Sliding friction on waterproofing emebrane

[ktlow1]

I have a concrete retaining wall which is placed on a 50 mm of smooth blinding concrete layer, separated by a 0.25 mm polyethylene membrane. Can anyone help with value of coefficient of friction to be adopted for calculation of sliding resistance?

What about coefficient of friction between concrete and other mediums such as sand, or concrete on concrete?

 

[Ginger]

Based on the figures in BS 5975, limiting friction for concrete to concrete use 0.4, and use the same coefficient for concrete to earth.

For the waterproof membrane I would use ZERO for a coeficcient. The reason for this is that such membranes are often used as slip layers to prevent newly cast concrete sticking to the blinding concrete. This sticking generates large restraint forces and causes early age thermal cracking of the concrete. Therefore, zero would be the logical figure to use (unless site testing has been done to generate some other figure).