Wednesday, July 27, 2011

Work products: Fired Clay Bricks

Today, everyone left to visit Miyata (sp?), a neighboring town. I stayed behind to work on a proposal for a brick firing kiln with Prof. Adoke, the owner of the under-construction Compressed Stabilized Earth Bricks (CSEB) factory.

Sample brick kiln.

Clay bricks are an excellent construction material for Anam City, given the abundance of clay soil in the area. CSEB bricks are compressed clay bricks that are first stabilized with lime and cement to improve its structural properties. The need for these additives is unfortunate, given they are a non-renewable resource, but at least the material demand is significantly less compared to other common building materials in the area, e.g. concrete. These bricks are strong enough to serve as a material for house construction, but they are ill-suited for roads.

Fired clay bricks are similar, in that they are a brick mostly composed of clay. They do not require stabilization, however, because they go through an intense firing process that significantly improves the strength of the brick. In a sense, it trades one input (compression and stabilization) for another (energy heat). They are strong enough to withstand the attrition of vehicular traffic.

Fired clay brick pavement.

I would not pass up the opportunity for a field trip under normal circumstances. Prof. Adoke, however, is leaving on Friday to return home and visit his family. He will meet with one of his colleagues of operates a brick kiln at the university to discuss the possibility to construct a kiln in Anam City. The prospects are hopeful: the operational and construction knowledge is there, along with the building expertise through a masonry student of his. This is a big development for road infrastructure in Anam. Best of all: the kiln can be fired using food waste products, e.g. rice husks, which are in abundant supply in Otoucha. This means the fired clay bricks scores multiple counts of sustainable goodness:

(1) Low technological requirement, meaning local employment opportunities and skills transfer,
(2) Local and abundant material source, i.e. clay, meaning low transportation demand,
(3) Avoids the need for cement, coarse aggregate, and fossil fuels,
(4) Labor-intensive construction process, meaning opportunities to provide employment and avoid diesel-guzzling big rigs,
(5) Substantially lower carbon footprint by avoiding cement and using a food waste product as energy input, and
(6) Offers sufficient durability and capacity to meet transportation demand with minimal maintenance requirements.

The brick laying process.

I look forward to developing this proposal and seeing the pilot kiln project come to fruition. It seems that construction could commence as early as December, if everything proceeds smoothly. (Which, in Nigeria, never happens. Oh well – hope springs eternal.)

Pictures source: "Report on Rice Husk Fired Clay Brick Road Paving, Vietnam," Bach The Dzung and Robert Petts, available via gTKP.

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