Equilibrant Ltd were commissioned by WJM Building Services, on behalf of the Education Authority NI, to carry out a Special Inspection of Portrush Primary School. The purpose of the Special Inspection was to determine the source, extent and significance of deterioration to the reinforced concrete window surrounds, around the external perimeter of the school. The Special Inspection included the following:
- Materials Testing for chloride analysis and cement content analysis;
- Carbonation depth measurements;
- Full delamination survey from ground floor/MEWP;
- Concrete resistivity readings;
- Detailed Auto CAD drawings of each elevation including developed sections showing areas for concrete repair;
- Comprehensive Materials performance specification in accordance with BS EN 1504;
- Comprehensive repair methodology.
The Special Inspection concluded that the reinforced concrete window surrounds were in poor condition with widespread corrosion initiation and propagation observed. 60% of dust samples tested revealed a chloride ion by mass of cement greater than the prescribed threshold of 0.4%. The highest chloride ion content by mass of cement was 2.44%, significantly exceeding the recommended threshold. The source of the observed deterioration was chloride induced corrosion of the embedded steel reinforcement with low cover. This localised corrosion initiation has manifested in cracking, thereby permitting clear access to the steel reinforcement for concrete carbonation which has exasperated the corrosion process.
Equilibrant Ltd provided the Education Authority NI with a detailed plan of repair areas and a comprehensive materials performance specification and repair methodology allowing sustainable remedial works to be carried out.