The research objectives of this workshop are to establish a global knowledge base for compressed earth block (CEB) technologies, to identify research opportunities exposed by knowledge gaps, to determine interdisciplinary and/or collaborative research opportunities, and to determine accessible methods of communication for research findings. The three-day, hands-on workshop will bring together civil and geotechnical engineering and architecture faculty from around the world to discuss the research objectives in the context of engineering research labs. Particular focus will be given to earthquake resistant design, non-conventional environmental adaptation, and the effects of global climate change on traditional earthen construction. Extensive documentation of the workshop will be developed as a white paper for publication and the information from the workshop will provide the content basis for a new website designed as a living document to receive new information and research.
The world-wide demand for basic shelter has never been greater. CEB construction is characterized by its sustainability, energy efficiency and low cost. By communicating international standards for engineering and design, this workshop will provide real-world benefits for safe and affordable housing. By identifying new research opportunities, this workshop aspires to bring CEB technologies to a broader international audience, especially in developing communities. The findings of this workshop will have an immediate impact. A concurrent workshop, funded by the Bureau of Indian Affairs, will bring together representatives from Native American college construction programs to discuss developing programs in CEB production and construction.
Workshop Overview The objectives of this workshop were to establish a global knowledge base for compressed earth block (CEB) technologies, to identify research opportunities exposed by knowledge gaps, to determine interdisciplinary and/or collaborative research opportunities, and to determine accessible methods of communication for research findings. This three-day hands-on workshop brought together engineering and architecture faculty and practitioners from around the world to discuss the research objectives in the context of engineering research labs. Particular focus was given to earthquake resistant design, non-conventional environmental adaptation, quantitative measurement of energy efficiency, and the expected ramifications of global climate change on traditional earthen construction. The 2007 IPCC report suggests that over 145 million people will be displaced because of climate change in the next 90 years. These people will overwhelmingly be poor. In addition, the report suggests that there will be a dramatic increase of desertification and other changes to ecosystems that will require a complete redefinition of conventional or traditional materials and methods by which developing communities conceive of their built environment. In light of these radical alterations to the biosphere, one obvious option for sheltering the displaced millions will be earthen construction. We had an opportunity in this workshop to explore the implications of global climate change and establish a framework in which the technological needs of the displaced poor can be addressed. The world-wide demand for basic shelter has never been greater. CEB construction is characterized by its sustainability, energy efficiency and low cost. By communicating international standards for engineering and design, this workshop provided participants the opportunity to discuss real-world benefits for safe and affordable housing. By identifying new research opportunities, this workshop brought CEB technologies to a broader international audience, especially in developing communities. The findings of this workshop will have an immediate impact. 1) Health benefits of earth construction. Empirical evidence has shown that earth dwellings can buffer the relative humidity, resulting in a consistent humidity which can be close to 50% in areas where the climate allows this. Other studies have shown that relative humidity ranging between 40 and 60% results in health benefits by limiting the spread of bacteria, fungi, viruses and mites. Tim Padfield working at the Technical University of Denmark has done a lot of work on humidity buffering (mainly for museum archives) and has shown that clay provides the highest buffering capacity of all commonly used construction materials. Using the rich stock of earth buildings in the USA, a study could investigate whether there is a direct correlation between occupant health and earth buildings. 2) Improving the energy efficiency of earth buildings. There are many earth buildings in the USA and with increasing concerns related to energy use, some of these may have to be retrofitted to improve energy efficiency. New earth buildings are constructed with very thick walls, to ensure thermal resistance, but this increases the financial and environmental costs of the buildings. A study could investigate appropriate technology to improve the energy efficiency of both existing and new earth buildings. Techniques used for other forms of construction (such as external insulation which is not vapor permeable) may cause problems as an earth wall has to be "breathable" to allow moisture to move in and out. Inappropriate insulation or inappropriate placement of insulation could result in condensation within the wall structure. 3) An inventory of carbon and energy for the USA. The figures from Hammond and Jones are for the UK and include the embodied energy, embodied carbon dioxide, and the thermal resistance properties of most common construction materials. This information is particularly useful for designers when attempting to minimize energy use in buildings. 4) Given the new NSF/USAID MOU, specific funding that supports field research in developing communities. Countless community development projects, including many CEB and other earthen construction projects, are ongoing and could provide invaluable research data as well as innovative solutions for alternative materials and methods of construction. 5) A major area of discussion throughout the workshop was the need to develop soil characterization methods that would both increase the efficiency and precision of laboratory work and be a foolproof tool in the field for use by non-engineers. In essence, what is sought is a type of litmus test or snapshot that would indicate whether a particular soil sample was safe for construction. 6) While CEB were the focus of this conference, many participants noted that additional research on the structural integrity of assembly systems was largely unknown. Specifically, the connections of CEB to foundation and roof structures where materials other than CEB are used are creating limits for architects and engineers that are interested in CEB for construction in the USA but are limited by the lack of codes and standards.
