Building with earth - Gernot MINKE (1)

Tamped walls
Illustration 10.6 shows the construction of
a building in Pujili, Ecuador, using pumice as
lightweight aggregate mixed in the loam
and lightly tamped into a formwork. The
formwork was immediately dismantled after
the wall was finished. The wall showed a
high degree of strength, although it was still
possible to cut out window openings and
to form sills with a machete, as shown in
10.7.
Poured walls
The easiest way to make a wall of lightweight
mineral loam is to simply pour it into
a formwork (10.9). In this case, the mix was
prepared in a force mixer, shown in 10.8.
With this technique, it is even possible to
use an ordinary cement concrete mixer in
which the loam slurry is poured over the
aggregate while it is being turned (10.11).
Here, the slurry was prepared with an electrically
driven hand mixer, shown in 10.10.
The formwork was simply left open on one
side for the upper portion of the wall, and
the mix was thrown into it and tamped
with a flat piece of timber.
In a two-storey house at Tata, Hungary, a
load-bearing wall of 50 cm thickness was
made with a mixture of loam and expanded
clay. The mixture was poured into the formwork
through a funnel carried by a crane,
a method commonly used in concrete construction
(10.12).
A simple method of reducing expenditures
is to use a lost formwork made of reed on
one or two sides of the wall (10.13).
Illustrations 10.14 to 10.16 show how a lost
textile formwork, designed by the author,
may be used. A piece of fabric maintains its
shape and is stressed by cables fixed to
the timber frame. This gives an idea of the
unlimited variety of creative surface textures.
Pumped walls
For larger projects, especially if there are
firms to make the lightweight mineral loam,
it is advisable to pump the mix into the
formwork with the use of mortar or concrete
pumps. The consistency must be a
10.10
10.11
10.10 Preparing a loam
slurry using an electric
hand mixer
10.11 Mixing of lightweight
mineral loam
using an ordinary concrete
mixer
10.12 Transporting and
pouring lightweight
mineral loam
10.12
10.13
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Tamped lightweight loam