Kenya’s construction industry has long relied on concrete as the primary building material due to its durability, strength, and affordability. However, the environmental impact of concrete production including high carbon emissions, the inflexibility of concrete-built designs, and the generally high cost of cement/masonry has increased the desire to find alternatives.
This article explores alternative construction materials that can serve as substitutes for concrete in the Kenyan context.
Building with Compressed Stabilized Earth Blocks (CSEBs)
Compressed Stabilized Earth Blocks (CSEBs) offer an environmentally friendly alternative to concrete in Kenya. Made from locally available soil mixed with a small amount of cement and water, CSEBs are compressed into blocks. They are sustainable, cost-effective, and possess a low carbon footprint. Additionally, CSEBs exhibit durability and good insulation properties, making them suitable for a wide range of construction projects in Kenya.
Utilizing Bamboo for Construction
Bamboo presents an excellent option for construction in Kenya, especially for single-storey residential and rural housing applications. In Kenya, Bamboo is found in the highlands of Timboroa, Mt. Elgon, Uasin Gishu, and Homa Bay counties, just to mention a few places.
As a fast-growing, renewable resource, bamboo offers strength, lightweight properties, and a high strength-to-weight ratio. It can be utilized for flooring, roofing, walls, and decorative elements. Bamboo is also relatively inexpensive and readily available within Kenya, making it a viable alternative to concrete in various construction applications.
Expanded Polystyrene (EPS) Panels
EPS is made from a dense styrofoam panel sandwiched between two layers of galvanized, high-tensile steel mesh wire. The meshed faces are then covered with shotcrete (a special concrete mortar) before being cured normally. The panels can act in both flexure and compression. Thus, they can be used for both load-bearing and non-load-bearing applications, ranging from walls to partitions, and slabs.
A study from the University of Nairobi by Kageni Lilian (2009) showed at the time that while the EPS panels were slightly harder and more expensive to procure than regular masonry, the cost per square meter was reduced by about 15% due to reduced labor costs.
The EPS structures are also faster to build, reducing construction times by nearly half. Thus EPS panels represent a viable alternative to building with concrete and masonry, especially for mass housing projects where the economies of scale for cost reduction can be viably felt.
Use of Timber as a Building Material
While not as popular in Kenya as they are in countries such as Western and Asian countries such as the USA and Japan, timber holds significant potential as a construction material in Kenya. With its renewability and low carbon footprint, Kenya can benefit greatly from building with timber.
Timber exhibits characteristics of lightweight, strength, and good insulation properties. Additionally, timber can be used for decorative purposes, enhancing the aesthetic appeal of structures. However, in Kenya where there is dwindling forest cover, sustainable forest management practices are essential to prevent deforestation and ensure the long-term viability of timber as a building material.
Building with Bricks made from Recycled Plastic Waste
Kenya faces a substantial environmental challenge with its generation of plastic waste. However, this waste can be transformed into bricks made from recycled plastic, offering a sustainable alternative to concrete. A great case study of this in Kenya is the story of Nzambi Matee, whose startup social venture – Gjenge Makers – manufactures about 1500 bricks per day from recycled plastic waste. This venture has also offered employment to dozens of youth from local slum areas.
These bricks possess durability, and good insulation properties, and are relatively easy to manufacture. Moreover, the production process of recycled plastic bricks incurs lower costs, making them a cost-effective solution for construction projects in Kenya.
Conclusion
While concrete has been the dominant building material in Kenya, its environmental impact and cost have prompted the exploration of alternatives. Possible alternatives for concrete in the Kenyan construction industry include Compressed Stabilized Earth Blocks (CSEBs), bamboo, local materials like coral stones and volcanic rocks, timber, and bricks made from recycled plastic waste. By embracing these alternatives, Kenya can foster sustainable construction practices, reduce carbon emissions, create a more resilient built environment, and offer mass housing to the millions of people living in dilapidated conditions.
