The joint shear capacity of a surface is measured by carrying out a shear test on a core taken from a surface. A 100mm diameter core is drilled through a surface or composite beam with the joint forming the diameter of the core and it shall be tested at 7 days and 28 days after grouting. The test procedure shall follow the determination of compressive strength for mortar, it is in accordance with BS EN 1015-11:1999.