Systèmes constructifs en fabrication additive de matériaux cimentaires

Building systems with additive manufacturing of cementitious materials

• Auteur / Autrice : Romain Duballet
• Direction : Olivier Baverel
• Type : Thèse de doctorat
• Discipline(s) : Structures et Matériaux
• Date : Soutenance le 03/09/2019
• Etablissement(s) : Paris Est
• Ecole(s) doctorale(s) : École doctorale Sciences, Ingénierie et Environnement (Champs-sur-Marne, Seine-et-Marne ; 2010-....)
• Partenaire(s) de recherche : Laboratoire : Laboratoire Navier (Paris-Est) - Laboratoire Navier / navier umr 8205 - Laboratoire Navier / NAVIER UMR 8205
• Jury : Président / Présidente : Jean-François Caron
• Jury : Examinateurs / Examinatrices : Olivier Baverel, Antonella Mastrorilli, Theo Salet, Justin Dirreberger, John Orr, Arnaud Perrot, Arnaud Delaplace
• Jury : Rapporteur / Rapporteuse : Antonella Mastrorilli, Theo Salet

Mots clés

Mots clés contrôlés

Construction en béton

Impression 3D

Béton -- Additifs

Béton

Mots clés libres

Construction additive

Mécanique des structures

Impression béton

Additive Manufacturing

Structural mechanics

Concrete printing

Résumé

Il s'agit de concevoir des éléments constructifs en matériaux cimentaires en fabrication additive grande échelle. La précision géométrique et la liberté formelle apportées par le procédé d'impression 3D de pâtes de ciment à propriétés variables permet d'envisager une architecture interne de l'ordre du centimètre pour des éléments constructifs à grande échelle (typiquement de l'ordre du mètre). Pour cela il convient d'établir des cahiers des charges pertinents pour ces éléments, au regard des possibilités constructives (procédé), des propriétés atteignables (mécanique, thermique, acoustique) et de l'intérêt qu'ils peuvent présenter à un niveau architectural et industriel. La première partie du travail porte en particulier sur la conception de parois architecturées, réalisant des performances accrues

This work addresses a particular topic of automation in construction called 3D concrete printing, or additive manufacturing of cementitious materials. It proposes new manufacturing techniques, other than casting or projection, making use of programmed robots to progressively bring the material where it needs to be, without traditional moulds. The associated promises are thus waste reduction, speed and versatility. More precisely we focus on extrusion techniques, they are inspired from a rapid prototyping approach called fused deposition modeling that consists in stacking laces of fresh mortar onto each other to form a three dimensional object.With such a technique, it is possible to ''print'' the walls of a house inside a gantry structure. This is the main idea proposed today, with promises of productivity, speed and labor cost reduction. This gained popularity in the past few years, businesses and academic projects were born all over the world, research being mostly focused on rheology and mortar formulation. The question of actual usage of such techniques is rarely placed at the center of discussion, whereas it is not clear yet how they will penetrate the market, and more importantly which among the many possible printing processes are more suited to be associated with complete building systems.The house printing idea is a direct and metaphoric transposition of the rapid prototyping method to a larger scale. With the current strategies, involving materials with high cement content, printing a single house in the form of straight or slightly curved walls can be seen as an environmental absurdity. To become a real solution to current housing issues, concrete printing has to bring significant innovation. It is not yet clear if productivity increase will be sufficient to do so. However, if new building products, of novel performances, could be made at a reasonable cost with such techniques, they could become a substantial addition to the building industry. The two courses of action are again material composition and geometry. Provided a very ''poor'' material is printable, massive straight wall houses can become competitive. Otherwise, material consumption can be decreased by printing walls with a complex and light internal structure. In chapter 4 we have proposed a potential solution to make lighter space structures for single house walls. Chapter 5 is dedicated to its prototyping.Apart from housing, the other main fields of application for building systems with robotic extrusion are infrastructures and public works. Some bridges have already been built. Specific underground structures have also been printed and installed in France, see figure below. For those sectors, complex geometrical context and specificity of prefabricated objects can account for 3D printing perhaps more easily than for housing. Surface finish and second work can indeed become less crucial, while productivity gains can be easily obtained.This work is divided in four chapters, and goes from theoretical to experimental. In chapter 2 we try to circumscribe our topic, namely robotic extrusion for automation in construction, through a state of the art report and some definition attempts. Many strategies are indeed possible to print cementitious materials, and can greatly differ in terms of physical phenomena at stake in the material or technology. This brings us to the subsequent question of actual building systems based on such printing processes. In chapter 3 we propose a classification method, to explore some possible approaches. The goal of this work is to shift the current discussion from the ''house printing'' approach to a generalized understanding of automated building systems with cementitious extrusion.