Formfaktoren für Mauersteine

Shape factors for masonry units.

In compressive tests on masonry units, the height of the test value depends on different factors. Among others, the effect of platen restraint occurring during compression may exert a significant influence on the test value of the compressive strength. The extent of this influence mainly depends on the slenderness of the masonry units. The test value of the compressive strength increases with decreasing slenderness due to the influence exerted by the effect of platen restraint. Thus, when the masonry units are made of the same material, masonry units with a low slenderness yield significantly higher compressive strength values than masonry units with a high slenderness. Further influencing factors are the moisture content and the dimensions of the test specimens. It was the aim of a research project conducted at the Institute of Building Materials research (ibac) of RWTH Aachen University to separately derive defined shape factors for the previously mentioned influencing factors. Test specimens with different ratios of slenderness, moisture contents and dimensions which were taken from autoclaved aerated concrete high precision elements of strength classes 2 and 6 as well as from calcium silicate high precision elements of strength class 20 were examined. The results of these investigations are presented in the present paper.