Ecomaterials in Low-Cost Housing. Connecting Cutting-Edge Science with the Grassroots

Abstract

The collapse of socialism in Eastern Europe at the end of the 1980s and the ensuing crisis in Cuba also brought about a shift in the country’s housing policies. Large-scale, energy intensive prefabrication plants were phased out in favor of smaller plants where production could be undertaken with far less energy while keeping transport to a minimum. Scientific institutions in the country were called upon to provide solutions to manufacture building materials under these new conditions. In 1993, the Center for Research and Development of Materials and Structures, CIDEM, was integrated in a network of institutions working on development of appropriate technologies for decentralized manufacturing of building materials and innovative methods for construction of low cost housing. This paper illustrates a singular partnership between a Cuban and a Swiss academic institution, engaged in the development and transfer of appropriate technologies for the massive manufacture of environmentally sound building materials (ecomaterials), which are ideal for the socio-economic conditions of most developing countries. High level, fundamental research is done at EPFL; and praxis oriented, applied research is performed in Cuba, in a collaborative effort funded through the SDC-FNS program in Switzerland. The focus of the research is to develop suitable alternatives to partially replace Portland cement with Supplementary Cementitious Materials (SCM) obtained through processing agricultural wastes such as Sugar Cane Straw and Bagasse combined with clayey soils. These materials are subjected to thermal treatment -with a great potential of further using the energy produced- and the resulting ashes can be used as SCMs because of their reactivity. During the first phase of this project (2005–2008), conclusive evidence has been produced on the reactivity of clayey soils studied. In the second phase, the research team developed new interesting possibilities to activate clayey soils to produce high-quality SCMs through a process call “flash calcination”. These results are not only interesting to developing countries, but also to the cement industry in industrialized countries. Both partners have pursued ways of introducing these results with technologies tailored to the conditions of most developing countries, which operate at a scale that in the context of cement manufacture can be considered “small”. CIDEM and the Cuban cement industry are currently negotiating setting up of the first plant in Pontezuela, Cuba, with funding provided by the Cuban cement industry. Through the years of cooperation, CIDEM and LMC have strengthened their links. The partner in the developing country has benefited from accessing first hand, fresh scientific information, also with the opportunity of building up capacity. Both partners have been able to overcome the stumbling blocks along the way of cooperation and this partnership emerges today as a good example of North-South cooperation.