Abstract
Load-bearing straw construction emerged in Nebraska (USA) at the end of the 19th century with the invention of the straw-baling machine. Today, this construction method, also known as straw-bale or the Nebraska technique, is of growing interest to self-builders, as well as to professionals aware of the depletion of resources, sensitive to the values associated with eco-construction and keen to promote the use of bio-sourced materials.However, this rediscovery of straw as a constructive solution has yet to be accompanied by an official standard in France. In 2012, the Réseau Français de la Construction Paille published a set of professional rules that serve as a reference, focusing essentially on straw as an insulator and rendered support, listing installation methods and technical details. Beyond that, there are few works qualifying straw as a load-bearing element, and those dealing with the Nebraska technique are even fewer. While experimental studies have been carried out on bales or walls, particularly in compression, those involving complex phenomena such as buckling, creep, relaxation, etc. are virtually non-existent.The aim of the work carried out in this thesis is to lay the foundations for the qualification of load-bearing straw walls as a constructive solution. Using an experimental approach at various scales, from the straw bale to the wall assembled using the Nebraska technique, the various parameters governing short-, medium- and long-term mechanical behavior were characterized: density of the bales, level of prestressing, role of the plaster...To acquire data over long periods, specific experimental devices were developed, coupled with image correlation analysis tools to monitor creep.The initial models derived from these results enable us to propose a design method ensuring the strength and durability of the load-bearing straw construction solution.Over and above the results obtained, this work demonstrates the relevance of this technique as an economic and sustainable alternative to traditional solutions.