Papier Fassaden : Entwicklung konstruktiver Prinzipien für Fassaden aus Papierwerkstoffen mit Fokus auf Brandschutz, Wärmedämmung, Feuchteschutz und ökologische Eigenschaften

Bach, Rebecca; Hildebrand, Linda (Thesis advisor); Knaack, Ulrich (Thesis advisor)

Aachen : RWTH Aachen University (2020, 2021)
Dissertation / PhD Thesis

Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2020


Climate change and the increasing scarcity of resources are decisive for the current developments in the construction industry towards sustainable and energy-efficient building. Paper materials have great potential for use in the construction industry in a closed-loop manner, since they are based on renewable raw materials and have optimized recycling processes so that they can be reused to a large extent as secondary raw materials. The first built projects and basic research demonstrate the suitability of paper materials for structural engineering applications. However, in order for architects, engineers and planners to be able to use paper in everyday construction projects, there is a lack of material data and experience. For this reason, this dissertation develops constructional principles for the use of paper materials in facades or exterior wall constructions, since these have the highest structural-physical requirements. The main question of the thesis is: Which constructionalprinciples are suitable to enable the increased use of paper materials as building materials by architects, engineers and planners? To answer this question, the topics of fire and moisture vulnerability of the material and the resulting building components, as well as thermal insulating and ecological properties, are primarily examined. The thesis is divided into eight chapters. In the first chapter, the introduction is given. Chapter two presents the basics of paper materials in construction such as the history and important material parameters. Chapter three deals with the technical material analyses. The fire protection, thermal insulation, moisture protection and ecological properties of the various paper materials are examined at the material level and placed in the context of conventional building materials. Paper materials with low raw density are highly flammable and may therefore only be used in combination with other materials, coatings or additives. However, they are well suited for thermal insulation functions and water vapor diffusion-open building component layers and are already comparable with conventional building materials. Paper materials with high raw density are comparable to wood-based materials in terms of fire protection due to the formation of a stable char layer when exposed to flame. They are therefore particularly suitable for the load-bearing and outer layers of building components. They are also more impermeable to water vapor diffusion, which must be taken into account in the design of the building. The adhesives used to join the individual paper layers also have a considerable effect on moisture protection. The ecological material properties are comparable to those of wood. Due to the use of the same raw material, the values of the global warming potential as well as the primary energy demand are similar to those of wood and significantly lower than those of most building materials. In terms of raw material requirements, the majority of paper materials have comparatively the best values due to the high proportion of secondary raw materials. In chapter four, the constructive analyses are carried out at the component level. Façade constructions corresponding to the construction typologies: monolithic, layered and skeletal exterior wall construction are designed, dimensioned in terms of building physics, conceptualized in terms of fire protection and ecologically calculated. The functional properties are equated as a basis for comparison in order to compare the resulting paper façade constructions with conventional constructions from an ecological point of view. The result is that paper constructions can be classified ecologically worse than comparable wood constructions, but significantly better than comparable constructions made of conventional building materials. Only the skeleton constructions made of paper materials are better in the overall comparison. In the fifth chapter, the structural implementations and tests of a monolithic, a layered and a skeletal construction are described. The three facades are tested for fire protection, thermal insulation, moisture protection, and deconstruction using building component tests. The fire protection tests illustrate that more research is needed on this topic. Two of the three facades fail the test. Only the monolithic construction adequately withstands flaming. The tests on the thermal insulation properties of the structures confirm the positive results of the material tests. Within the scope of the rain tests, no increase of moisture behind the weather protection layer can be detected. The damage patterns of moisture penetration within the weather protection layer are analyzed and are due to insufficient execution of the coating. The tests for deconstruction also achieve positive results, as only superficial material losses occur due to the separation of the glued layers.Based on the findings of the previous chapters, 16 constructive principles corresponding to the focused issues are derived in the sixth chapter. Important parameters of these principles are the raw density of the materials used, the structure of the component and the coatings or adhesives used. The thesis is closed with a conclusion in the seventh chapter and an outlook on open research topics in the eighth chapter.