A. CABALLERO GONZALEZ and P. SCHUBERT Instilut fur Bauforschung, Aachen

A programme to evaluate different test methods (prENW52 Part 3 and DIN 18555 Part 5) for the initial shear strength was carried out on different types of units, at different moisture contents at the time of laying, with different types of mortar (general purpose, lightweight LM700 and LM1000). The results show that further development of the CEN Standard is necessary to derive appropriate values.