Strategies in Reuse of Excavated Materials

Abstract

Concrete is the most used construction material in the world. Despite its expeditious implementation and the technical challenges it has addressed thanks to its standardization, it is now showing its limits in terms of environmental impact and the scarcity of natural resources it is composed of. Construction techniques with raw earth, that have long been overlooked because of their time consuming and labor-intensive nature are meanwhile regaining interest. Among these techniques, the ones that reuse excavated soil for which usually landfilling is paid for show now great potential. Sludge for instance, a quarry by- product, can be used as a binder for poured earth. This self-compacting clay concrete offers an alternative to conventional concrete that meets the time and workability constraints of today’s economy and is perfectly adapted to the construction tools and techniques in use. Although the challenges for the development of this technology are for the moment mostly technical, the question arises as to how these new processes could be integrated into current material flows.

This work therefore focuses on the adaptation of the poured earth technique to the en- vironment dictated by the production of gravel and concrete. Potential mixes and their resulting prices are established a material flow analysis designed for gravel production is completed and an Input-Output table is then elaborated based on the data available for material flows in the canton of Zurich and integrating mixes from the material science field. This model aims to take the first steps in investigating the connections between the research and development of poured earth, the production process it would undergo and its overall integration into existing systems.