G.I Earthing Strip Coating

What standard?

Is bitumen a good conductor?. It should not act as a barrier between the metal earthstrip and the ground.

I presume that by "Galvanium", you mean zinc. Galvanized Iron is iron coated with zinc. When you say "G.I. Earth Strip", is this strip inside a machine or junction box, or is it in contact with the earth (ground, soil)? If it is in contact with the soil, it should be heavily copper coated, not zinc coated. Definitely NO on the bitumen! Tar (bitumen) is an insulator, and would defeat the purpose of the earth/ground connection.

I hope these links will help satisfy your curiosity.

Grounding Electrodes-http://www.nachi.org/grounding-electrodes.htm

Commercial Grounding Installations-http://www.sankosha-usa.com/pdf/san-earth-tech.pdf

Since you don't know very much about electricity, you should put this project into the hands of a qualified electrician. Improper grounding can result in extensive property damage and loss of life.

if the GI earth strip is connected to the actual earthing bar than it is ok to insulate with what ever means .In some places GI coated steel cables are used instead of insulated cables due to cost or deter thefts. what ever done the end result is you must get the required min earth resistance to meet your installations requirement.

If strip is not insulated the area in contact with earth increases and measured resistance will be less.

I belief the galvanised strip is just acting as a conductor from the frame to the actual earth rod/earth bar at the earth pit.Even if bare copper conductor were to be used than in no time that too would become ineffective due to oxidation .