Suggest me bonding material to fill gap between concrete wall & fibre sheet, Bond should be waterproof?

Answer 1

I agree with Mike, however generally with joints it often pays to take further precautions. It really depends on the location of the join ... other possibilities could be using a waterproof crystalline compound (waterproof cement for the join).

Have a look at this example in waterproofing a concrete basement.

http://www.conpro.com.au/application-information/waterproofing-concrete-basements/

Answer 2

Foam Backer rod to fill the gap, clean throughly, silicone based caulk applied to the join to the two materials is thick while the middle is thin to stretch. The cross section will be wasp waisted and the shape will come about naturally from the roundness of the backer rod.