conforming to 'form-active'^7 shapes. Many, for
example, are based on the parabola, which is
the 'form-active' shape for uniformly distrib-
uted gravitational load. They are also shapes
which can be easily described mathematically,
and this makes both their design and their
construction much simpler than those of
equivalent irregular forms such as the chapel
at Ronchamp or the Vitra Design Museum. The
design is simpler because the analysis of the
structure, in which internal forces and stresses
are calculated, is straightforward if the form
can be described mathematically by equations
based on a Cartesian co-ordinate system. The
construction is straightforward when the form
can be described mathematically because this
greatly eases the problem of setting out and
building the formwork on which the concrete is
cast. Thus, the buildings which have been
designed by the architect/engineers fall into
the category of 'true structural high tech' (see
Section 2.2). They perform well when judged by
purely technical criteria concerned with struc-
tural efficiency and 'buildability' in present day
industrialised societies because their shapes
are both 'form-active' and part of the world of
precise mathematical description rather than
of personal preference.
To sum up, the buildings which have been
described above serve to illustrate both the
contribution which reinforced concrete has
made to the development of twentieth-century
architecture and the range of architectural
7 See Appendix 1. forms made possible by the material.^115
Reinforced concrete structures
Fig. 4.19 Plan of the Museum of Decorative Arts,
Frankfurt on Main, Germany, 1979-85. Richard Meier,
architect. Features such as the 3.5° skew which is present
in this plan are readily accommodated by an in situ
reinforced concrete structure. Note that regular column
grids are used where possible as this gives rise to the most
economical forms of construction.
