Three Nordtest methods for testing tensile strength of concrete and bond strength between concrete substructure and cast-on layer of concrete, mortar or sprayed concrete were evaluated in this project for proposing a new revised Nordtest method.
The methods evaluated were NT BUILD 204 - Concrete hardened: Tensile strength of specimens, NT BUILD 351 - Shot Crete, concrete base: Bond strength and NT BUILD 365 - Concrete, repair materials and protective coating: Bond strength, direct pull-off test. These methods have common requirements to the testing equipment.
The testing focused on requirements for the geometrical properties of the test samples, both for laboratory testing as in-situ testing. With some conditions, the suggested method could be used for both type of testing.
A proposal for a revised Nordtest method for replacement of these three abovementioned methods was proposed, and this method is also included in this report.