Plant rooms, operating theatres and recovery rooms at the University Hospital of North Tees in Stockton-on-Tees were in need of renovation due to a prevalence of cracking and spalling in the structure’s concrete surface as a result of low cover carbonation. Due to the specialist nature of the medical work being carried out in some of the areas involved, repairs had to be completed as rapidly as possible and with as little disruption to hospital staff, patients and their families. To this end, Sika MonoTop, a proven concrete repair system for a range of infrastructure projects, was specified for the high-profile hospital refurbishment.
The hospital’s repair programme, which began in October 2019, was carried out by CSC Services UK Ltd. It covered an area totalling 1,000m2 and involved contractors working in wintery conditions and at weekends in order to complete the project to the two-month deadline agreed with client, North Tees and Hartlepool NHS Foundation Trust.
Initial repairs involved applying Sika FerroGard-903+, a surface-applied mixed corrosion inhibitor. This ingenious solution, which is based on organic compounds, is designed for use as an impregnation of steel-reinforced concrete. It is spray-applied and penetrates concrete to form a protective monomolecular layer on the surface of the reinforcing steel, thus delaying the corrosive process and the rate it progresses. The exposed steel reinforcement was applied with Sika MonoTop-610, a high-performance, one-component, cementitious polymer-modified primer. Spray-applied, Sika MonoTop-610 simply required mixing with water to provide a superb, anti-corrosive bonding in lieu of applying a high-build concrete repair mortar: Sika Monotop-615.
SikaMonoTop-620, a one-component cementitious polymer modified mortar, provided the repairs’ smoothing coat. Sikagard-552 W Aquaprimer was used as the adhesion promoting primer for Sikagard-550 W Elastic, the repairs’ solvent-free, crack-bridging, plasto-elastic anti-carbonation coating.
Mark Lemon Managing Director at CSC Services, said: “This was an extremely high-profile project, which required a proven concrete repair and protection system. Sika MonoTop is a leader in its field; its simple application is matched by its excellent, long-term performance. The system comes with a 10-year guarantee, which gave the client peace of mind that repairs were completed to the highest specification.”
Denise Maguire Editor of Irish Construction Industry Magazine