Screed replacement in FitX studio
Berlin - Germany
Even before the opening of a new studio in Berlin, its operator, Essen-based FitX Deutschland GmbH, was confronted with a major problem: The screed of the approximately 500 m² free weights area on the ground floor had an average flexural strength of only 4 N/mm² instead of the required 7 N/mm². Immediate rehabilitation was necessary – with only a few weeks to go before the planned opening date in August. General contractor André Bahnsch, Managing Director of Bahnsch GmbH, commissioned Sandro Schröder's specialist screed-laying company in Pritzwalk to carry out the work – with an immediate start date. He in turn confidently presented the challenge to MC sales representative Steffen Suenboldt, who was quick to provide the advice and assistance that the screed-laying specialist required.
A screed for special tasks
Not only was the timeline in Berlin extremely tight, the specified F7 flexural strength (7 N/mm²) was also a difficult ask. Achieving such “bending tensile” strength values reliably often poses a problem for earth-moist screeds, due to the fact that compaction is inherently low. However, if the F7 target were to be missed a second time, it would have been a disaster – not least because the subsequent trades were by this time already behind schedule. The solution to the problem? Powerscreed rapid. This high-performance hardening accelerator for the production of screeds that allow early walk-on accessibility and overworking not only saves a great deal of water, it also considerably increases the material’s early and final strength values. Special microcrystals with a cement-like surface structure catalyse the hydration of the cement, accelerating the drying process. In addition, screeds with low w/c values can also be used to good effect.
Together with screed specialist Schröder, the MC team developed an individual screed mix for this special undertaking. The aim was to ensure that the desired strength would be achieved through increased use of cement combined with the strength-enhancing Powerscreed rapid accelerator. The risk: The application of higher cement ratios can inhibit workability. Yet here, too, Powerscreed rapid showed its capabilities by actually significantly improving the processing properties of the screed, enabling the entire 500 m² area to be completely re-laid in just two days.
The site work was further supported by MC to ensure achievement of the required mechanical properties during the drying process. The screed exhibited a flexural strength value of 6.16 N/mm² after ten days and 7.56 N/mm² after 28 days – needless to say, very much to the delight of the screed layers, the site manager and the client alike. And the studio did indeed open on schedule in August 2018.