This is a presentation by Mr. Negasi Zeleke an independent professional at the 3rd Annual East Africa Cement, Concrete and Energy Summit

1. FDRE Ministry of Industry,
Chemical and Construction Input Industry development Institute
And
Addis Ababa University
Addis Ababa Institute of Technology
August 2 , 2018
Project Proposal
on
Compressed Stabilized Earth Block for Appropriate
and Low-Cost Housing for the Rural Area of Ethiopia

2. Background
 Housing is one of the basic needs for human after food and clothing.
 Unfortunately, deficiency of decent housing is a constant problem in many parts
of developing countries, like Ethiopia, where also the population growth is
disproportional to shelter delivery.
 In Ethiopia, adequate shelter is a main problem in most part of the country. And,
soil is widely used in the traditional construction of mud houses called “Chika
bet’’.

3. Ctd…
 The main defects or problems are: walls can easily be eroded by rain and suffer
from extended shrinkage cracks.
 The construction consumes natural resource such as woods, its external and
internal appearance is not much attractive.
 Adequate shelter is one of the most important basic human needs. As per the
data from Central Statistical Agency of Ethiopia, the projected data in 2016 is
73.9 million is living in rural area of Ethiopia and when we consider the
housing condition in this rural area, 65% of the house are made from wood
and mud.

4. TRADITIONAL HOUSING CONSTRUCTION IN
ETHIOPIA
Traditional house construction in Ethiopia are divided Based on Climatic
conditions ,
houses of low lands-Kolla (<1400m);
houses of highlands- Woina Dega (1400-2700m) and
houses of highlands Dega (2700 above sea level).
In Ethiopia soil is used extensively in the traditional construction of mud walls
(Chika) both in the Kolla, Woina Dega and Dega area, especially in the central,
northeast, northwest and in the southern eastern rift valley area of the country.
“Chika” is a mixture of Clay, fine and short straw of the Ethiopian common
cereal,”teff” (Eragroetis Abyssinica) and water.

5. OBJECTIVES OF THE PROJECT
GENERAL OBJECTIVE
Substituting wood by CSEB for least cost housing projects.
SPECIFIC OBJECTIVES
 To do a detail investigation on compressed stabilized earth blocks (CSEB) raw
material and technology.
 To design , manufacture and testing (functionality) of manual operated low cost
and appropriate block molding and pressing machine.
 Investigating and/or Generating a way of disseminating this
technology/machinery for each households/Villages to construct their own
house.
 To test the block and also showing as the block is used for house construction.

6. COMPRESSED STABILIZED EARTH BLOCK
 Compressed stabilized earth block, an improved form of one of the oldest
materials used in building construction.
 Compressed Stabilized Earth Blocks (CSEB) are construction blocks made
from a mixture of soil and a stabilizing agent compressed by different types of
manual or motor-driven press machines.
 Other advantages are faster and easier construction method resulting in the
lesser requirement of skilled labour, good strength, insulation and thermal
properties, less carbon emission and embodied energy in the production phase,
create extremely low level of waste and cause no direct environmental
pollution during the whole life cycle.

7. HISTORICAL BACKGROUND OF COMPRESSED
EARTH BLOCK
Figure: the vaults of Ramesseum (built around 1300 BC)
The oldest one can still be seen in Egypt, near Luxor, which was built around
1300 BC: the vaults of Ramasseum, in the “rest" of the Thebes. It has been built
with adobes, the sun dried mud bricks .

8. Ctd…
India also shows very old earthen buildings, like the Shey Palace in Ladakh,
which was built with adobe in the 17th century. the Tabo monastery in Spiti
Vally, Himachal Pradesh, which was built with rammed earth in 996 AD
Figure: Tabo Monastery, Spiti, HP, India – 996 AD

9. Ctd…
 The compressed earth block is the modern descendent of the moulded earth
block, more commonly known as the adobe block.
 The first machines for compressing earth probably date from the 18th century.
In France, Francois Cointeraux, inventor and fervent advocate of "new pise"
(rammed earth) designed the "crecise", a device derived from a wine-press.
Figure: the first Manual press, Cinvaram

10. Ctd…
 In view of the history of earth construction, the compressed block technique is a new
technique.
Figure: Typical compressed earth blocks
 The input of soil stabilization allowed people to build higher with thinner walls,
which have a much better compressive strength and water resistance.
Figure: Building a CSEB project in USA, Midland Texas in August 2006

