The polypropylene fibres are mixed into the concrete mixture either already in the concrete production plant or at the construction site. The reinforcing effect of the fibres FIBRIBET ® depends among others, especially from their quantity and even spread in the whole volume of the cement matrix. Admissible quantity of water for the production of concrete, screed, plaster and mortar must be upheld and must not be exceed. Polypropylene fibres FIBRIBET ® do not require any further modifications.