Monotonic testing of single shear-plane CLT-to-CLT joint with hardwood dowels

• Published in: Journal of Building Engineering 2024-07, Vol.88 (C), p.109252, Article 109252
• Main Authors: Vilguts, Aivars, Phillips, Adam R., Jerves, Ruben, Antonopoulos, Chrissi, Griechen, Darrin
• Format: Article
• Language: English
• Subjects: Cross-laminated timber; Hardwood dowels; Single-shear connection; Timber connections; Timber materials; Wooden dowels
• ISSN: 2352-7102; 2352-7102
• DOI: 10.1016/j.jobe.2024.109252

Reducing embodied carbon emissions in buildings and striving for carbon neutrality through sustainable design has become a primary goal in the construction industry. The industry is expanding its use of wood-engineered products, such as cross-laminated timber (CLT) to achieve those sustainability goals. Furthermore, replacing steel fasteners with lower embodied carbon alternatives is gaining increased attention in timber engineering. This paper aims to quantify the mechanical behavior of single shear-plane CLT-to-CLT joints using hardwood dowels. The study includes 154 single shear-plane experimental tests with four different CLT species, two hardwood dowel species, and two dowel diameters. The test specimens were subjected to cyclic and monotonic loading until failure, and mechanical properties such as yielding and ultimate strength, serviceability and yielding stiffness, and ductility were quantified. The hardwood dowel CLT-to-CLT joints demonstrated high strength with up to 10.3 kN (2.3 kips) capacity per dowel and lateral stiffness of up to 5.2 kN/mm (30.8 k/in) per dowel. This strength and stiffness are roughly equivalent to or exceed values for mass timber wood screws, making hardwood dowels a good alternative. In addition, the observed mean ductility of joints ranged from 2.4 to 4.5. Finally, analytical equations for the joints' yielding strength, lateral serviceability stiffness, and yielding stiffness were derived with non-linear regression analysis and validated using the experimental test results. •Comprehensive experimental and analytical analysis of 154 single shear-plane CLT-to-CLT joints with hardwood dowels.•New analytical equations for strength and stiffness of hardwood dowel joints.•Hardwood dowels show complex failure and moderate ductility.•Hardwood dowel joints equal or surpass wood screws joints in strength and lateral stiffness.•Dowel species and diameter significantly affect joint strength and stiffness performance.