The international Holcim Awards recognise innovative projects and forward-looking concepts in sustainable construction, regionally and globally. Five target issues by which the Holcim Foundation defines sustainable construction are used as evaluation standards. Three of these target issues are oriented to the concept of an achievement in which social, ecological and economic aspects are in accord. The others relate to contextual and aesthetic impact, innovation and transferability. The BUAS project meets many of these criteria. By aiming to make construction materials more easily available to larger sections of the population, the members of the project team have shown social commitment. The project’s ecological impact comes from using agricultural waste materials and reducing the importation of other building materials. In economic terms, the project team is providing new opportunities to local farmers and makers of wood materials. A naturally occurring adhesive, tannin, is being used innovatively in this project; its use in this context was developed by the BUAS. Last, but not least, the research team is – through this project – transferring technologies that have already been developed in the Western world to an African country that can benefit greatly from using them.
Corn cobs, rice husks and groundnut shells
The prize-winning project deals with turning reusable agricultural resources into structural panels. The project arose out of the idea of building cheap housing in Nigeria. Most buildings in Nigeria are built of cement blocks. The sand and cement mixture has to be imported and is costly, as well as often being of poor quality and durability. As the BUAS has competencies in the areas of architecture, civil engineering and the production of wood materials, the project team under the guidance of Charles Job, professor in the BUAS’s architecture school, aimed to approach the problem of poor quality and relatively expensive building from the fundamentals, and develop new construction materials using locally available resources. Laboratory work was carried out together with partners from Nigerian universities, and was coordinated by Andreas Rosenkranz. He is a student on the international master’s degree course in Wood Technology and an assistant in R&D; he prepared his master’s thesis within this project. As a first step last year, the researchers analysed corn cobs, rice husks and groundnut shells. They investigated ways of turning these into structural panels.
Producing panel material from waste products such as corn cobs or rice is already known and well documented in literature; however, most literature describes trials involving synthetic adhesives. BUAS specialists have been carrying out research for some years on using tannin with conventional wood materials. Tannin is a naturally occurring adhesive that contains little formaldehyde. Using tannin with materials such as corn cobs or rice is new. The first results using corn cobs emerged within three months. The panels were subjected to various tests and compared with the guidelines set out under EN standards for construction materials. The project team is now looking for a partner in Nigeria, so that the product can be introduced there. A prototype house is also planned, to familiarise a wider audience with the potential of the new material. Charles Job would like to involve students in this stage and thus create a connection to the architecture school of the BUAS.
Next steps
The prize ceremony for the Africa and Middle East region opens this year’s cycle of regional Holcim Awards. Prizes will also be awarded by the end of November for the Europe, North America, Latin America and Asia-Pacific regions. The winner of the Global Holcim Awards 2012 will be chosen next year from among the projects from each region to receive an award. The prize money for the Holcim Awards comes to US$ 2 million. The Acknowledgement Prize given to the BUAS project is worth US$ 18,750. The money is to be spent on further research on optimising the construction material and its planned use in Nigeria.