Strengthening and Waterproofing of the Vascão Bridge
The intervention on the Vascão Bridge forms part of a project for the rehabilitation and structural strengthening of road infrastructure, with an approximate investment of €2.9 million.
This bridge, inaugurated in 1946, carries the National Road 122 (EN122) over the Vascão stream and has a total length of 65 metres. The main objective of the works was to extend the service life of the structure, ensure the safety of road traffic, and improve the bridge’s structural durability.
Project Description
Situation
After several decades of service, the bridge showed signs of deterioration of the deck and deficiencies in waterproofing, which encouraged water infiltration and the subsequent degradation of the lower layers and the steel structure.
These defects posed a risk to structural stability and compromised the safety and comfort conditions of the roadway, making a major intervention necessary to ensure its rehabilitation and extend its durability.
Solution
The technical solution adopted consisted of the complete replacement of the existing deck and the application of a high-performance waterproofing system, based on an anionic waterproofing emulsion with an application rate between 1.5 and 1.8 kg/m², over which a glass fibre reinforcement grid with integrated geotextile — S&P Glasphalt GV — was installed.
This system prevents the propagation of cracks from the concrete into the bituminous layers, avoiding water infiltration and, consequently, the deterioration of the lower layers and the steel structure. In this way, it contributes to greater strength and durability of the entire structure.
On top of the waterproofing system, a levelling course AC 4 and a wearing course AC 14 with a thickness of 5 cm were applied, restoring optimal traffic conditions.
With this intervention, significant benefits were achieved, namely:
- Structural strengthening and increased bridge safety;
- Effective waterproofing that protects the new structure against infiltration and aggressive agents;
- Extension of the infrastructure’s service life, reducing future maintenance costs;
- Improved driving conditions and user comfort.
Material
600 m² S&P Glasphalt GV
