Nestled in the heart of London, Spur Road (SW1A) serves as a vital artery within the prestigious Royal Parks. Maintaining the impeccable condition of its infrastructure is paramount, reflecting the grandeur and heritage of its surroundings. When the time came for essential resurfacing, the project demanded a solution that balanced durability, aesthetic sensitivity, and efficient execution within this Royal iconic setting. The initial consideration for the resurfacing involved selecting materials that would not only withstand the rigours of traffic but also complement the visual character of the Royal Parks to preserve heritage using modern solutions. While specific material preferences existed, GW Highways, in collaboration with suppliers, sought a solution that honoured the aesthetic intent while ensuring optimal long-term performance and resilience.
The chosen approach involved the application of high-quality Red Hot Rolled Asphalt, known for its longevity and robust performance to ensure a harmonious blend of functionality and appearance. For the crucial chipping layer, a high-performance British granite with a natural pinkish-red hue and a high Polished Stone Value (PSV) of 60, ensuring excellent skid resistance, was selected. To gracefully meet the visual expectation for a consistent renditioned surface, these chippings were treated with a premium red coating that has a proven history of successful application within Royal Parks projects. This thoughtful selection ensured a harmonious blend of safety, durability, and the desired visual appeal. The resurfacing works were meticulously planned and executed to minimise any impact on this significant location. GW Highways’ experienced team carefully planed the existing surface, applied a bonding coat, laid the new asphalt, and precisely applied the coated pinkish-red British granite chippings. This efficient approach ensured a high-quality finish with minimal disruption to the surroundings.
Following the project’s completion, a site visit by GW Highways’ Technical and Contracts Directors provided valuable insights. Comparisons with previous resurfacing works within the Royal Parks revealed the long-standing success of materials similar to those used on Spur Road, demonstrating excellent colour retention and overall durability. This observation instilled confidence in the longevity and performance of the newly laid surface, ensuring it will continue to serve this prestigious location well into the future. The successful resurfacing of Spur Road stands as a testament to GW Highways’ commitment to delivering high quality infrastructure solutions in even the most sensitive and prestigious environments. By carefully considering both performance and aesthetic requirements, and through meticulous execution, the project enhances a Royal icon, contributing to its lasting legacy for all who visit and pass through. GW Highways is proud to partner with The Royal Parks in maintaining the splendour and functionality of their exceptional spaces.
Sea Street in Whitstable serves as a vital link for both local traffic and businesses, yet years of wear and tear had taken their toll. The ageing concrete slabs had deteriorated significantly, leading to widespread surface defects, reduced service life, and increased maintenance demands. Recognising the urgent need for a long-term solution, Kent County Council engaged GW Highways Ltd (GWH) to assess the road’s condition and deliver a sustainable, high-quality refurbishment.
To ensure a thorough understanding of the road’s challenges, GWH conducted an in-depth site investigation. This included: Identifying critical failures in the deteriorating concrete slabs, such as extensive cracking, settlement, and material degradation. Conducting precise measurements to determine the varying thicknesses of the existing concrete slabs and overlaid materials. Performing a comprehensive evaluation of the subbase, analysing its health and structural integrity to determine the most effective approach for reconstruction.
Designing a New Flexible Construction
Following the investigation, GWH engineers devised an optimised flexible pavement solution to replace the failing rigid slab structure. This bespoke design aimed to: Improve load distribution and adaptability to traffic-induced stresses, reducing the risk of future cracking. Enhance durability against thermal expansion and contraction, a key factor in maintaining long-term road performance. Integrate seamlessly with existing drainage infrastructure to prevent water ingress and the associated structural weaknesses it can cause.
Execution and Implementation
A meticulous execution plan was developed to ensure efficiency and minimal disruption: Precision planning techniques were utilised to systematically remove the old concrete slabs, minimising waste and ensuring as smooth transition. Proof rolling of the exposed subbase was conducted to identify and address any weak points, reinforcing the foundation where necessary. A high-quality flexible pavement structure was installed using industry best practices, incorporating robust materials to enhance durability and extend the road’s service life.
The transformation of Sea Street has delivered remarkable benefits. The newly implemented flexible pavement structure offers significantly improved ride quality, reduced long-term maintenance costs, and enhanced resilience to traffic loads. The strategic planning and expert execution by GWH have resulted in a road that not only meets but exceeds performance expectations, ensuring Sea Street remains a dependable and well-maintained route for the Whitstable community for years to come.
The A299 Thanet Way, a crucial route in Whitstable, required significant reconstruction due to the challenging soil conditions in the area. The clay exhibited severe shrink-swell behaviour, leading to considerable seasonal volume changes and instability, which threatened the road’s long-term durability.
Initially designed with a total thickness of 1.3 metres, the project required a more efficient solution to address the problematic soil while optimising costs. GW Highways collaborated with industry experts to develop a revised design that reduced the required depth through advanced mechanical stabilisation techniques. This new approach employed recycled materials and used innovative technology to enhance performance and sustainability.
The revised design incorporated the use of two types of geogrids, each strategically placed within different layers of the road structure. One geogrid was used within the capping layer, and the other within the subbase layer. These geogrids were selected to ensure that their aperture sizes matched the aggregate sizes in their respective layers, thereby enhancing mechanical interlock and improving load distribution. This strategic integration allowed for a significant reduction in the overall reconstruction thickness, decreasing it from 1.3 metres to just over 0.6 metres. In addition to the geogrid use, the project embraced sustainability by recycling 50% of the asphalt base and binder materials. The removed surface course was also recycled and reintroduced into the new surface course, further enhancing the project’s sustainability and minimising waste.
