Clay bricks are an excellent construction material for Anam City, given the abundance of clay soil in the area. Today I started developing a proposal for a brick firing kiln with Prof. Adoke, the manager of the under-construction Compressed Stabilized Earth Bricks (CSEB) factory. 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.
One of the outcomes of our planning is that Prof. Adoke will meet with one of his colleagues who operates a brick kiln at Abubakar Tafana Balenwa University in Bauchi to discuss constructing a kiln in Anam City. The prospects are hopeful: the operational and construction knowledge is already available in Nigeria, along with the building expertise through a masonry student of his. This is a significant development for road infrastructure in Anam. Best of all: the kiln can be fired using local organic waste products, e.g. rice husks, which are in abundant supply at the Rice Farmers Mill Cooperative in Otoucha (30 minutes away by boat).
This means the fired clay bricks score multiple points as a sustainable road construction technology:
(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 after the end of the rainy season and flooding cycle.
Images source: “Report on Rice Husk Fired Clay Brick Road Paving, Vietnam,” Bach The Dzung and Robert Petts, available via gTKP.