An overview of the remaining challenges of the RILEM TC 274-TCE, testing and characterisation of earth-based building materials and elements

Antonin Fabbri,Jean-Emmanuel Aubert,Antoine Pelé-Peltier,Domenico Gallipoli,Venkatarama B. V. Reddy,Erwan Hamard,Holur Narayanaswamy Abhilash,Anne Ventura,Quoc-Bao Bui,Jean Claude Morel

doi:10.21809/rilemtechlett.2021.149

Abstract

Based on the RILEM Technical Committee 274-TCE work, this paper is a discussion of the remaining engineering challenges faced by earthen architecture. The assessment of earth material performances requires the development of appropriate procedures and standards. This is discussed in particular for the characterisation, hygrothermal behaviour, mechanical behaviour, and durability of earth materials. One other important challenge, since one of the main advantages classically put forward, is its ecological performance, is a proper assessment of life cycle assessment of earth materials, elements and buildings. Moreover, the paper develops why the approach to earthen construction must be different compared to the dominant construction materials, to preserve its ability to contribute to the ecological transition in the construction sector. In particular, the needs of using local soils, with an architectural approach coping with the limits of the materials, and developing an architectural optimisation to preserve the earthen materials multifunctionality rather than selecting a sole property to be maximised. Lastly, the findings of the paper can be used to develop a holistic approach to earthen construction to foster the development of new earthen architecture projects.

Highlights

Earth is a building material excavated from the subsoil, which can be defined as an accumulation of parent material weathering products and biota degradation products
Rammed Earth appeared during the Iron Age, Compressed Earth Blocks (CEBs) and Light Earth emerged during the 20th century
The reinforced concrete slabs are not recommended for earth buildings in the zones of high seismic risk, due to the high mass and the incompatibility of the stiffness

Summary

Introduction

Earth is a building material excavated from the subsoil, which can be defined as an accumulation of parent material weathering products and biota degradation products. It certainly would be useful to seek solutions with the best environmental performances in a local context, accounting for the nature of the soil, the building’s functional requirements as well as geographical and cultural specificities Such an approach would ensure lower environmental impacts but represents a drastic change in current construction practices. As earthen construction is today, in many countries of the world, a re‐emerging technique, and new professional practices are yet to be established, it seems possible to make this paradigm shift happen This requires the development of numerical tools able to provide optimised environmental solutions according to specific local constraints such as availability and characteristics of local material, usable techniques, or climate. In the current context of the need to substantially reduce building‐related greenhouse gas emissions, there is still strong potential in earth construction techniques for both research and building practice

Discussion and perspectives for future work

Findings

Construction methodology and construction procedure