12/03/2021
The quality of reinforced concrete installation and repair is vital to upholding the structural integrity of a wide range of applications from bridges to tunnels, to domestic basements, buildings and car parks. Hence the need for a European standard: BS EN 1504, which sets out how this process can be carried out with optimal effect.
Comprising 10 parts, BS EN 1504 relates to ‘products and systems for the repair and protection of concrete structures – definitions, requirements, quality control and evaluation of conformity’.
Get the specification right
Correct specification is crucial to concrete repair and structural strengthening, as failure to treat a particular issue with an appropriate solution can have serious consequences in terms of a building’s long-standing stability and the costs incurred in reversing poorly-prescribed refurbishment. BS EN 1504 provides an excellent reference point in relation to this matter by offering some best practice to correct product specification for reinforced concrete repair.
Good planning is key to quality refurbishment and as BS EN 1504 guidance states; this should include an assessment of the debilitated concrete whilst taking into consideration the structure’s original design, current condition, its history and its surrounding environment. According to the standard, repair options should be based on a building’s use and design life, as well as a repair system’s performance.
Key principles and solutions
EN 1504 standards define 10 principles for concrete repair and the methods for achieving them. They include protection methods to safeguard against ingress of chemicals and water, and moisture control. It also highlights the principle behind treating rebar corrosion using cathodic control, a method that was further developed in the 1990s and trialled the successful use of galvanic anodes. The revelatory studies led to Sika developing its own galvanic solution: Sika® Galvashield® XP. This system – which comprises embedded galvanic anodes – not only addresses the source of concrete corrosion, is proven as a cost-effective repair solution as it minimises ongoing maintenance costs and extends the life of the structure itself.
CPD guide
Sika® Galvashield® XP is one of a range of concrete repair and protection solutions devised by Sika, which has put its specialist knowledge in this field to further beneficial use with the creation of a CPD module. The presentation is aimed primarily at engineers and surveyors. It looks at BS EN 1504-compliant repair and protection solutions involving mortars and other materials. It also provides valuable guidance on a range of concrete repair and protection topics including inspection and testing procedures, structural strengthening and corrosion management systems such as migratory corrosion inhibitor, Sika® FerroGard®.
Used to treat carbonated structures, Sika® FerroGard® is a surface-applied liquid which penetrates the damaged concrete and forms a passive layer around the reinforced steel, thus delaying the corrosion process and reducing its rate. This simple time and cost-effective practice increases structural service and maintenance lifecycles by up to 15 years when used as part of a Sika’s Total Corrosion Management offering.
The long-term repair and protection of concrete structures is not only crucial to preserving the buildings themselves, it can be seen as an act of sustainability, as it will reduce the need to construct fewer new buildings, thus minimising emissions and material waste. Therefore, safeguarding today’s built environment could significantly contribute to creating a cleaner world for generations to come.