My journey with African Sky has not stopped since leaving Mali. From there I went to Tierra y Cal in San Miguel de Allende, Mexico to learn more about earth building with the amazing and talented Jim Hallock. At the workshop I had the pleasure of meeting Bernard Amadei (founder of Engineers Without Borders, among other things) and Francesco Piazzesi (founder of ¡Échale! a Tu Casa); two truly inspiring individuals that have done a great deal to make this world a better place. Weeks later I found myself in San Antonio, where I am now working with Jim at Urban Earth to develop, design, and build sustainable CEB buildings in the U.S. and abroad. Education is a big part of what we are doing in Texas, and I am pleased to announce our first building workshop here in San Antonio! This is the place to be if you are interested in sustainable building. Participants get to learn all the details of advanced earthen building by helping construct a 200 square foot home from the ground up! No previous experience required. For further details such as the course syllabus, locations, and accommodations, please visit www.theurbanearthgroup.com, or E-mail us at firstname.lastname@example.org
Despite the bombs falling on northern Mali, bricks are rising near the center of the country at Soumabougou’s almost completed school! In the coming weeks our wonderful construction crew will be attaching the roof, fabricating doors, fastening shutters, and painting walls. Once the chalkboards are hung there will be three rooms simultaneously bustling with ambitious children that have the opportunity to learn in a comfortable environment.
above: the construction team that makes it happen, in front of the school
The upturned blocks above the doors and windows are a modern response to ancient claustra work techniques. Instead of staggering/patterning blocks to create gaps for light and air, we simply turned them on their sides to expose their holes (which also reveals key differences between our CEB’s and unstabilized earth blocks of the past). Perhaps most importantly, this technique reduces tensile forces on the blocks (a factor which commonly causes earth block claustra works to fail).
Our wonderful crew in front of school #1 in Soumabougou! (Looking good Tamba!) I NI CHE! The talented team of Malians has wisely added twelve reinforced concrete columns (castillos) to support the 6 small I-beams (two over each classroom). We also changed the bond beam to run straight across, instead of stepping up the roof slope. Though the holes just beneath the bond beam look like mistakes, they are actually the points where our crew attaches their very clever scaffolding to the building.
Image courtesy of http://colleeninmali.blogspot.com
If you need one more reason to build out of compressed earth block…take a look at my bedroom
The company replacing our sewer system in San Antonio decided that my bedroom would work better as a garage. They had no problem parking a truck inside of it while I was behind the door in the next room. Thankfully, I was the only one inside and the driver was not injured. A structural engineer has confirmed that my little rental house was rocked off its foundation, (it felt like an earthquake!) and it is now slated for demolition. This week I will begin designing a collision-proof replacement made out of earth block…so bring it on Cimarron!
I am happy to report that our first school is going up without a hitch! Though the political situation in Mali remains tense, we have secured the help of a general contractor to oversee the construction process.
On Tuesday, CNN’s “Outfront” covered the conflict in Mali. Though a statement was made that, “…there is no school in Mali.” because of the unrest, I am once again happy to report that the villages we currently serve are less impacted by the recent developments in the north. However, the extended closure of schools in Bamako and throughout Mali’s northern regions comes at a great loss to a still-promising generation of Malians.
Here is a glimpse at the future Ecole Fondamental Du Soumabougou! These are from my rendering process, so expect some polished images in upcoming posts.
Aerial shot of school with opened shutters
The exterior colors suggested by this model are similar to those used on many existing Malian schools. Once we get more acquainted with the building process in Mali, I would like to color each shutter according to a poly rhythm rooted in 2/3 (the root of most African music). The “syncopation” will make each room unique while giving the interior a full range of colored light (which is particularly important in educational architecture).
Most (if not all) of our paints will be mixed on or near the site. Until we become more familiar with the paint-making process in Mali, my palette will be limited.
Light colored interior walls will help attain light levels that are more suitable for a learning environment
Ecole Fondamental Du Soumabougou will be named in honor of Keeth Elementary School in Winter Springs, Florida. Special thanks to the students and teachers there that made this possible!
