An innovative UV cured protective coating manufactured by Flexcrete Technologies Limited has been used for an external refurbishment of the McCain Foods French fry plant in Grand Falls, New Brunswick, Canada.
The Flexcrete coating, Monodex UVC, was specified for application to the external walls of the precast concrete building, totalling a surface area in excess of 2,000m². The production plant was originally constructed in 1970 and annual production is 86 million kg of French fries.
Over time due to weather penetration and frost damage, the concrete had deteriorated. The walls are constructed from precast concrete structural wall T sections, which are insulated sandwich construction with 50mm rigid insulation and a 50mm interior concrete liner. An Engineer’s report concluded that the overall structural system was still in good condition but there were areas of deterioration in the exterior T-sections where cracking and spalling was evident. Although of no immediate concern, it was felt that it would become a serious structural threat if left untreated. Flexcrete’s Canadian distributor, RCJ Concrete Restoration & Coatings Inc. proposed the use of Flexcrete products, having used them successfully on several projects previously for McCain.
McCain Foods was originally founded in Canada in 1957 and has grown to become a global leader amongst food processors. The business now employs more than 17,000 people across six continents and 41 sites. McCain products can be found in more than 160 countries and one in every three French fries in the world is a McCain fry.
A complete package of concrete repair and coating materials was supplied by Flexcrete for the external refurbishment. As the substrate was heavily contaminated with fatty acids and micro-organisms were present in the pores of the concrete, the surface was first treated with Biodex Wash which neutralises active mould, fungal and bacterial growth. Steel Reinforcement Protector 841 was then applied to the re-bars and due to the significant depth of repair needed to the concrete T sections, Monolite, an ultra-high build, lightweight cementitious mortar, was used as its low sag properties enable it to be built up to 100mm in a single application, even on these vertical surfaces. To assist in replicating the original line of the member, a timber form was used along the sides of the repair.
Following the repairs, Monodex UVC, an advanced, waterborne, UV cured acrylic coating, was applied to the external walls. The surface of the applied liquid coating cures by using a chemical process called cross-linking. This is initiated by exposure to UV radiation to form a tough, hard-wearing surface with excellent weathering resistance but with a softer underlying core which is highly elastomeric, enabling it to bridge cracks which may exhibit future movement.
Supplied as a single component product, Monodex UVC is especially suited for use in the extreme climatic conditions found in New Brunswick. It is able to accommodate thermal expansion and contraction in structures without cracking, even in extreme temperature conditions ranging from -50°C. to +80°C. It also contains the latest encapsulated biocide technology to prevent mould growth whilst a highly dirt resistant finish means it maintains an attractive appearance throughout its lifespan. It provides excellent protection against the damaging effects of carbonation and will last at least 15-20 years before first maintenance is required.
In areas highly susceptible to cracking, the coating was reinforced with Cemprotec GFM225 glass fibre matting. Crucially for this project, Monolite and Monodex UVC are both waterborne and virtually odourless so there was no risk of foodstuffs being contaminated in the processing plant.
Flexcrete Technologies Limited is the UK’s leading independent manufacturer of technical mortars and high performance coatings. With origins dating back to 1983, the company manufactures a wide range of concrete repair mortars, fairing coats, waterproof cementitious coatings and decorative protective coatings. With its head office and manufacturing complex based in Leyland, North West England, Flexcrete products are available from stockholding distributors all around the UK. The company also has a global presence through international agents and distributors in 65 countries worldwide with export sales accounting for over 50% of its business.