have highlighted the success of a particular UK enterprise - that of pot hole propagation. Highway maintenance managers are very mindful of the undesirable results of this and acknowledge the approach of Highway Authorities to pothole treatment can be wanting. ADEPT research into the mechanisms of pothole development is in the process of being published. The application of the results of this research together with the techniques and treatments available from RSTA members will be needed to combat and treat this increasing problem.

The difficulties faced by Highway Authorities in maintaining the highway network will become even more testing in the foreseeable future. The services provided by the RSTA and its members will be an essential part of maintaining the network.

Dave Rigby, Lancashire County Council

The last winter that we experienced was probably the worst on record for frost attack on carriageways. The result is that wherever you travel you do not see a single carriageway without some form of attack, unless of course your client is prudent enough to have a logical surface dressing programme.

It is a well known fact, indeed one that is widely publicised, that surface dressing acts as a waterproofing agent against the ingress of water into the pavement. Good patching for structural maintenance together with a well-designed dressing will add at least 5 years performance and in some case more to the pavement life.

Fractures and fissures in the carriageway surface should be identified early before the freeze/thaw scenario takes hold, leading to the breakdown of the bitumen bond. Once pockets have formed in the carriageway surface, the constant traffic causes a pressure wave into the material by the pressing of water causing continual disintegration.

Carrying out surface dressing of the carriageways and filling the fissures with bitumen emulsion means that there is nowhere for the water to hide thus taking away the pressure wave caused by the motor traffic.

Our opinion in Lancashire is that surface dressing is the best and most cost efficient way of preventing the freeze/thaw situation on carriageways. This is proven when travelling on roads in Lancashire those roads that have been surface dressed within the last 5 years and in some cases 7 years are virtually pot hole free. There are, however, some exceptions where utility services have carried work and so broken the waterproofing.

If budgets allowed, I am sure that all Unclassified and ‘C’ carriageways would be surface dressed in Lancashire, especially in rural areas and the incidence of pot holes would be reduced even further. This leaves us with another fact: Surface dressing means.... reduction in the number of pot holes.... FACT.

Steve Hunt, Project Manager, British Board of Agrement

Since the launch of HAPAS in the late 90s the BBA have continued to work closely with industry in developing and improving the scheme. The most recent revisions have focused on the Approved Installer scheme and highlighting the need for nationally recognised qualifications for competency

Through the scheme’s appointed Specialist Group (SG1), the BBA has identified and implemented improvements to the High Friction Installer Scheme within the following areas:

  • health and safety
  • competency of installers
  • routine surveillance
  • generic approach to approval.

A key update has seen the inclusion of minimum competency requirements for installers. Until recently, the competency of installers under the HAPAS Installer scheme was confirmed via the pre-approval process. Competency was confirmed initially by the manufacturer and then through third party inspection by the BBA. The revised scheme now highlights the need for installers to hold nationally recognised qualifications specific to high friction installation.

The BBA are keen to highlight the importance of competency and training to ensure HAPAS approved systems and products are installed in accordance with Certificate holder’s requirements and recently assisted the RSTA with a HFS Training Seminar, which identified the key changes to the scheme.

The involvement of industry in the development of the scheme will result in HAPAS continuing to respond to the needs of those specifying, manufacturing and installing HAPAS approved products. The greater assurance through the improvements to the pre-approval process for installer competency will provide improved specifier confidence within the high friction surfacing Sector and greater value in Certification to the installers and the manufacturers.

Further information on Approved Installers for High Friction Surfaces regarding the Installer Guideline for High-friction Surfacing Systems can be found on the BBA website under HAPAS Product Sectors:

ABG   Asphalt   ASI    Colas   Eurovia   Jobling   Keily Bros.
Klaruw Systems   Nynas    Prismo   Tencate   Total   Tensar   Velocity