The insulation and underfloor heating pipes had already been laid out for the installation of a flowing screed, so work on installing the VELOSIT SC 245 flowing screed could begin at 8:30 a.m. KKL loaded one of its Brinkmann Transmix 3200 machines with 16 tons of a specially formulated 0-4 mm screed sand mixture and filled the binder silo with 7 tons of VELOSIT SC 245. After a few minutes, the water quantity was adjusted by controlling the discharge rate and installation could begin. In less than 2 hours, a good 20 tons of screed had been pumped onto the second floor. The installation is comparable to an anhydrite screed and eliminates the need for mechanical compaction of the material, as is the case with earth-moist cement screed.
The Transmix now had to be refilled, and in the afternoon the surface was laid on the first floor. At this point, the first surface was already accessible and pleasantly warm due to the hydration heat. VELOSIT SC 245 develops high flexural and compressive strengths very quickly. When the area was inspected the next day, the compressive strength was already 22 MPa. The three partners Andreas Kückmann, René Krüger, and Thorsten Lux from KKL were delighted with the very even and crack-free surface. The Delbrück-based screed specialists see enormous potential for this system, especially when larger areas need to be ready for use again quickly, as is often the case in the renovation of industrial areas, for example.
By the following Monday, the surface had dried sufficiently for tiles to be laid in the first apartment, and it was so even and stable that it did not need to be sanded.
The high strength also allows for relatively thin screed structures. Despite the strong exothermic reaction, there are virtually no stress cracks. Since VELOSIT SC 245-based flowing screeds have similar thermal expansion behavior to concrete, the field sizes and design of edge connections must be dimensioned in the same way as for cement screeds.
Self-leveling screeds made with VELOSIT SC 245 harden into a water- and frost-resistant screed slab. They can be installed in a composite layer from 10 mm and on a separating layer from approx. 35 mm layer thickness. With the heating protocol for underfloor heating, work can begin after just 24 hours.
For smaller areas, the VELOSIT SC 244 ready-mixed screed is also available, which is based on the same technology and contains an optimally balanced sand mixture in addition to the binder.
VELOSIT flowing screeds combine the processing advantages of an anhydrite flowing screed with those of a cementitious rapid screed. Easy to install, quickly ready for covering, and also suitable for permanently wet areas.