Elevations with exposed masonry
The plans have arrived in Soumabougou! With my freshly plotted plans and the help of African Sky Executive Director Scott Lacy, ground will be broken on “Ecole Fondamental du Soumabougou” (Keeth Elementary School) any day now.
It feels great to have completed the designs for the first school. I am looking forward to learning from this experience so that the next schools can be even better!
Next month I will be getting my hands dirty at an iCATIS CEB workshop in San Miguel de Allende, Mexico. The course will help me learn and practice basic and moderately advanced techniques of earth block construction that I can pass along to our crew in Mali.
To help bridge the language barrier, I made the plan’s details as visual as possible. A series of pages shows how the blocks are to be laid on each course. A graphic scale based off the module of a block will help our masons by allowing them to easily measure distances by the number of blocks and half-blocks. As an additional aid, Scott translated the block press manual into Bamabara!
Because this is my first time designing and building a school in Mali, I wanted to make sure that there were many blocks leftover. If not used for the building, the extra 1,500+ blocks that I estimate we will have can be used for landscaping (planters, seats, etc.). These exterior features will help create the desired “community doorstep” outside of the school. They will also play vital roles in the school’s functionality by providing shade and mitigating soil erosion (improving air quality).
Coming soon: Fresh updates and images from Soumabougou!
“On March 21, 2012, a coup in Bamako overthrew a democratically elected government. As a result of this coup, various armed groups in the north of Mali have taken over the three regions of Gao, Timbuktu, and Kidal. There are many political implications, but the main concern of African Sky is how to offer Humanitarian support to all Malians in the north, regardless of ethnicity, as they suffer through severe food insecurity and lack of resources for health care.”
At the following link, you can read information from Scott Lacy (Executive Director), Tamba Traore (North Country Director), and Kate Lechner (Managing Director) on how the situation will affect African Sky, and how you can help.
Despite the ongoing conflict, the compressed stabilized earth blocks for our first school have been pressed and are now baking in the sun. Construction of the school is expected to begin on schedule.
In the years to come, architecture will become as important as ever for the people of Mali. For many Malians, this realization is the product of unfortunate circumstances. Within the last week, the Al-Qaeda linked group Ansar-Dine has destroyed seven out out of sixteen ancient shrines in the city of Timbuktu. The remaining nine mausolea are likely to be razed under the power of Ansar-Dine. The destruction of these treasures, which were recently added to UNESCO’s list of world heritage sites, is a great loss to Timbuktu’s long-time residents. Other sacred features, such as a 15th century door at the Sidhi Yahya mosque in Timbuktu (which was only to be opened on the day that the world ends), have been destroyed by Ansar-Dine.
As Mali’s heritage is wounded by the loss of these iconic structures, it becomes increasingly important that we do our best to add to the discourse of Malian architectural history by making functionally and stylistically progressive public buildings that remain sensitive to culture, tradition, and environment.
“Through Compressed Stabilized Earth Block (CSEB), earth architecture has evolved from a traditional craft to a modern technology. This achievement has been (made) possible by taking advantage of the research in laboratories and in the field of many organizations, working all over the world.
Compressed Stabilized Earth Blocks are undoubtedly part of the renaissance of earth architecture which started 50 years ago with Hassan Fathy, the famous Egyptian architect, who promoted adobe (sun dried bricks) and Nubian vaults and domes.” -S. Maini, Auroville Earth Institute, 1996
Test blocks with various soils laying our to dry. The richer orange colors come from the humidity of the soil when pressed.
-“Sophisticated Buildings Will Be Made Out Of Mud”, #1 on Smithsonian’s “40 Things You Need to Know About the Next 40 Years”*
-According to a study by the UNCHS (now UN-Habitat), 40 % of the world population lives in earthen buildings
-One of the oldest know earthen buildings, the Vaults of Ramesseum, near Luxor, Eygpt, dates back to 1300 B.C. The ancient granaries and storehouses adjacent to the temple of Ramesses II have mud-brick vaults that have been standing for over 3,700 years.