Rigorous testing was a cornerstone of the project to ensure structural integrity and performance and provide quality assurance. Continuous testing of the subgrade, capping, and subbase was conducted to verify that they met the necessary load-bearing requirements before the asphalt overlay was applied. This thorough quality control was crucial for ensuring the road’s long-term durability. All materials for the project were sourced locally from Kent, supporting GW Highways’ commitment to localism and reducing transportation related environmental impacts. Meticulous planning ensured that materials were available up front, contributing to an accelerated construction timeline and an eight-week reduction in the overall project duration. The project also focused on local economic benefits by employing local supply chains throughout. This approach not only supported the local workforce but also contributed to the regional economy by keeping project expenditure within the community.
The A299 Thanet Way reconstruction project demonstrates GW Highways’ expertise in addressing complex engineering challenges through innovative solutions and sustainable practices. The successful reduction in reconstruction depth, strategic use of geogrids, and incorporation of recycled materials led to a durable and efficient road structure. The project’s completion 8 weeks ahead of schedule, with minimal disruption to the community, highlights GW Highways’ commitment to delivering high-quality infrastructure while enhancing local economic benefits. The A299 Thanet Way project exemplifies GW Highways’ ability to adapt to challenging conditions and deliver a resilient, long-lasting road asset. The project’s innovative innovative engineering, sustainability practices, and support for the local economy set a high standard for future infrastructure projects.
Wembley High Road, a familiar and essential route weaving through the heart of Wembley, had begun to show the strains of time and the challenges of persistent drainage issues. Recognising the importance of this vital link for residents, businesses, and the wider community, Brent Council embarked on a significant upgrade project. We were entrusted with the task of breathing new life into this well-used thoroughfare, ensuring its long-term strength and reliability. The existing road surface bore witness to the years of service, with the underlying drainage struggling to cope, leading to the gradual development of imperfections. The need was not just for a repair, but for a comprehensive renewal that would address the root causes and provide a lasting solution, enhancing the everyday journeys of those who rely on Wembley High Road.
We approached the project with a commitment to both robust engineering and mindful execution to implement a foundation for the future, whilst respecting the present. The reconstruction involved a deep renewal of the road’s foundations, coupled with the installation of a modern drainage system designed to effectively manage water and protect the new surface from future challenges. This fundamental work laid the groundwork for a durable and reliable road. The process of reconstruction unfolded with careful attention to detail. The old surfaces were thoughtfully removed, with a significant portion of the materials being recycled and given a new purpose within the project – a testament to sustainable practices. New layers were then meticulously laid, culminating in a smooth and even surface that promised a more comfortable and safer passage for all.
Throughout the project, we worked diligently to minimise disruption, understanding the importance of Wembley High Road to the local community. Our efforts led to the road being reopened to traffic on a temporary surface nearly a month ahead of schedule, a welcome relief and a demonstration of our commitment to efficiency. The final touches to the surface followed swiftly, completing the transformation. The revitalised Wembley High Road now stands as a testament to careful planning, skilled execution, and a commitment to the community it serves. The upgraded infrastructure provides a stronger, more reliable link for everyone, ensuring smoother journeys and contributing to the vibrancy of the Wembley area for years to come. We are proud to have played a key role in this renewal, helping to secure a brighter journey for all who travel this important road.
Northwall Road in Deal experienced significant structural failures, causing persistent maintenance issues and road safety concerns. Investigations revealed that the underlying problem stemmed from a weak Cement Bound Granular Material (CBGM) base, which had deteriorated due to the local sandy native ground. The CBGM failed because the local sand lacked the necessary stiffness to support a composite pavement, as the CBGM had been overlaid. To provide a long-term solution, we undertook a comprehensive reconstruction project to stabilise the foundation and deliver a durable, flexible road surface.
A thorough site evaluation was conducted to determine the root cause of the road’s deterioration. Key findings included:
• The CBGM base had weakened prematurely, failing to provide adequate structural support.
• The underlying sandy native ground lacked the necessary stiffness to sustain a composite pavement, leading to the CBGM’s failure.
• Continued failure led to surface cracking, settlement, and water ingress, accelerating the degradation process
To ensure the longevity of the asset, we utilised our previous experience and extensive knowledge to refine our reconstruction strategy and engineer a resilient solution:
• The compromised CBGM base was completely removed to eliminate future structural weaknesses.
• Geogrids were introduced to reinforce the subgrade, preventing lateral movement and improving load-bearing capacity.
• A high-quality Type 1 granular subbase was installed, providing a stable foundation for the new flexible road construction.
• A carefully engineered flexible pavement was laid, designed to adapt to environmental conditions and long-term traffic loads.
With meticulous planning and execution, the reconstruction process ensured minimal disruption to local traffic and businesses:
• Advanced machinery was utilised to efficiently remove the defective base while preserving surrounding infrastructure.
• Stabilisation measures, including precise geogrid placement and material compaction, were rigorously applied to enhance ground resilience.
• The final flexible pavement was installed using industry-leading materials and construction techniques to guarantee longevity
The completed works on Northwall Road have resulted in a vastly improved and sustainable roadway. Key benefits include:
•Enhanced road performance and resistance to future ground movement.
•A significantly reduced need for ongoing maintenance and costly repairs.
•Improved ride quality and safety for all road users.
•By addressing the fundamental structural issues and implementing a future-proof design, we have successfully delivered a long lasting road solution that will serve the Deal community for many years to come.