Concrete Retexturing Trialled On A30 In Cornwall To Reduce Road Noise

A section of the A30 in Cornwall has become one of the first locations in the UK to trial an advanced retexturing technique aimed at minimising road noise for drivers and nearby residents.

The National Highways project, carried out in partnership with Tarmac, Wirtgen and Atmo Technology, has reportedly achieved a noise reduction of up to 7dB.

This trial involves a single-pass process where grooves are meticulously introduced into the existing concrete pavement, while a grinding process enhances the surface texture. The combination of these methods is designed to decrease the contact area between vehicle tyres and the road surface, consequently reducing noise. The grooves further contribute to sound absorption.

In the UK, approximately 640km, or 4%, of the strategic road network consists of concrete roads, primarily constructed during the 1970s and 80s. Traditionally, concrete resurfacing has relied on diamond fine milling, a method that removes about 3mm of road material and has an expected lifespan of around five years per treatment. However, the new technique is reported to extend the operational lifespan of the road to between 10 to 15 years before requiring further intervention, promising significant cost savings over the lifecycle of the road.

The innovation operates without damaging the joints in the pavement, which is a notable advantage, as it decreases future maintenance expenses. This initiative forms part of Tarmac’s Next Generation Concrete Solutions (NGCS) portfolio.

The trial, which took place over a 1.5km section of the eastbound A30 near Penzance in March, involved testing five different surface profiles, each with unique groove dimensions and patterns. Atmo Technology utilised a mobile sound monitoring device to assess the noise levels generated by these profiles, all of which demonstrated a significant reduction in road noise.

A specialist Belgian company, Topoff, partnered with construction equipment supplier Wirtgen to develop a unique machine capable of performing the grind and groove processes in a single pass. This innovative equipment can resurface a width of 1.85m, increasing productivity by 150% compared to traditional methods, as it requires only two passes to cover an entire lane.

Moving forward, Tarmac intends to collaborate with National Highways to determine the optimal surface profile for future applications.

As this trial progresses, it may pave the way for broader adoption of this noise reduction technique across similar roads nationwide, potentially transforming the driving experience in urban and rural settings alike.

Tarmac regional contracting director Nick Angelou commented: “This significant trial has helped to develop a solution for concrete roads which can reduce noise for neighbouring communities as well as extend the lifecycle of the asset to deliver financial and environmental savings by eliminating the need for earlier intervention.”

National Highways National Concrete Roads Programme head Nick Knorr said: “This trial was part of our Concrete Roads Programme which will ultimately replace all of our existing legacy concrete roads. Achieving this goal will take time and significant investment, so it is essential that we find cost effective ways of extending the life of those still in use until they can be replaced.

“NGCS is a promising technique and we have seen positive results related to noise reduction and ride quality. Ongoing monitoring and future trials will confirm its full impact on asset life extension, but the initial observations are encouraging.”

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