Compressed Earth Block

Prepared by:Aditya Shah (M.Tech CPM)

Introduction•The new development of earth construction really started in the nineteen fifties, with the technology of the Compressed Stabilized Earth Blocks (CSEB).

•Since then, considerable scientific researches has been carried out by laboratories.

•Since 1960 – 1970, Africa has seen the widest world development for CSEB.

•India developed CSEB technology only in the nineteen eighty’s, but sees today a wider dissemination and development of CSEB.

Earth Architecture in the world an old tradition•Since ages raw earth has been used all over the world as a building material to achieve amazingly long lasting buildings.

•There is hardly any continent or country which does not have numerous examples of earth construction.

Statistics from UNCHS(United Nations Commission on Human Settlements) show that:

40 % of the world population lives in earthen dwellings.

25 % of the world population does not have access to decent housing.

Statistics from the heritage lists of UNESCO show that:

15 % of the “world cultural heritage” is built with earth

25 % of the “world heritage in danger” is built with earth

14 % of the “100 most endangered world heritage” is built with earth

•The oldest earthen building can still be seen in Egypt, near Luxor, which was built around 1300 BC.

•In Saudi Arabia, people were used to build with earth since very ancient times.

What are Compressed Earth Blocks?

Soil!Soil with 12-25%

clay

can be mixed with

sand or sandier

soil to get a

successful mix.

frequently obtained from the ground at

the building

site

How it is made?•The soil, raw or stabilized, for a compressed earth block is slightly moistened, poured into a steel press (with or without stabilizer) and then compressed either with a manual or motorized press.

•The input of soil stabilization has made it possible to build higher with thinner walls, which have a much better compressive strength and water resistance.

What is the difference between stabilized and unstabilized earth blocks?

adding a small

amount of lime and/or

cementGenerally 4-

10%

water resistant

the blocks must be cured for

four weeks after

manufacturing.

Soil suitability and stabilization for CSEB•A soil contains four components: gravel, sand, silt and clay.

•In concrete, the binder of gravel and sand is cement. In a soil, the binder is silt & clay. But silt and clay are not stable in water.

•Thus, the aim of stabilization is to stabilize silt and clay against water, so as to give lasting properties with the minimum of maintenance.

Good soil Gravel 15 % Sand 50 % Silt 15 % Clay 20 %

A good soil for CSEB is more sandy than clayey.

Energy Effectiveness•Producing compressed earth blocks requires about 1% of the energy needed to produce a building brick.

•Only 1 liter of diesel is needed to produce 145 earth blocks, making it an energy-saving production process with minimum CO2 emissions. 

•Building a m² of masonry with CSEB consumes 5 times less energy than a m² of wire cut bricks masonry and 15 times less than country fired bricks!

Ecological comparison of building materials

Energy consumption

4.9 times less than wire cut bricks

15.1 times less than country fired bricks

Pollution emission

2.4 times less than wire cut bricks

7.9 times less than fired bricks

POLLUTION EMISSION (Kg of CO2) PER M3OF WALL

CSEB wall = 56.79 Kg / m3

Kiln Fired Brick (KFB) = 230.06 Kg / m3

Fired Brick (CFB) = 547.30 Kg / m3

Cost effectiveness•Cost is too often limited only to the monetary value. Cubic meter of CSEB is around 30.6 % cheaper than a cubic meter of fired bricks.

Cost Effectiveness•CSEB are generally cheaper than fired bricks

•This will vary from place to place and specially according to the cement cost.

•The cost break down of a 5 % stabilised block will depend on the local context.

Why Compressed Earth Blocks?

Environmentally sound

An adapted material

A local material

A job creation

opportunity

Market opportunit

y

Limiting deforestati

on

Reducing imports

Social acceptance

Cost efficiency

Six production stagesPreparation (Digging

+ Sieving)

Measuring

Mixing (dry + wet)

Pressing

Initial curing and first stacking

Final curing and stacking

2 to 4 people

1 people

1 people

2 people

2 people

3 people

11 to 13 peopleThe details are given for an Auram Press 3000 which can produces 1000 blocks per day

Are these structures strong? YesBoth stabilized and unstabilized CEBs are appropriate for buildings

The durability of a CEB building will allow it to last for centuries! Ancient earthen structures still stand today in many parts of the world.

CEBs have proven to be waterproof, fireproof, bug proof, and with bamboo or rebar reinforcement, these structures can be built to resist earthquake damage in seismic zones. CEBs are an incredible building material.

References•A case study of Compressed stabilized earth block technology, Satprem maini, director of the auroville earth institute.

•www.auroville.com

THANK YOU