Textile-reinforced concrete (TRC) sandwich panels with lightweight cores are a promising solution for sustainable and slender building envelopes. However, their structural performance depends strongly on the shear connection between the outer shells. This study investigates the flexural behavior of TRC sandwich panels with glass fiber-reinforced polymer (GFRP) rod connectors under four-point bending. Three full-scale specimens were manufactured with high-performance concrete (HPC) face layers, an expanded polystyrene (EPS) core, and 12 mm GFRP rods as shear connectors. The panels were tested up to failure, with measurements of load–deflection behavior, crack development, and interlayer slip. Additionally, a linear-elastic finite element model was developed to complement the experimental campaign, capturing the global stiffness of the system and providing complementary insight into the internal stress distribution. The experimental results revealed stable load-bearing behavior with ductile post-cracking response. A degree of composite interaction of γ = 0.33 was obtained, indicating partially composite action. Slip measurements confirmed effective shear transfer by the GFRP connectors, while no brittle failure or connector rupture was observed. The numerical analysis confirmed the elastic response observed in the tests and highlighted the key role of the GFRP connectors in coupling the TRC shells, extending the interpretation beyond experimental results. Overall, the study demonstrates the potential of TRC sandwich panels with mechanical connectors as a safe and reliable structural solution.

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This paper presents an experimental investigation of a demountable hybrid timber–carbon-reinforced concrete (CRC) wall system with a reversible mechanical connection detail based on embedded transport anchors, screwed steel angle brackets, and full-thread screws. The study addresses a wall concept in which a thin externally mounted CRC plate contributes to lateral load transfer through discrete reversible connection points rather than through a bonded or cast-in-place composite interface. Four full-scale wall specimens were tested under horizontal shear loading and a nominal vertical preload of $92\mathrm{kN}$ in an adapted in-plane shear test arrangement. The maximum horizontal loads ranged from $19.7$ to $22.7\mathrm{kN}$, with a mean value of $21.2\mathrm{kN}$ and a coefficient of variation of $5.9\%$. For the three specimens with complete displacement records, the head displacement at maximum load ranged from $33.7$ to $45.8\mathrm{mm}$. The initial wall stiffness $K_{0.05-0.15}$ ranged from $1.93$ to $2.80\mathrm{kN}/\mathrm{mm}$, whereas the stiffness evaluated between $0.2F_{\max }$ and $0.4F_{\max }$ ranged from $0.52$ to $0.67\mathrm{kN}/\mathrm{mm}$. Normalized to the reference width of the tested configuration, the maximum horizontal load was $15.8$ to $18.2\mathrm{kN}/\mathrm{m}$. Damage initiated locally in the CRC anchorage zones, especially at the corner anchors, and progressed from first cracking to local concrete spalling. The governing failure mode was local concrete failure in the anchorage zones, accompanied by deformation of the steel angle brackets, while no critical damage was observed in the timber joints. The results demonstrate the feasibility of the investigated reversible timber–CRC connection concept for transferring in-plane shear forces in the tested configuration, but further tests are required before general design recommendations can be derived.

The thermally efficient and lightweight TRC/CLCi composite panels for functional and smart building envelopes, funded by the iclimabuilt project (Grant Agreement no. 952886), offer innovative solutions to sustainably address common failure risks in facade systems. This work specifically emphasizes strategies for mitigating structural, thermal, and fire-related failures through targeted material selection, advanced design methodologies, and rigorous validation protocols. To effectively mitigate structural failures, high-pressure concrete (HPC) reinforced with carbon fibers is utilized, significantly enhancing tensile strength, reducing susceptibility to cracking, and improving overall durability. To counteract thermal bridging—a critical failure mode compromising energy efficiency and structural integrity—the panels employ specially designed glass-fiber reinforced pins connecting HPC outer layers through the cellular lightweight concrete (CLC) insulation core that has a density of around 70 kg/m³ and a thermal conductivity in the range 35 mW/m∙K comparable to those of expanded polystyrene and Rockwool. These connectors ensure effective load transfer and maintain optimal thermal performance. A central focus of the failure mitigation strategy is robust fire behavior. The developed panels undergo rigorous standardized fire tests, achieving an exceptional reaction to fire classification of A2. This outcome confirms that HPC layers maintain structural stability and integrity even under prolonged fire exposure, effectively preventing catastrophic failures and ensuring occupant safety. In conclusion, this work highlights explicit failure mitigation strategies—reinforced concrete materials for structural stability, specialized glass-fiber connectors to prevent thermal bridging, rigorous fire behavior protocols, and comprehensive thermal performance validation—to produce a facade system that is robust, energy-efficient, fire-safe, and sustainable for modern buildings.