Reinforcement of DK6 Road
Location
National Road No. 6 (currently a section of Provincial Road DW112) on the Szczecin-Gdańsk route, West Pomeranian Voivodeship, Malechowo, Poland.
Year of construction
2007
Project Description
Situation
Prior to the rehabilitation works, the pavement of National Road No. 6 exhibited significant deterioration resulting from many years of service under heavy traffic loads. Geotechnical investigations and pavement coring revealed:
- A multi-layer asphalt pavement structure with non-uniform composition
- Tar-bound layers containing numerous cracks
- A cracked and partially deteriorated lean concrete base
- Localised sections with limited load-bearing capacity
- Numerous reflective cracks likely to propagate into new asphalt layers
The original design called for milling the pavement to an average depth of approximately 14 cm. However, following site investigations and exploratory works, the milling depth was reduced to 8-9 cm. As a result, it became necessary to implement a solution capable of increasing pavement durability without complete replacement of the existing structure.
Solution
To mitigate crack propagation and enhance the long-term performance of the pavement, an interlayer reinforcement system based on two types of S&P reinforcing grids was incorporated.
A layer of S&P Glasphalt® G fibreglass grid was installed on the milled pavement surface, covering approximately 7,300 m². A 6 cm asphalt binder course was then placed above the grid.
Subsequently, S&P Carbophalt® G, a glass-carbon composite grid, was installed over the binder course across an area of approximately 7,200 m², followed by the placement of a 3 cm asphalt wearing course.
On roadway widening sections, S&P Glasphalt® G was additionally used to reinforce 2 m-wide pavement extensions on both sides of the carriageway.
Results and Conclusions
The application of two layers of composite reinforcement enabled the pavement structure to be adapted to the actual site conditions while significantly reducing the risk of premature distress. Despite the reduced milling depth and prolonged exposure to heavy traffic, the pavement has demonstrated excellent long-term performance.
The effectiveness of the solution was further verified during periods of increased traffic associated with the construction of the S6 Expressway. After nearly two decades of service, the pavement structure continues to meet operational requirements, confirming the effectiveness of S&P Glasphalt® G and S&P Carbophalt® G grids in mitigating reflective cracking and extending pavement service life.
The Malechowo project serves as an excellent example of the successful rehabilitation of an existing roadway structure without the need for full reconstruction, providing a durable and cost-effective pavement renewal solution.
Material
S&P Glasphalt® G
A fibreglass reinforcement grid designed for asphalt pavement applications. Owing to its high tensile strength and low elongation characteristics, it effectively limits the initiation and propagation of reflective cracking.
S&P Carbophalt® G
A composite reinforcement grid manufactured from glass and carbon fibres. It is used to increase pavement structural stiffness and improve both fatigue resistance and resistance to rutting.
