NERD Centre develops low cost soil block
 

by Anjana Samarasinghe

The National Engineering Research and Development Centre (NERD) has introduced low cost soil blocks as an alternative wall material for burnt bricks and cement blocks. Chairman of NERD Jayantha Ranatunga said the blocks will be useful since prices of sand has gone up and one cube of sand costs Rs. 4,500 and mining river sand badly affects the environment also.

Our main objective is to introduce low-cost and environmental friendly wall material manufacturing methods for the construction industry.

There is a huge market potential for the cement blocks and we hope new manufacturing methods will attract entrepreneurs to this manufacturing process, he said.

According to the Head of the Civil Engineering Department of NERD Ariyarathne De Silva, these blocks are manufactured with easily extractable soil from lands mixed with cement without adding sand.

Normal cement block manufacturing machines with different modules can be used for the soil block manufacturing. Manual compacting machines also can be used, he said. The strength of the soil block is same as the normal cement block. Strength of the normal cement block should be 1.2N per square metre. If soil blocks are dried in the sun for five days, the strength may be 1.7N per square metre.

The cost of a cement block has increased to Rs. 20 but soil blocks may cost a maximum of Rs 15. Cost of the block may depend on the manufacturing area due to the sufficient soil. In rural areas price of a block may be much cheaper.

"In Northeast areas one cube of sand will be more than Rs. 4,500 but one cube of the soil will be only Rs. 500," de Silva said.

These blocks, can be used for large constructions too, officials said. This method is used in countries like India and Australia.