31-05-2017, 09:41 AM
Bentonite is a moisture retaining clay used as a ground electrode filler to help decrease soil resistivity. Bentonite clay is a sodium-activated montmorillonite which when mixed with water swells to many times its original volume.
If underground power cables are required to operate with the maximum direct burial degree when installed in the cable conduit, the cable conduit must be filled with bentonite mixture (100 parts bentonite / water mixture 10: 1 to 20 Parts of sand and 8 parts of cement).
The bentonite mixture must be pumped into the cable conduit so as to completely exclude the air and upon completion the filling will be sealed to avoid any leakage of bentonite mixture.