Base
The base must be undamaged, clean, and damp enough to be darker in colour. If necessary, remove the weak-strength cement paste layer. Best adhesion can be achieved to a rough base. The mould must be tight, because the grouting concrete is very pliable and flows easily. Normal casting can be carried out from one side. Thus, build that side's mould higher than usual and, if necessary, also wider, so that the grouting concrete can fill the casting space under its own weight. When using galvanised steels, you must make absolutely sure that the coating has become passive.
Mixing
Refer to the bag for how much water the concrete requires. Add the dry material to the water and mix with a concrete mixer for around ten minutes. With a power mixer, around one to three minutes of mixing is sufficient. Let the plaster stand for around five minutes and mix it again for a short while. Find the correct consistency at this stage by gradually adding the rest of the water. We do not recommend adding all of the water right at the start. The finished concrete remains workable for around one hour.
Work instructions
We recommend casting as soon as possible after mixing the mass, as this allows the full utilisation of the expansion of the fresh mass. The mass is so pliable that compacting is not usually necessary. The flow can be enhanced by ramming or light vibrating. When doing thick casting layers (over 50 mm), you should do the casting in several layers. Each layer must be allowed to harden for at least one day before the next casting. Another method for thick casting layers is to add coarse aggregate (6-10 mm) (around 15% of the weight of the dry mixture) to the concrete. You should, however, perform advance testing. Do not allow the freshly cast concrete to freeze. The lowest usage temperature is + 5°C.
After treatment
You must care for the cast surface by spraying with water and/or protect it with a plastic film. The need for aftercare depends on the conditions. It should continue for at least one to three days.
Storage and handling of waste
See the separate storage and disposal instructions https://www.fescon.fi/en/material-bank