Brazil Highway Tunnels Gain Durability and Ability to Self-Heal Concrete Walls with Penetron Technology

The completion of the Contorno de Florianópolis (BR-101) in March 2024 provides a crucial highway bypass for the Florianópolis region in southern Brazil. The Penetron System of crystalline concrete waterproofing products was specified to ensure the impermeability and durability of the concrete tunnel walls.

Located about 700 km (435 miles) southwest of São Paulo, Florianópolis is the capital of the state of Santa Catarina in the south of Brazil. The seaside city of over 500,000 inhabitants is famous for its 16th century fortress in the city center and beaches on the island of Santa Catarina, including the popular Praia dos Ingleses resort and the Lagoa da Conceição, a saltwater lagoon considered a haven for windsurfing and boating.

The Contorno de Florianópolis project was devised to counter the congestion of the region’s increased road traffic. It comprised a new four-lane highway approximately 51 km in length, including viaducts, bridges, interchanges, and two (1.6 km long) tunnels. As the largest recent highway construction project in Brazil, this new BR-101 bypass road now diverts heavy traffic away from the Florianópolis metropolitan area, reducing congestion and improving traffic flow.

“This new stretch of the BR-101 highway is designed for an operational speed of about 100km/h by avoiding steep slopes and tight curves to allow drivers to maintain a steady speed typical of an express corridor,” adds Cláudio Neves Ourives, CEO and Managing Partner of Penetron Brazil.

Penetron was tapped by Arteris, the general contractor, to provide the waterproofing solution to protect the concrete structures of the highway tunnels from deterioration due to groundwater penetration (i.e., moisture) , chemical attack, and carbonation. PENEPLUG, a rapid-setting, crystalline compound, was first applied to stop active leaks in the tunnels. After proper preparation of the concrete surfaces of the walls, PENECRETE MORTAR, a crystalline waterproofing repair grout, was used to fill any gaps and to repair any cracks (wider than 0.5mm) in the concrete walls. PENETRON, a crystalline waterproofing material, was then topically applied to the finished walls to permanently protect the whole structure.

Once applied to a properly prepared surface, the active ingredients in PENETRON and PENECRETE MORTAR permeate deeply into the concrete matrix, forming an integral crystalline structure throughout the pores and capillary tracts to block water ingress. This prevents the deterioration of concrete due to water penetration, chemical attack, and carbonation, ensuring the long-term performance of the highway.

“All Penetron crystalline products are non-toxic and contain no VOCs, making them safe for both construction workers and the surrounding environment,” explains Cláudio Neves Ourives. “Applying the Penetron System ensures the concrete tunnel walls of the BR-101 will remain structurally sound, and minimizes the need for any future moisture-related repairs and maintenance. This helps reduce lifecycle costs associated with the highway infrastructure.”