Rammed Earth is well known in our
countries since a very long time. It was used
for building outside fences or in small
houses. In this method, a layer of soil is put
on each other inside a wooden frame and
is rammed with a wooden rammer.
This method has been improved greatly in
Europe and Latin America by using different
rammers, such as the Pneumatic Rammers
and the Vibration Plates. It’s very successful
in big projects due to its low cost and
durability.
The soil suitable for Rammed Earth:
It is very important that the soil used in
Rammed Earth consists of the following
ingredients/ percentages:
– Gravel & Sand: 50-70 %
– Silt: 15-30 %
– Clay: 10-20 %
A soil lab analysis can give us the exact
percentages of the soil ingredients and it is
essential when using this method in big
projects. A simple test can be also applied
(the cigarette method)
The cigarette method:
1. Mix Soil with water to form a thin tube,
its diameter 2 cm and length 20 cm.
2. We put this tube at the edge of a table
and we push it outside and watch the
length of the broken part of this tube.
3. If the length of the broken part is 8-12cm,
this means that the soil consists of the
above percentages and is suitable for
building.
4. If the length of the broken part is less
than 8cm, this means that the soil
consists of high percentage of sand.
5. If the length of the broken part is more
than 12cm, this means that the soil
consists of high percentage of clay.
Specifications of the Frames used in
Rammed Earth:
1. When building with Rammed Earth, we
need durable frames to bear the soil
pressure especially when using the
Pneumatic Rammers.
2. The frames should be light in weight and
easy in handling, fixing and un-fixing to
be able to use it several times.
3. Frame measures:
– Length: 1.50 – 3.00 m
– Height: 0.50 – 1.00 m
– Width: should be wide enough to
enable the mason to stand inside
it to ram the earth.
Ramming:
Foundation: Should be built with red bricks
or natural stones with cement with 30-60 cm
height above the earth level. A layer of
insulation course should be fixed before
starting building with Rammed Earth.
• Soil to be rammed in the wooden frame
in layers of 10cm each.
• It is preferable to ram the soil from
outside to inside the frame.
The edges of the walls should not be sharp
to avoid its quick damage.
Rammers:
There are different kinds of rammers:
1. Manual Rammers: It is a wooden rod
with a heavy metal head. This metal
head can be in circular or square shape
to facilitate this process.
2. Pneumatic Rammers: It works with air
compressors and produce high impact
of frequencies, which help the soil to be
rammed properly and quickly. There are
different kinds of these rammers and
choosing them depends on the project
size.
3. Vibration Plate: This rammer was
improved in Germany by using an
electric motor that wi ll cause an
automatic switch to move back and forth
in the wooden frame and thus ram the
earth without any manual interference.
In Egypt, we implemented Rammed Earth
successfully. Dome and vault were
roofed on the Rammed Earth walls. The
outcome was very beautiful and
harmonic. People and masons admired
that combination. I will not forget when
the masons looked at the Rammed Earth
walls with its structure of layers of Gravel
and Clay, and they said: “It looks like a
mountain, 2000 years old“!
The success of this stage is due to the
support of my dear friend Martin Rauch
from Austria and I’m deeply grateful and
debited to him
