C.E.B (Compressed Earth Blocks) and C.S.E.B (Compressed Stabilized Earth Blocks)

Earth blocks are unfired, uniform building blocks, compressed with clay-retaining earth. With proper mix design and 4-8% of cement, these blocks meet the required strength.  The sub-soil which contains sand, silt and clay is the most suited to make earth blocks. The blocks can be processed very quickly if the soil conditions are correct. You can make your own earth blocks with a few simple steps –

1. In order to get the best soil for the earth blocks, screen the materials very well. This is time consuming, but ensures a stronger block. The larger debris, stones, gravel, and other matter can be tossed away. The finished pile can be stored for making the earth blocks.
2. Add 4-8% of cement to the finished pile to make the earth block stronger.
3. Add water & sand proportionately to get the correct mix. If the mix has too little water – it can crack the bricks. If the mix has excess water –the bond between sand, clay and cement would be weak.
4. The mix is then put into the required mould and is then compressed. This block is then dried under the sun for about 4 weeks. It then has to be tested for its strength and can then be used for construction.

Sustainability and Environmental friendliness of CEB/CSEB –

1. Earth is abundantly available. Earth dug for foundations can be used to make blocks for that particular structure eliminating transport.
2. It is a labour intensive process & is easily adaptable.
3. Cost and energy efficient material
4. The Earth Blocks are biodegradable
5. Limits deforestation
6. Transferable technology
7. Creates employment
8. Reduces imports and encourages local build
9. Flexible production scale

CSEB blocks are cheaper than fired bricks. Labour is the most expensive in making Earth Blocks. Therefore, if productivity decreases, the cost will increase accordingly. Being produced locally, Earth Blocks are adapted and accepted to various cultural, social habits. The size of the blocks can be chosen as per the mould sizes. However, there are a few limitations of CSEB blocks –

1. Proper soil identification is required.
2. Wide spans are difficult.
3. Low technical performances compared to concrete.
4. Untrained teams produce bad quality Earth Blocks.
5. Bad equipment to make Earth Blocks.
6. Under-stabilizing resulting in bad quality Earth Blocks.
7. Ignorance of basics for production.
8. Unawareness of the correct mix proportions.