375e conférence du Ceres 14 avril 2026 - Applications récentes de solutions mixtes bois-béton

Value of the Information & Strength of the Argument

The presentation provides valuable insights into the practical development and certification of an innovative wood-concrete composite floor system. The speakers present a clear argument for the Bobé system, based on a thorough market analysis and a systematic experimental campaign. They justify the need for a new system by highlighting the drawbacks of existing solutions, such as high cost of metal connectors, complex on-site installation, and thick floor assemblies. The argumentation is solid, supported by experimental data from push-out tests, full-scale bending tests, and long-term creep tests. The speakers also address potential concerns, such as the behavior under fire and the effects of concrete shrinkage, providing evidence that their design mitigates these issues. The presentation is well-structured, with a logical progression from problem identification to solution development and validation.

Scientific Rigor, Source Quality, Title Accuracy

The scientific rigor is high, as the development process follows a systematic approach with experimental validation at each stage. The speakers reference relevant literature and codes, such as the gamma method for composite beams and the French guides for wood-concrete floors. They also compare their results with existing standards, including Eurocode 2 and future Eurocode provisions. The sources are primarily internal test results and industry standards, which are appropriate for this type of applied engineering presentation. The title accurately reflects the content, as the presentation focuses on recent applications and the development of a specific solution. No external sources are cited in the description, but the speakers mention a thesis and ongoing research. The presentation is not a literature review but rather a case study from industry, which is appropriate for a conference of this nature.

The title accurately reflects the content: a conference on recent applications of mixed wood-concrete solutions, with a focus on a specific system (Bobé) and its development and certification.

8/10

The presentation is based on extensive experimental campaigns, including push-out tests, full-scale bending tests, and long-term creep tests, with results compared to analytical methods and codes. The speakers are industry experts with direct involvement in the development and certification of the system. However, the content is largely a case study from a specific company, and some claims (e.g., 20% gain over future Eurocode) are presented without full data disclosure.

Markers derived by PSI from the transcript: the creator did not define chapters.

• 00:00Introduction by Dr. Clémence Nicollet, presenting INGENOVA and the context of the French RE2020 regulation.
• 05:00Rationale for developing wood-concrete floors, including market analysis and identification of drawbacks in existing solutions.
• 10:00Presentation of the Bobé floor system: geometry, components, and advantages (no metal connectors, reduced thickness, wood visible ceiling).
• 15:00Overview of the validation process: structural, fire, acoustic, fabrication, and carbon footprint considerations.
• 20:00Detailed discussion of the notched connection: design, push-out tests, and comparison with metal connectors.
• 30:00Full-scale bending tests: validation of the gamma method, behavior of reinforcement, and failure modes.
• 40:00Long-term behavior: creep and shrinkage tests over three years, comparison with codes, and implications for design.
• 50:00Support details and optimization of connections to reduce costs.
• 1:00:00Fire resistance: hypothesis of concrete-encased timber beam and validation through tests.
• 1:10:00Presentation of three recent projects using wood-concrete solutions, illustrating different technical approaches.

• CSTB (Centre Scientifique et Technique du Bâtiment) — Mentioned as the French certification body for ATEx (Appréciation Technique d'Expérimentation) for innovative construction systems.
• Eurocode 2 — Referenced for concrete design and comparison of creep predictions.
• Future Eurocode for wood-concrete composite structures — Mentioned as the upcoming standard for wood-concrete floors, used for comparison in long-term behavior.

• Eurocode 5: Design of timber structures — Provides design rules for timber structures, including composite members, and is consistent with the gamma method used in the presentation.

• Traditional wood-concrete floors with metal connectors — The presentation argues that metal connectors are costly and less rigid, but some studies may show adequate performance. The claim of 20% gain over future Eurocode is based on their specific tests and may not be universally applicable.