Tricel NOVO EN6-50, User Manual

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The following materials are approved as primary backfill:
Rounded pea gravel:
Minimum particle size 3mm, maximum 18 mm, compacted to a relative density of >70%. Gravel shall be
clean and free flowing, free from large rocks, dirt, sand, roots, organic materials or debris. Upon
screening analysis the backfill material shall have no more than 5% by weight passing 2.36 mm Sieve
Or
Crushed or processed stone:
Minimum particle size 3 mm, maximum 12 mm, compacted to a relative density of >40%
Dry Gravel density must be at least 1500 kg/m
3
. Material should be washed or screened to remove fine
particles. Upon screening analysis the backfill material shall have no more than 5% by weight passing
2.36 mm sieve
Use of other than specified backfill and bedding materials will void the tank warranty.
Backfill material shall not be frozen or contain lumps of frozen material at any time during placement.
Pea Gravel Crushed Stone
10.6.2 Concrete backfill specification
:
Semi dry concrete 25n grade with a ratio of 4.5 aggregate to 1 cement.
Note: Standard concrete mixes should not be used, where sulphates or similar aggressive chemicals are
present in the groundwater.
Lift height (rate of rise):
Determine the lift height (m), or rate of rise (m/h) for the specific concrete type used, to ensure that a
design pressure (P max) of 15kN/m
2
on the tank is not exceeded.
Vibration:
The tank design assumes minimal compaction of the surrounding concrete. Where necessary, this may
be extended to include light internal vibration. Never use deep revibration which will substantially
increase the pressure on the tank, possibly causing failure.