Prepared By: Mohammad Aref As-Sufi Ezzudeen Maraie Ahmad Ziyadah .
description
Transcript of Prepared By: Mohammad Aref As-Sufi Ezzudeen Maraie Ahmad Ziyadah .
An-Najah National University
Civil Engineering Department.Rammed Earth
Submitted in partial fulfillment of the requirements for the Degree of B.Sc. in Civil Engineering
Prepared By:
• Mohammad Aref As-Sufi
• Ezzudeen Maraie• Ahmad Ziyadah.
• Supervisors :Dr. Mohammad Gazal & Dr.Isam
Jardaneh
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 properties of soil to be used as rammed earth
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 Principles1) 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.
2) It has a low cost.
3) It is sustainable resource.
4) 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 the necessary work in construction.
• 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 where the third sample was taken from.
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, non-porous surface.
Results of Atterberg limits test
10 1000.0
10.0
20.0
30.0
40.0
50.0
f(x) = − 0.241157556270095 x + 24.5283679745567
LIQUID LIMIT CHART
NO. OF BLOWS
Moi
stur
e Con
tent
(%)
For 0 % cement .LL = 44.6PL = 28.6
PI = LL - PL = 16.1
Results of Atterberg limits test For 2 % cement .
LL = 44.6PL = 35.9
PI = LL - PL = 8.7
10 100
-20.0
-10.0
0.0
10.0
20.0
30.0
40.0
50.0
f(x) = 0.949311161167652 x − 23.193026395923
LIQUID LIMIT CHART
NO. OF BLOWS
Moi
stur
e Con
tent
(%)
Results of Atterberg limits test For 6 % cement .
LL = 44.6PL = 36.1
PI = LL - PL = 8.5
10 1000.0
10.0
20.0
30.0
40.0
50.0
f(x) = 0.118114860176341 x + 13.7460013849448
LIQUID LIMIT CHART
NO. OF BLOWS
Moi
stur
e Con
tent
(%)
Results of Atterberg limits test For 12 % cement .
LL = 44.6PL = 34.4
PI = LL - PL = 10.2
10 1000.0
10.0
20.0
30.0
40.0
50.0
f(x) = − 0.01514628885995 x + 41.9293374094155
LIQUID LIMIT CHART
NO. OF BLOWS
Moi
stur
e Con
tent
(%)
Summary for the Results of Atterberg limits test
Percent of cement to the total Wight
12 %cement
6%cement
2%cement
0%cemen
t
44.6 44.6 44.6 44.6 Liquid Limit
34.4 36.1 35.9 28.6 Plastic Limit
10.2 8.5 8.7 16.1 Plasticity
Index
Results of Unconfined Compression Strength Test
Percent of cement to the total Wight
12 %cement
6%cement
2%cement
0% cemen
t
2week streng
th (kN/m
2)
1week streng
th (kN/m
2)
2weekstreng
th (kN/m
2)
1weekstreng
th (kN/m
2)
2weekstreng
th (kN/m
2)
1weekstreng
th (kN/m
2)
streng
th(kN/m2)
Cube Numb
er
4030 2900 3100 2550 3420 2450 1180 1
3750 2700 3550 2600 3260 2350 1230 2
3890 2800 3325 2575 3340 2400 1205 Average
Results of Unconfined Compression Strength Test
0 2 4 6 8 10 12 140
500
1000
1500
2000
2500
3000
3500
4000
4500
Compressive Strenght vs. % of Cement
1 week2 week
% of Cement
Com
pres
sive
Str
engt
h (k
N/m
2)
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 increases rammed earth gain more strength.
•
Recommendations• Construction of sample elements form
rammed earth such as blocks or walls.
• Testing their strength as whole unit, such as wall, columns or beams
• Inspect their insulation to temperature and acoustics.
• 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.
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