20.500.12556/RUP-22552 Moisture-activated set-recovery of thermo-hydro-mechanically densified hardwood dowels for high-tolerance timber connections Conventional wooden dowel connections in timber structures rely on tight press-fit installation, which requires high insertion forces and often loosens over time due to stress relaxation. This study investigates an alternative approach that exploits the moisture-activated set-recovery of thermo-hydro-mechanically (THM) densified hardwood dowels to enable slip-fit assembly followed by self-tightening in service. To this end, European beech and black poplar were densified radially and tangentially at different compression ratios. They were then evaluated for swelling kinetics, swelling pressure, bending performance, and moisture-activated expansion using in-situ X-ray CT in water at 20 °C and 100 °C. Results show that activation kinetics can be controlled by temperature. Expansion was rapid within minutes in hot water and slower but equivalent in magnitude at room temperature. Beech outperformed poplar, with radial densification at 35 % compression ratio producing a peak swelling pressure of 5.7 MPa and a modulus of rupture of 268 MPa after activation. Poplar generated higher free expansion but significantly lower pressure due to its lower stiffness. Radial densification was consistently more effective than tangential, enhancing both expansion magnitude and pressure generation. Capillary uptake triggered expansion along the dowel length (∼30 mm in 1 h) and produced an elliptical expansion profile. Importantly, mechanical strength was retained post-activation, which confirms structural suitability. These results demonstrate that THM-densified beech dowels can offer a robust self-tightening mechanism, combining low-force installation with durable pressure generation and stable mechanical performance. This provides a viable path toward adhesive-free, metal-free, high-tolerance timber connections. THM densification dowel laminated timber CT scanning zgoščevanje s trifaznim metkom (THM) THM laminiran les z mozniki CT skeniranje true false false Angleški jezik Slovenski jezik Članek v reviji 2026-01-28 09:33:24 2026-01-28 09:33:28 2026-01-29 03:04:56 0000-00-00 00:00:00 2026 0 0 str. 1-15 atricle 145401 Vol. 512 21 Feb. 2026 0000-00-00 Zaloznikova NiDoloceno NiDoloceno 0000-00-00 0000-00-00 2026-01-24 674 0950-0618 10.1016/j.conbuildmat.2026.145401 266384387 RAZ_Han_Lei_2026.pdf RAZ_Han_Lei_2026.pdf 1 3CBAAC9F812004599C5A599C4C71ABDC a6d267ffaba393380d85e79e722a0e3b35bcbfe058f10cbab490d1ae54fab318 3fa8f6d1-fc24-11f0-b092-005056ac49c0 https://repozitorij.upr.si/Dokument.php?lang=slv&id=32807 https://www.sciencedirect.com/science/article/pii/S0950061826003016?ssrnid=5678540&dgcid=SSRN_redirect_SD 1 0a40ee46-fc24-11f0-b092-005056ac49c0 https://repozitorij.upr.si/Dokument.php?lang=slv&id=32806 Inštitut Andrej Marušič 0 0 0