11/28/2022

Along the hilly southern edge of Europe, drivers on the A9 highway can eat croissants for breakfast and chorizo for lunch. This highway — which flows seamlessly from France into Spain – serves as a crucial artery from Europe to North Africa. Opened in 1976, it is one of the most frequently used highways in France.

Map of Le Boulou bridge refurbishment
Image: The French-Spanish highway had to be reinforced and widened

But over the years, traffic has weighed on the bridges, which carry more than 15 million users per year and 40,000 vehicles per day. One out of four of these is a heavy vehicle.

With heavier truckloads, road safety became jeopardized. Therefore, sections of the highway had to be reinforced and widened from four to six lanes, and Sika’s expertise and technologies proved invaluable for the job.

Therefore, in 2010, the EUR 520 million project began of widening and refurbishing the highway along one 40-kilometer stretch. It was divided into three sections between Perpignan north and south, and between Le Boulou and the Spanish border. The improved highway section between Montpellier and Spain opened in September 2016.

The repair work was carried out at night and under the bridge
Image: The repair work was carried out at night and under the bridge

Into the Great Wide Open

One of the biggest challenges while modernizing the highway was strengthening the bridge piers in poorly accessible terrain. In a mountainous remote area, the engineers had to refurbish thirteen structures, including four viaducts.

The work consisted of reinforcing the heads of the viaduct pillars from a platform hung on the current pier. These pier caps supported metal beams with a crane from the highway. “The operation was spectacular, especially since this work was carried out at night, and under traffic," Paul Delplace, the Eiffage Génie Civil project director of the site, told a French newspaper in 2018.

The reinforcement work had to take place with the highway open to traffic. “By using Sika products, we could widen the bridge while keeping the road open. We basically worked under the bridge, so had no influence on the traffic,” Julien Couverchel, business development manager at Sika, said. 

The widening of the A9 was a colossal and complex project
Image: The widening of the A9 was a colossal and complex project

The widening of the A9 was a colossal and complex project which required tight control of the structure. Sika provided training for applicators and supported the project with technical advice.

Sika products were used abundantly – 16,000 meters of Sika® CarboDur® carbon fiber-reinforced polymer plates reinforce the structure supporting the bridge sections; 3000 square meters of SikaWrap®-230 C carbon fiber fabric protect the bridge piers against vibration and wear; and 8,000 kilograms of Sikadur®-30 and 3,000 kg of Sikadur®-330 were used to attach and protect the reinforcement systems.

Today, the result is a far more fluid and secure highway which can withstand heavier traffic. This Mediterranean axis plays a major role in the tourist and economic development of the Catalonia region. 

Most of the time, refurbishment is far less wasteful than demolition
Image: Most of the time, refurbishment is far less wasteful than demolition

Refurbish vs. Free Fallin’

Bridges like the A9 in Le Boulou – plus tunnels, railways, and other public facilities – are essential to the functioning of society. They are often designed to last for over a century. This durability can be achieved with high-quality materials and design, but it can also happen with excellent maintenance.

Most of the time, refurbishment is far less wasteful than demolition. Moreover, it can maintain the original look and feel of old structures with character. Sadly, not all buildings are suitable for refurbishment. But Sika has fully embraced the circular economy principles to develop innovative products so we can restore, repair, and protect as much existing material as possible. 

Seismic investments are currently underway which will improve the quality of life for the collective by upgrading infrastructure. Not only is Sika adding durability to these massive projects, but the company is also helping ensure that high standards are met. This is important because since 1980, the number of building codes written into law has increased exponentially in every major developed country. 

At a time when resource scarcity and high costs have become major limiting factors for the construction sector, Sika is making refurbishment more attractive and is pushing the boundaries of science to cultivate an industry mindset of doing more with less.