Renovation of an underground parking garage in Elmshorn, Germany
The concrete floor of a 29,000 sq.ft. underground parking garage was heavily deteriorated from from de-icing salt attack. The renovation was planned in two stages to keep at least 50% of the parking spaces available for the tenants during the works. As the project was time critical the owner decided to use a heady duty cementitious coating system based on VELOSIT SC 253.
Substrate preparation of the first stage of approx. 15,000 sq.ft. was done by scarifying followed by shot blasting. The prepared surface was primed with an epoxy primer with a full broadcast of quartz sand. On the following day a self leveling flooring system based on VELOSIT SC 253 and #40 sand was installed in 1/4 inch thickness. Mixing was performed in an automated pump truck delivering 6 tons per hour at the end of the hose. Theoretically the machine could supply 20 tons per hour but that exceeds the amount that a 3 man crew can install at this thickness. The coverage was around 970 sq.ft. per ton and slightly higher than the calculated amount due to surface roughness. The installation of 16 tons required less than 3 hours and was open to foot traffic after another 3 hours. The floor had already achieved 6,000 psi compressive strength the next day and was opened to regular traffic. The final strength after 28 days reaches approx. 10,000 psi.
Both phases of the project consumed a total of 30 tons self leveling based on VELOSIT SC 253. The owner is very satisfied with the surface and plans further projects with the system.