The trays are produced from heavy weight concrete of grade B20 (M 300); frost resistance is F300, water resistance is W6.
For your information:
Telescopic trays B-6 are used for the arrangement of prefabricated drainage structures on highways. Telescopic trays are designed for drainage from road and bridge structures, as well as for drainage of storm water in road and civil construction.
REINFORCED-CONCRETE NON-PRESSURE SPIGOT PIPES / TILE UNDER TS PIPE (PTS)