The Vaults of Ramesseum
Compressed Stabilized Earth Blocks
By using compressed stabilized earth blocks, we can build schools that are stronger, cheaper, and easier to construct. Most importantly, earth is an abundant resource which can be quarried, pressed, and constructed on-site in Mali. In both Ghana and Mali I have observed many decrepit structures that were recently built by foreigners using foreign materials. Without the means to repair inevitable damages to relatively sophisticated materials, many structures (particularly in urban areas) quickly spiral into disrepair. However, rural areas have fewer abandoned structures because of the vernacular building style, which relies on traditional earth construction techniques and locally available materials.
Our all-Malian construction crew has nearly wrapped up the block making process for our first school in Soumabougou. In January of this year, I got to see them at work as they demonstrated their skills with the new technology (the block press) that African Sky has provided.
In addition to mastering the block press, our friends in Mali now have a great deal of experience composing ideal mixtures of soil, cement, and water in order to make the strongest block possible.
“Green” building is an increasingly relevant and popular topic in the world of architecture. Despite newfound popularity, “green” buildings are rarely as environmentally friendly as we are led to believe. This is because most modern buildings have a great deal of embodied energy, which is the sum of all the energy required to produce goods and/or services. Steel, glass, and concrete require a staggering amount of embodied energy to take shape. This energy accounts for a formidable portion of the world’s carbon dioxide emissions (which is noted as the primary cause of global warming).
Thanks to CSEB technology, we are able to minimize the quantity of cement required to make a formidable block. Cement production alone accounts for 5% of the world’s carbon dioxide emissions, making it a major player in global warming**. Each one of our CSEBs uses approximately 5% cement as a stabilizer. This ratio is two to three times lower than the cement content in most concrete mixtures.
Lime is often used in earth construction as an alternative to a cement stabilizer. However, the manufacturing of lime in a rural context can be difficult and dangerous. Limestone requires a minimum temperature of 898˚ C (1,648˚ F) to oxidize and create calcium oxide (also known as “quicklime”). This temperature far exceeds the capacity of kilns found in the rural villages that we serve.
Instead of mortar, we will use an extremely thin layer of slurry which is similar in composition to the mixture that we use to make the CSEBs. The thinness of this layer consequently reduces the amount of labor and cement required to complete the building.
Our Auram press squeezes the soil, cement, sand, and water with a great deal of pressure to create solid blocks that we use for our buildings. The CSEBs look similar to much more labor-intensive fired clay bricks. Their uniformly sharp edges and interior perforations are a far cry from the crumbly , shovel pressed earth blocks of the past. However, the manufacturing of fired bricks emits 2.4 times more pollution and consumes 4.9 times more energy than CSEBs. The two holes in the middle of our blocks make them substantially lighter than their precedents. It also reduces the amount of material required for each block, which saves time, sweat,and cement. Perhaps most importantly, our block walls can keep the classrooms up to 20 degrees Fahrenheit cooler than one made with concrete walls.
Earth Blocks vs. Compressed Stabilized Earth Blocks
Regular earth blocks are made by casting the soil mixture into molds, packing them by shovel, and then upturning and placing them into rows for sun-baking. The fragile mixtures often crumble as the form is removed from the upturned block. It is highly likely that water will be responsible for returning nearly every earth block back into soil. Small pieces of straw and other organic materials are traditionally incorporated into the mixture to help strengthen the blocks. Ancient vault builders (as well as modern masters of Nubian dome building) used straw to create lighter bricks for their spans. Unfortunately, this weakens the blocks over time as the organic material decomposes. This is a bigger issue in Mali, where termites can expedite the erosion process by feeding off the organic material in the blocks.
When quarrying soil for compressed stabilized earth blocks, we minimize organic material by first removing the topsoil. Our soil tests in Mali proved that the earth in Soumabougou and Dissan was excellent for block-making. By eliminating organic material, we can better ensure the integrity of each CSEB. Proof of the block’s water resistance is in the following video of tests and demonstrations conducted at the Auroville Earth Institute.
**Rosenthal, Elisabeth. “Cement Industry Is at Center of Climate Change Debate.” New York Times 26 October 2007. http://www.nytimes.com/2007/10/26/business/worldbusiness/26cement.html