Assessing the performance of earth building materials: a review of recent developments

After being almost abandoned at the end of the Second World War, the use of raw earth is currently regaining the interest of architects, engineers and policy makers for the construction of dwellings in industrialised countries. This renaissance is driven by growing ecological awareness and the promotion of construction techniques that minimize energy consumption and carbon emissions. Raw earth displays very interesting thermo-hygro-mechanical properties, which can contribute to the reduction of the environmental impact of buildings not only during construction but also during service life.  Nevertheless, one of the reasons that still prevents dissemination of raw earth into construction practice is the lack of commonly agreed procedures for assessing material performance. The RILEM technical committee TCE 274 has been established as a first step for overcoming this obstacle. The objective of the technical committee is to critically examine current testing procedures in order to propose suitable experimental standards. The results of this work will be presented in future publications while the present paper summarizes the main challenges faced by the committee and briefly describes some of the existing procedures for measuring the engineering properties of earth materials.