15
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/m3. 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
5.7
Concrete Specification
Semi dry concrete 25n grade with a ratio of 4.5 aggregate to 1 cement.
Important:
•
Standard concrete mixes should not be used, where sulphates or similarly 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/m2 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.
•
Impact of concrete on discharge:
Under no circumstances should concrete be discharged directly
onto the tank.
Summary of Contents for Pumping Chamber 2600
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Page 23: ...23 6 1 1 Operating Performance Tricel 75...
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Page 26: ...26 6 2 1 Operating Performance GRI 11...
Page 35: ...35 Notes...
