The works carried out were primarily aimed at repairing and improving the reinforced concrete structural elements that make up the "Pipe-Racks" of the Portucel Viana industrial facilities.

The concrete elements showed a significant degree of deterioration, making it urgently necessary to apply repair and reinforcement techniques to halt their progressive degradation.

The highly aggressive environment – due to corrosive chemicals and the proximity to the marine atmosphere – and the total lack of prior surface protection were the most relevant factors contributing to the deterioration observed over 30 years.

Main works carried out

As a result of multiple layout changes at this production unit over the years, adaptations had been made on the pipe racks, increasing the stress placed on these structural elements. New pipelines and intermediate supports for new equipment had been installed.

The intervention included the execution of the following works:

• Cleaning of concrete surfaces.
• Cleaning of metal angles.
• Demarcation of concrete repair zones.
• Chipping and preparation of concrete surfaces.
• Treatment of corroded reinforcement with corrosion inhibitors.
• Reconstruction of concrete surfaces.
• Crack sealing with epoxy resin.
• Crack injection with epoxy resin.
• Structural strengthening with composite materials.
• Protection of concrete and steel angles with paint. 

The analysis of the proposals submitted for tender revealed that part of the strengthening design using composite materials – carbon fiber laminates and fabrics – was highly deficient.

Additional information

The technical competence and reliability demonstrated by Stap during the proposal phase were key to winning the contract. It was the company’s expertise in structural reinforcement methods that led the project owner to award the contract to Stap, even over other bidders offering lower prices.