Building with earth - Gernot MINKE (1)

15.23
15.24
Bamboo-reinforced rammed earth
walls
A bamboo-reinforced panelled rammed
earth wall technique was developed in 1978
as part of a research project by the BRL,
and successfully implemented jointly with
the Francisco Marroquín University (UFM)
and the Centre for Appropriate Technology
(CEMAT), both in Guatemala (15.25 to
15.29).
In this project, 80-cm-wide and one-storeyhigh
bamboo-reinforced rammed earth elements
were constructed using a T-shaped
metal formwork 80 cm wide, 40 cm high
15.26
15.25
and 14 to 30 cm thick (15.28). The stability
of the wall was provided by four builtin
bamboo rods 2 to 3 cm thick and the
T-shaped section of the wall element. These
elements were fixed at the bottom to a
bamboo ring anchor that was embedded
in the stone masonry plinth, and attached
at the top to a rectangular bamboo ring
anchor.
Due to the rib that was integrated into the
wall element, this element has about four
times stronger resistance against horizontal
forces than a 14 cm wall alone would have
had.
After drying, a 2 cm vertical gap appears
between these elements. This is then packed
with loam. This joint acts as a pre-designed
failure joint, allowing an independent movement
of each element during the earthquake.
This means that these joints can open and
the whole structure can deform (dissipating
seismic kinetic energy) without the wall unit
breaking or falling. The posts on which the
roof rests are located 50 cm away from the
walls (15.27) on the inside, so that the roof
structure is independent of the wall system.
The rammed earth surface was not plastered,
but only smoothed by a trowel and
then painted with a mixture made of one
bag of hydraulic lime, 2 kg common salt,
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Earthquake-resistant building