Métrologie numérique dimensionnelle appliquée à la caractérisation des propriétés hygrothermiques du bois dans la construction

Keywords

Metrology, Hygrothermal Properties, Experimental characterization, Photogrammetry, Wood construction, Numerical Simulation

Subject details

Scientific Context and Challenges: In 2021, the French government identified the renovation and maintenance of buildings as a key sector for civil engineering development over the next 30 years, supported by the 'France Relance' plan. This sector demands innovations in construction materials, particularly wood and wood-derived products, whose thermal and moisture-related properties need better characterization to address challenges linked to energy performance, user comfort, and health. These materials, exposed to various environments, present challenges for precise in-situ measurements, which are crucial for energy flux analysis and performance modeling. Currently, the lack of suitable equipment hinders research in this area, complicating energy renovation and the rehabilitation of old buildings. In-depth research is necessary to develop precise, non-destructive measurement devices adapted to real-world conditions, optimizing material selection and environmental performance of buildings. Research Objectives: The thesis project aims to first improve existing in-situ measurement protocols. Following this step, it will involve designing or enhancing a prototype for measuring thermal and moisture properties on a real-scale building wall, leveraging dimensional digital metrology techniques. The subsequent steps will focus on validating the protocol, measurement system, and associated models. Finally, the experimental device will be applied to create a database of thermal and moisture properties of innovative or unregistered wood-based materials. Research Program and Methodology: The detailed scientific program is structured as follows: 1. State of the Art: Conduct a literature review on current in-situ measurement techniques. 2. Prototyping: Design or improve a device for real-scale measurement of thermal and moisture properties of materials. 3. Experimental Validation: Develop and validate the measurement protocol on representative samples and in real-world settings. 4. Database Development: Build a database of thermal and moisture properties of innovative or unregistered wood-based materials. 5. Practical Applications: Demonstrate the device's utility in practical cases of renovation/rehabilitation or sustainable construction. Expected Contributions: The thesis is expected to provide: 1. Development of an in-situ, non-destructive measurement methodology for thermal and moisture properties of building materials and envelopes. 2. Experimental validation of the developed methods and tools. 3. Creation of a database of thermal and moisture properties for wood-based materials used in construction in France. 4. Application of the measurement method in real-world cases, such as building renovation (reuse or recycling of components and materials) and innovative material projects. 5. Assessment of the impact of in-situ measurements on the accuracy of building energy performance evaluation and environmental impact. These contributions will benefit the local construction sector and have national and international relevance for energy renovation and performance improvement issues. The selected PhD candidate will deliver: • An innovative methodology for non-destructive in-situ measurements. • Validated prototypes and models for material characterization in real conditions. • A unique database of wood-based materials and their thermal and moisture properties. • Insights on environmental and energy impacts measured in renovated buildings. All research findings are expected to be published in scientific journals.