What is rammed earth
Rammed Earth Is a technique for
building walls using raw materials
of earth and other martials such
like clay . It is an ancient
building method that has seen a
revival in recent years as people
seek
more
sustainable
building
materials
and
natural
building
methods.
Aim of the Project
• The main goal of this project is
to
check
whether
the
soil
available in this country can be
used in rammed earth technique or
not.
•
In addition to that the project
found out the optimum percentages
of clay cement mixture that will
give
the
most
appropriate
Rammed Earth History
• Rammed earth technology has been
around for thousands of years,
Real life examples are shown in
the following Figures.
•
Church of the Holy Cross (Episcopal) Stateburg (or Holy
Cross Episcopal Church), built of rammed earth in 1850–1852.
Borough House Plantation (Stateburg, South Carolina).
Indication
• Today more than 30 percent of
the
world's
population
uses
earth as a building material,
Rammed
earth
has
been
used
around the world in a wide range
of climatic conditions, from wet
Northern Europe to dry regions
in Africa. The images below show
some
modern
buildings
using
rammed earth technique.
Rammed Earth Principles
1) Rammed
earth
is
a
simple
construction technique.
2) cement has been the stabilizer of
choice for modern times to be nixed
with earth.
3) After compressing the earth the wall
frames can be immediately removed
and require an extent of warm dry
days after construction to dry and
harden.
4) The structure can take up to two
years to completely cure.
Rammed earth advantages
1) It is widely available.
1) It has a low cost.
2) It is sustainable resource.
1) The construction using earth has
a minimal environmental impact.
Rammed earth advantages
• It viable and suitable for low income
builders .
• Unskilled labor can do most of
necessary work in construction.
the
• Rammed earth has a high thermal mass;
it can absorb heat during the day and
release it at night. This moderates
daily
temperature
variations
and
reduces the need for air conditioning
and heating.
Benefits of Building Using
Rammed Earth
•
•
•
•
•
•
•
Thermal mass
Noise reduction
Low Maintenance
Fire Proof
Rapid Construction
Healthy and Environmentally Friendly
Cost Effective
Laboratory Tests on Soil
• The tests conducted in the lab
were Atterbeg’s limits, which are
liquid limit and plastic limit;.
unconfined compression test was
another important test conducted.
Methodology
• Three sites were suggested to
collect clay soil that will be
checked it is suitability to be
used as rammed earth.
•
Clay
soil
was
mixed
with
percentages of water and cement,
to reach the proper mix that
ensures the suitable properties.
Methodology
• The first sample was taken from
Qarwa Bani Hassan town- Salfeet
area from a place there called "
Jabal
Alimrd",
Picture
below
shows "Jabal Alimard" and the
sampling process.
Methodology
• The second sample was taken from
Beit Wazan town – Nablus area,
the soil was found not suitable.
• The third sample was taken from
down town of Nablus city, from an
area called "Albasateen" the soil
was found to be “clayey with
boulders".
• Picture below shows the place
Atterberg’s Limits
• The Atterberg’s limits are a
basic measure of the nature of a
fine-grained soil. Depending on
the water content of the soil, it
may appear in four states: solid,
semi-solid, plastic and liquid.
In each state the consistency and
behavior of a soil is different
and thus so are its engineering
properties
What is liquid limit?
• The liquid limit (LL) is the
water content at which a soil
changes from plastic to liquid
behavior
Importance of Liquid Limit
test
• The importance of the liquid
limit test is to classify soils.
Different
soils
have
varying
liquid limits.
• Also to find the plasticity
index of a soil you need to know
the liquid limit and the plastic
limit.
Plastic Limit
• The plastic limit is determined by
rolling out a thread of the fine
portion of a soil on a flat, nonporous surface.
Results of Atterberg limits test
For 0 % cement .
LL =
PL =
PI = LL - PL =
44.6
28.6
16.1
LIQUID LIMIT CHART
Moisture Content (%)
50.0
40.0
y = -0.2412x + 24.528
30.0
20.0
10.0
0.0
10
NO. OF BLOWS
100
Results of Atterberg limits test
LL =
PL =
PI = LL - PL =
For 2 % cement .
44.6
35.9
8.7
LIQUID LIMIT CHART
Moisture Content (%)
50.0
40.0
y = 0.9493x - 23.193
30.0
20.0
10.0
0.0
10
100
-10.0
-20.0
NO. OF BLOWS
Results of Atterberg limits test
For 6 % cement .
LL =
PL =
PI = LL - PL =
44.6
36.1
8.5
LIQUID LIMIT CHART
Moisture Content (%)
50.0
40.0
y = 0.1181x + 13.746
30.0
20.0
10.0
0.0
10
100
NO. OF BLOWS
Results of Atterberg limits test
For 12 % cement .
LL =
44.6
PL =
34.4
PI = LL - PL =
10.2
LIQUID LIMIT CHART
y = -0.0151x + 41.929
Moisture Content (%)
50.0
40.0
30.0
20.0
10.0
0.0
10
100
NO. OF BLOWS
Summary for the Results of
Atterberg limits test
Percent of cement to the total Wight
0%
cement
2%
cement
6%
cement
12 %
cement
Liquid
Limit
44.6
44.6
44.6
44.6
Plastic
Limit
28.6
35.9
36.1
34.4
Plasticity
Index
16.1
8.7
8.5
10.2
Results of Unconfined Compression
Strength Test
Percent of cement to the total Wight
0%
cement
2%
cement
6%
cement
12 %
cement
Cube
1week
2week
1week
2week
1week
2week
Number strength strength strength strength strength strength strength
(kN/m2) (kN/m2) (kN/m2) (kN/m2) (kN/m2) (kN/m2) (kN/m2)
1
1180
2450
3420
2550
3100
2900
4030
2
1230
2350
3260
2600
3550
2700
3750
Average
1205
2400
3340
2575
3325
2800
3890
Results of Unconfined Compression
Strength Test
Compressive Strenght vs. % of Cement
4500
4000
Compressive Strength (kN/m2)
3500
3000
2500
1 week
2000
2 week
1500
1000
500
0
0
2
4
6
8
% of Cement
10
12
14
Conclusions
• It can be concluded that the site
Jabal Al-Imrad, presented at good
source of clay soil to be used as
Rammed Earth.
•
(Tests)
was
carried
out
to
figure the most suitable % of
cement to be added to the silty
clay
to
produce
good
rammed
earth. It was found that the most
appropriate % of cement is in
range of 2% .
• Summary of laboratory tests are
as follows:
Conclusions
– Plasticity index decreases with cement
added to the clay soil. However, 2% of
cement is enough for reducing plasticity
index.
– Plastic limit increases as cement is added
to the clay, but the value does not change
with changing % of cement.
– Liquid was found to be unaffected with
quantity of cement.
– Regarding compressive strength it is noted
that as the amount of cement increase the
strength does not increase predominantly.
It seems that 2% of cement by weight would
produce good strength rammed earth.
– In addition to that as time
rammed earth gain more strength.
•
increases
Recommendations
• Construction of sample elements form
rammed earth such as blocks or walls.
• Testing their strength as whole
such as wall, columns or beams
• Inspect their insulation
and acoustics.
to
unit,
temperature
• More places must be checked out locally
to make sure that rammed earth is
feasible at our country. That is to
determine the quantity of clay available.