W. BRAMESHUBER (1), I. BEER (2) and U. SCHMIDT (3)
(1) Director of the Institute of Building Materials Research, RWTH Aachen University
(2) Scientific employee at the Institute of Building Materials Research, RWTH Aachen University
(3) Scientific employee and head of the working group “masonry” at the Institute of Building Materials Research, RWTH Aachen University
It is well known that the test value of the compressive strength of masonry units or elements is influenced by their shape. As this influence is not present in structural masonry, the effect of the shape of the masonry units on their compressive strength has to be considered to ensure a safe design. This is done by using so-called shape factors. With these shape factors the test value of the compressive strength of the units is transformed to the compressive strength of a reference format. In this paper, the European shape factors according to EN 772-1  are described first. Afterwards approaches to describe the dependence of the test value of the compressive strength on the unit shape are given and values from tests conducted in Germany on solid units and elements of autoclaved aerated concrete, calcium silicate and lightweight aggregate concrete are given. The test results are compared with the European shape factors.