11. COMPARATIVE ANALYSIS and BENEFITS OF
CSEB
Properties Compressed Stabilized soil
Blocks
Sun-dried Mud
Block
Burned Clay
Brick
Concrete
Masonry Unit
Interlocking
Compressed
Stabilized Soil
Block
Normal
Compressed
Stabilized Soil
Block
GENERAL INFO
Block
Appearance
Wall
Appearance
(not rendered)
Dimension
( L x W x H ) in
cm
(26.5 x 14 x
10)
(29 x 14 x 11.5)
(25 x 15 x 7) to
(40 x 20 x 15)
(20 x 10 x 10) (40 x 20 x 20)
Weight in Kg 8-10 8-10 5-18 5-18 12-14
Texture
Smooth and
flat
smooth and flat
rough and
powdery
rough and
powdery
coarse and flat
Blocks needed to
make up a sq.m.
35 21 30 10 to 30 10

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PERFORMANCE
Wet
Compressive
Strength (MPa)
1 - 4 1 - 4 0 - 5 0.5 - 6
Thermal
Insulation
(W/m C)
0.8 - 1.4 0.8 - 1.4 0.4 - 0.8 0.7 - 1.3
Density (kg/m3) 1700 - 2200 1700 - 2200 1200 - 1700 1400 - 2400

13. ADVANTAGE OF COMPRESSED STABILIZED
EARTH BLOCKS (CSEB)
• Ideally, the production is made on the site itself or in the nearby area.
 The strength and durability has been proven since half a century
 Firewood is not needed to produce CSEB
 Produced locally, with a natural resource and semi-skilled labour,
almost without transport, it will be definitely cost effective!

14. LIMITATIONS OF COMPRESSED STABILIZED
EARTH BLOCKS (CSEB)
• Proper soil identification is required.
• Wide spans, high & long building are difficult to do.
• Untrained teams producing bad quality products.

15. HOW COMPRESSED STABILIZED EARTH
BLOCKS (CSEB) MADE? THE PROCESS:
• SOIL SELECTION

16. Ctd…
• STABILIZATION & MIX PREPARATION

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• COMPACTION

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• CURING

19. Ctd…
• USING THE BLOCKS
 28 days after manufacture, the blocks are ready to use

20. SOIL STABILIZATION
 Soil stabilization is simply the addition of a chemical treatment in a soil
mix to improve its stability and its engineering properties.
 the pozzolanic reaction between the stabilizer and the soil develops a
bind between the soil molecules and make soil durable for engineering
purposes.
 The input of soil stabilization allowed people to build higher with
thinner walls, which have a much better compressive strength and
water resistance.

21. SOIL STABILIZATION TECHNIQUES
 Cement Stabilization
 Lime Stabilization
 Gypsum Stabilization
 Pozzolanas Stabilization
 Other Stabilizers

22. COST COMPARISON OF CSEB WITH BLOCKS
 for the purpose of this proposal we referred the thesis which is
made by Asmamaw Tadege in the year 2007.
S. No Description
Hollowconcreteblock(HCB)
blocksPerm2Plasteredand
painted(outside&inside)
(Birr)
Hollowconcreteblock(HCB)
blocksPerm2Pointed
(outside&inside)(Birr)
Compressedstabilizedearth
blocks(plasteredinternally)
Perm2(Birr)
Compressedstabilizedearth
blocksPerm2(Birr)
1. Block 74.36 74.36 62.40 62.40
2. Mortar for fixing 21.70 21.70 -- --
3. Plastering 50.00 -- 25.00 --
4. Pointing -- 20.00 -- --
5. Painting 24.00 -- 12.00 --
6. Varnish -- -- 7.00 14.00
7. Labor 34.00 22.00 23.00 15.00
8 . Total walling cost 204.06 138.06 129.40 91.40
9. Percentage 0 -32.35 -36.59 -55.2
Table 2: Comparison of CSEB with Hollow Concrete Blocks per m2 area of wall

23. BENCHMARK VISIT
 We visited HYT (Haileybury Youth Trust) at Jinja, Uganda on January
2018.
 HYT is a UK charity Non-governmental organization (NGO) which
established in 1890, HYT has been working with impoverished young
Ugandans since 2006, equipping them with skills and transforming lives.
HYT work together, building for a brighter future.

24. ACTIVITIES DONE BY HYT

25. Ctd …

26. Some Images that show the experience
sharing during our benchmark visits

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28. Groups on CSEB production site

29. GENERAL PROJECT APPROACH