ALTERNATIVE "GREEN" WALL CONSTRUCTION METHODS IN KENYA

The use of conventional construction methods like masonry and brick work has lead to increased environmental degradation. Coupled with the increased cost of these materials, the Kenyan construction industry is now looking for affordable, environmentally friendly wall construction methods. The following are alternatives to the traditional construction technology in Kenya:

Ferrocement:

Sometimes referred to as thin-shell concrete, Ferrocement is a product made from ordinary reinforced with more fibre or steel per meter compared to conventional concrete. This tighter reinforcement translates to increased strength and reduced mixture volume. The fibre rich mixture produces a hard external exterior. Fibers such as jute, flax, cotton and hemp can also be used as a substitute for steel.

Major benefits of ferrocement are: Use of local materials, Lower cost per meter of concrete, flexible design and greater structural strength.

Challenges: The strength of the concrete is dependent on concrete mix, which must be carefully monitored

Soil Stabilized Blocks:

Soil stabilization produces a cost effective, environmentally-friendly masonry wall construction, domes and roofing. Soil stabilized blocks are prepared by mixing earth with a lime or cement stabilizer, and compacting the mix under a 20-40 kg/cm2 pressure, using manual press. Compacting cement/lime stabilized sand creates a strong, dense, even-sized masonry. A single manual press can produce upto 10,000 blocks per month. Now, that’s fast!!!!

Since soil stabilized blocks are sun dried, they have low carbon impact compared to fired clay bricks and its low cost per meter compounds its benefits.

Applications in Kenya:

·         Girls Vocational School (Mbita

·         Youth Generation Center (Kisumu)

·         Boys Vocational School (Mbita)

·         Mamboleo farm (Kisumu)

EarthBag Construction:

As the name suggest, earthbag construction technology uses fabric bags or tubes filled with moist earth (dirt) or rabbles. Polypropylene bags are preferred in this construction method due to their high strength and resistance to rot.

Benefits: the method is “dirt cheap” and uses locally available materials.

Challenges: Keeping the soil at the right consistency and finding the right kind and size of bag.

Application in Kenya: earth-bag construction in Kenya is still in its research stage and no building has been completely done in the country in Earthbag.

Plastic Bottle Construction

Plastic bottle construction is not technically a weight bearing method. The final product is more of a partition wall. There are good insulating properties associated with plastic bottle construction, and the cost is very low. Plastic material, such as bottles and plastic bags, makes up a big part of the rubbish found in the poorer communities in developing countries, Kenya included.

The use of this non-degradable trash is a good start on the path toward providing examples of reusing discarded material. It is also good for bringing a community together to work together on a project.