I agree, this technology has been around already for quite a while, including the "Lego" type shape, I think the most common name is CEB, Compressed Earth Blocks.

Here some info I found in our archives (page 19f):
Skat Building Material Leaflets
and on the gate website:
GATE: COMPRESSED EARTH BLOCKS: MANUAL OF PRODUCTION
GATE: COMPRESSED EARTH BLOCKS: MANUAL OF DESIGN AND CONSTRUCTION

As far as I know, CEBs not really rely on additives like cement or others, they can produced from soil only, or with stabilisers that are more easily available locally like lime or clay. However, typically CEB's are not suitable when exposed to permanent humidity, like as lineing for a latrine pit. So I also assume the research project aims at materials for the superstructure.
Would be interesting to hear some more details on what exactly the research focusses and what the function of these bio-composties are.

Cheers, Florian

The videos you posted are about interlocking stabilized-soil-bricks, a technique also relatively popular here in East Africa that uses regular cement and a compression machine to make the bricks.


www.builditinternational.org/stabilised-soil-blocks

The problem with them is that the compression machine is relatively expensive and difficult to transport, and cement needs cash to buy (besides being also energy intensive to produce). Due to that, the regular kiln burned red bricks are still vastly more popular (and cause together with charcoal huge deforestation problems here in Uganda).

The here proposed plastic bricks, while also questionable in regards to the use of "food" (starch) and the probably also a bit difficult to source glycerin, might be an interesting alternative. The resulting material should actually be quite similar to termite nests (which also use an organic adhesive).

However I very much doubt that they will last very long (see abandoned termite nests), as the TPS (termoplastic starch) is very susceptible to bacterial brakedown under moist conditions (and the glycerin actually attracts moisture from the air).

Edit: Iron or Calcium-Carbonate based bio-grouting techniques are probably more promising for soil-stabilization and thus brick making.

The bricks are used probably like demonstrated
in this video




and prepared in this way


The research is probably on the composition of how to get the bricks really resistance. I tried them out (wanted to build a house with them). They are quite "ecological"

Yours

Christoph

It's not quite clear from the text, but I assume this is meant for the super-structure and not pit-lining?

Did the Brazilian tests give you any good data on the durability in a moist environment? I assume ants could be quite a problem too.

It's a nice idea otherwise, I had thought about it before, basically as part of an artisan small scale bio-diesel production chain, which produces glycerin as a waste-product.

P.S.:

Hi everyone!
Here is an introduction to Antonio Avila’s project which involves the development of building blocks from biocomposites to replace conventional brick and cement constructions for pit latrines.

Grant Title: Lego-like bricks made of bio-composites for pit latrines: A new solution for an old problem

Name of lead organization: Universidade Federal de Minas Gerais

Primary contact at lead organization: Prof. Antonio Avila

Grantee location: Belo Horizonte – Minas Gerais, Brazil

Developing country where the research is being or will be tested: Brazil and Ethiopia (possible site for large scale test)

Short description of the project
Goal(s): Development of a fully biodegradable brick in the “Lego-like” shape for building pit latrines.

Objectives: Create an easy, low cost and user-friendly technique for building pit latrines .

Start and end date: May 2011 – October 2012

Grant type: Grand Challenges Round 6 from Bill and Melinda Gates Foundation – seed grant

Research or implementation partners: No partners

Links, further readings, results to date: A complete report of the research can be obtained upon request to the project’s PI (Prof. Antonio Avila: This email address is being protected from spambots. You need JavaScript enabled to view it.)

Current state of affairs: If a child can put together two pieces of Lego anyone can do it. So, why not create a fully biodegradable brick (made of bioplastics and soil) to be used in pit latrines? The technology is ready to be used. To be able to disseminate the Lego-like brick, we decided to create an Eco-center in a community school in Brazil. The idea is to teach the students, their parents and the community around the school how to manufacture the Lego-like bricks. At the same time we would like to a sense of community and more important create a conscious ecological way of thinking.

Successes so far: The proof of the concept developed by creating the technology. The technology took into consideration different types of soil (humus, sandy, clay, rocky, etc.) and environmental conditions (amount of daily sun, humidity, temperature variations, etc), so that we develop for each region an individual “recipe”. The estimated cost for each brick is less than US$0.04/brick. It does not require any special condition to manufacture the brick, just mix the bio-plastic and soil compress using a manual press and let it dry under the sun. The technique is easy as 1-2-3.

Main challenges/frustration: The main challenges are the government barriers to implement this new technology. The Ethiopian government for example, did not allow us to do field tests before proof of environmental safety conditions. The bricks are made of soil (excavated from the pit latrine location) and bioplastics (a mix of water, corn-starch, vinegar and glycerin). As it can be noticed none of these components has hazardous components. The Brazilian government allowed us to perform the field tests inside the university land area and at the University’s farm. It was only this year that we were able to create the Eco-center, which is a working in progress.