InfraStructures - September 2012 - Compressed Earth Blocks Help Build Communities in Third-World Countries

Compressed Earth Blocks Help Build Communities in Third-World Countries

A recent product introduction by Vermeer Corporation has the potential to help address the critical world housing shortage. The Vermeer BP714 Block Press produces compressed earth blocks made from soil with a marginal amount of cement — in some instances 75% less than a cement block — yet has similar strength as a cement block. Compressed earth blocks can be used to build a variety of structures, including homes, schools, churches, clinics and stores.

A Vermeer BP714 block press is used to create a 10.2 cm x 35.6 cm x 17.8 cm compressed earthen block. The mix is made of 95 l of clay-based sandy soil mixed with 7.6 l of Portland cement, then 5.7 l of water is added to the dry ingredients. The block press uses dual compression to form the block. Hydraulic rams first compress the block to provide the uniform dimension as mentioned above. Second, they create cavities that allow areas for seismic reinforcement, roof tie-downs, electrical conduit and plumbing. The second compression provides for uniform density of each block.

“We are able to maintain consistency in dimensions of the compressed earthen blocks, which is critical when you’re trying to compete against the cement block market,” said Terry Butler, operations manager for Vermeer Corporation and the Vermeer Charitable Foundation. “The Vermeer blocks feature a unique interlocking design that does not require any mortar between the blocks when they are stacked, so the construction process may be faster than the conventional masonry method.”

The blocks need to be cured following the production process. Generally, 50 blocks are stacked onto a pallet and wrapped with plastic and allowed to cure and stabilize dimensionally for seven days. Once the cure process is complete, the blocks are ready for building, and after 28 days they become hard as a brick. No firing of the block is required which is an advantage over traditional brick production.

Designed for use in the most remote parts of the globe, the BP714 is built with simple yet reliable hydraulic controls. It does not have any complicated electronic circuitry and the 12.6 hp (9.4 kW) diesel engine features a manual start. The machine can produce three blocks per minute, and provided there is a continuous supply of raw material, the BP714 will produce about 180 blocks per hour.

Source: Vermeer Corporation