The road to excellence

How surface dressing quality standards can help highways authorities deliver improved asset management.
By Howard Cooke

There’s no doubt that the recent announcement of £1.2 billion to fund road improvements, cut congestion and improve journey times is excellent news. However, it’s important that we as an industry understand this is in the context of a growing emphasis on sound asset management in the road system.

“It is vitally important that we achieve maximum returns from the money which has been allocated for highways maintenance,” Robert Goodwill, Parliamentary Under-Secretary of State for Transport,” declared in Gearing up for efficient highway delivery and funding, the key 2014 consultation document that addresses how £5.8 billion funding for local highways maintenance up to the year 2021 will be distributed.

A £580 million incentive fund has been put in place to “reward those authorities that can demonstrate that they are repairing their roads efficiently and carrying out cost-effective improvements in line with the recommendations of the DfT-backed Highways Maintenance Efficiency Programme (HMEP)”, the NCE announced in January 2015. Similarly, Mathew Lugg from HMEP had this to say: “The ability to produce evidence of good asset management will be key to securing more of the pot.”

Surface dressing

One effective way of demonstrating good asset management is to extend pavement life with surface dressing; in fact, it can offer an ideal solution when used at the right time and in the correct way. Surface dressing can extend the life of the carriageway for some 10–15 years: 10 years for those roads with medium-to-high traffic and up to 15 years for roads with low-to-medium traffic, according to the Road Surface Treatments Association (RSTA)/ADEPT).

However, it is important to note that surface dressing customers such as local authority engineers are now increasingly focusing on relatively recently introduced mandatory regulations designed to boost quality standards across the industry as part of their focus on maintaining their asset base.

Surface dressing treatments are regulated by harmonised Product Standard (hEN) BS EN 12271. Since 1 July 2013, contractors undertaking end-performance contracts to MCHW [6} clause 922 (Surface Dressing) have needed to obtain a CE mark for their product’s legal requirement. That said, although CE marking was a legal requirement from 1 July 2013, it was not in practice being asked for when Dr Howard Robinson reviewed the regulations in the Institute of Asphalt Technology’s IAT Yearbook back in 2014. At the time he predicted that it would probably take “another couple of years “ before highways authorities collectively started to consistently demand CE accreditation from the supply chain.

Asphalt Surface Dressing Process


De-risking the process

Fast forward to today and the situation has moved on significantly, with highways authorities increasingly asking for evidence of CE accreditation. This has clear benefits for customers in terms of their professionalism and ensuring that contractors are able to design, build and guarantee their work. Importantly, under the new system, customers can have far more confidence in the quality of work undertaken by suppliers, which will be designed by practitioners, built to their specification and guaranteed.

Under the new rules, companies like Asphalt Reinforcement Services have taken on the design component of the project as well as the build, effectively making us responsible for ensuring that the entire process runs smoothly and is fit for purpose. This transfers the risk from the customer to the contractor. Additionally, companies may also offer extended warranties to provide clients with additional confidence in their work. All of these initiatives are raising standards in the industry.

Accreditation process

CE-marked products come with a Declaration of Performance based on a one-year TAIT (Type Approval Installation Trial). The process is quite time-consuming and onerous because organisations have to certify every product and each type of environment that they operate in.

Contractors must complete their one-year TAITs and operate a quality management system to BS EN ISO 9001, in order to obtain a CE mark and DoP (Declaration of Performance). In addition, they must have their Factory Production Control (FPC) system successfully audited against the requirements of the relevant hEN by a Notified Body (NB) accredited by UKAS or equivalent body.

What’s more, a TAIT is required for each type of surface dressing – such as single, racked-in and double dressing – and for different road types. Consequently, Asphalt Reinforcement Services has been through the process for the different types of surface dressing for a wide range of different road categories.

While the largest, high-productivity contractors have dealt well with the accreditation process, many smaller contractors have not found it such smooth going. “Large national contractors seem to have coped fairly well and speedily with obtaining their CE marks; however, it appears that smaller to medium-sized contractors required more help and assistance from the RSTA and their certification bodies,” Dr Robinson wrote in 2014. “It will take some time for CE marking to become embedded and become the norm,” he added.

Since then, however, specifiers have increasingly been insisting on CE accreditation as they move away from the old Clause 919 contract system. “The public procurement directive says public bodies should give priority to purchasing products that have a CE mark,” Dr Robinson points out. Consequently, those contractors not able to meet the new regulations are finding their options increasingly limited.

In general, organisations seeking to work on national highways need to undergo a highly rigorous accreditation process as part of the National Highways Sector Schemes, according to the UK government regulations dealing with motorways and major road. These are bespoke quality management systems for organisations working on the UK road network, and are based on the ISO9001:2008 standards, although they do not duplicate them.

Companies supplying services to Highways England under the Specification for Highways Works (SHW) must be certified under all the relevant schemes for the work they are carrying out. “These schemes aim to make sure that work is carried out to the highest standards of professionalism, using properly trained staff, while also placing a strong emphasis on health and safety.”

Although Asphalt Reinforcement Services is by no means one of the largest contractors we consider it to be important that we are also certified to the same standard as organisations that are significantly larger: we are proud of our NHSS13 compliance, CE mark, ISO 9001 quality compliance, and an NVQ-qualified workforce. This enables us to stand out among a pool of smaller contractors.


At Asphalt Reinforcement Services we’re seeking to keep ahead of the curve by bringing in new technology and equipment. This has proved to be a major benefit for the company, and we are now able to bid for surface dressing contracts to Clause 922 highway works as well as cycle tracks, footways and heritage work.

A good example of this innovation is our ability to further enhance carriageway life by using a non-woven geosynthetic interlayer. This is laid on the road surface ahead of the surface dressing process and forms a retention and regulating layer for the bitumen so that the chip can be embedded with good adhesion.

The use of paving fabrics can extend the life of surface dressing by an additional 50 to 75% in warmer climates, which we are starting to experience in the UK. There are a number of additional benefits such as suppressing reflection cracks (the SAMI effect); this system also helps to prevent bleeding and contributes to providing an impermeable layer, so protecting the lower pavement.

Asphalt Reinforcement Services uniquely has the expertise to offer a fully integrated service by installing both this paving fabric interlayer and the surface dressing.

Minimising inconvenience to the public

We also recognise that surface dressing can be a real inconvenience to motorists and residents, and we aim to put their needs first. We train our staff to recognise the importance of making sure members of the public are respected. For instance, when we’re working within housing estates we can offer a very personal service in terms of the way we deal with members of the public. This approach seems to be working well for us.

A recent project at the Silverstone grand prix circuit is a good example of our approach. Although the resurfacing was due to take place over the weekend – which in itself was a tight schedule – the work was rained off on the Saturday. Consequently, we raced through the work on the Sunday to complete it on time for the event, and received numerous plaudits for the quality of the job delivered. Quality standards are the key to success in this industry.

Howard Cooke is managing director of Asphalt Reinforcement Services and the incoming chairman of the Road Surface Treatments Association.