Prototyping of a Novel Rammed Earth Technology

Abstract

Buildings of the future are called to meet increasingly high-performance requirements and to ensure adequate environmental sustainability of the production and construction chain. This issue has stimulated a keen interest in the use of natural materials in construction. Among these, raw earth has proved to be particularly interesting for its intrinsic availability, sustainability, and recyclability. In Europe, the spread of raw earth building technologies has often been hindered by the lack of specific legislation regulating its use for load-bearing structures, even if in many countries, it can be noticed a widespread and well-established constructive tradition. Some transoceanic research experiences attest that unfired earth can be used, together with different types of reinforcements, to create seismic-resistant buildings. After presenting a review of the main raw earth reinforced technologies, the present study focuses on a novel reinforced and modular rammed earth construction made with natural or recycled materials, developing a technology with low energy consumption and low environmental impact, specifically designed for areas with high seismic risk. In particular, the work presents the results of a prototyping procedure aiming at developing a new seismic-resistant construction system that combines rammed earth with timber reinforcement elements and nylon/polyester ropes. These elements have a dual function: (1) they are fundamental components of the construction process (as they integrate the formwork system), and (2) they act as seismic-resistant devices once the structure is completed. In line with the performance-based approach required by the construction sector, the study aims at defining a controlled and standardised supply chain for rammed earth construction.