European Standards have been published that cover various aspects of the grouting of tendons, as follows:

BS EN 445:2007, Grout for prestressing tendons. Test methods
BS EN 446:2007, Grout for prestressing tendons. Grouting procedures
BS EN 447:2007, Grout for prestressing tendons. Basic requirements

For further guidance on grouting see TR 72, Durable post-tensioned concrete structures.