ABSTRACT
At the beginning of the twentieth century, when the first concrete codes were introduced, reinforced concrete construction systems were based on the hierarchical arrangement of linear structural elements. An important break of this concept was the introduction of flat slabs. C.A.P. Turner of Minneapolis developed his “mushroom” system with a strong focus on the construction process (published 1905) implementing the idea of building components. In 1908 Swiss engineer Robert Maillart claimed that these arrangements did not fully reflect the nature of concrete and proposed to let the slab span freely between the columns (patented in 1909). This study asks how the structural components of the new flat slab system can be related to their predecessors, like traditional concepts of a column-beam connection in timber (e.g. bolster) and iron (e.g. haunch) and early reinforced concrete systems. If the Hennebique system in its arrangement does refer to traditional materials, such as iron or timber constructions, what elements and techniques is the mushroom column referring to? The work of the pioneers Turner and Maillart is compared and their differences is discussed in relation to traditional solutions at the crucial point of the connection between the vertical column and the horizontal slab.
