Repair and remodeling of "pipe-racks" at Portucel's Viana plant

The concrete elements were significantly degraded and required the immediate application of strengthening and prevention techniques to stop the deterioration process.

As a result of several layout changes in this factory over the years, the “pipe-racks” suffered many adaptations that increased the load on their structural elements. New ducts and intermediate supports were installed to accommodate new equipment.

The highly aggressive environment, with its corrosive chemicals and proximity to the sea, to which the surfaces had been exposed during their 30 years of existence, and the lack of any protection were the main causes of the deterioration found.

The intervention involved the following tasks: Cleaning the concrete surfaces; cleaning angle irons; marking the concrete areas to be repaired; picking and preparing the concrete surfaces; treating the oxidised strengthenings with corrosion inhibitors; rebuilding the concrete surfaces; sealing cracks with epoxy resins; injecting epoxy resin into cracks; strengthening with composite materials; protecting concrete and angle irons by painting them.

The success of this intervention was due mainly to the high technical skills of all Stap personnel, from project managers to foremen.

The analysis of the items put to tender showed that part of the strengthening project using composite materials- carbon fibre laminates and fabrics - was very deficient. Stap's sound qualifications were critical during the bid negotiation phase, and it was our technical expertise in this structural strengthening methodology that made the Owner of the Works choose Stap for the job over other competitors whose bids were lower.

The ability of the works manager, in the person of – Mário Correia, who coordinated the work teams, and André Coelho, who supervised and provided support for the works, were critical to carrying out the project at a steady rate (the job took 7 months to complete) and to overcoming the problems encountered, due to a highly segmented concrete structure with different sizes and pathologies.