Experimental characterisation of the moment-rotation behaviour of beam-beam connections using compressed wood connectors

© 2021 The Authors. The widespread use of energy-intensive metallic connectors and synthetic adhesives in modern timber construction has negative implications for the end-of-life disposal or re-use of the structural timber components. Therefore, it is favourable to substitute metallic connectors and synthetic adhesives with bio-based alternatives such as wood-based connectors. Recent studies have shown that densified or compressed wood (CW) with superior mechanical properties could be suitable for the manufacture of wood-based connectors in the form of CW dowels and CW plates. This study experimentally examines the moment-rotation behaviour of semi-rigid type timber-CW beam-beam connections under pure bending. The study also assesses the suitability of current design rules to predict the moment capacity of timber-CW connections. The comparative study has shown that the moment capacity of the timber-CW connection can be conservatively predicted from the characteristic load-carrying capacity of the connections calculated using the EC 5 strength equations.European Regional Development Fund (ERDF) via Interreg North-West Europe grant 348 “Towards Adhesive Free Timber Buildings - AFTB”

Experimental investigation of the moment-rotation behaviour of beam-column connections produced using compressed wood connectors

Copyright © 2022 The Authors. The use of timber in construction in medium–high rise construction has increased in recent years largely due to the significant innovation in engineered wood products and connection technology coupled with a desire to utilise more environmentally sustainable construction materials. While engineered wood products offer a low-carbon solution to the construction industry, the widespread use of adhesive and metallic fasteners often limits the recyclability of the structural components at the end of life of the structure and it may be beneficial to reduce this where possible. To establish the possibility of an all-wood connection solution, this preliminary study examines a series of beam-column connections designs to evaluate the relative performance of the different designs, which are connected with modified or compressed wood (CW) connectors. The connection designs are formed between glued-laminated beam and column members in the first instance and later examined when connecting dowel-laminated timber (DLT) members. The results show that significant moment capacity and rotational stiffness can be achieved for connections solely connected using CW fasteners. Furthermore, the all-wood solution utilising CW fasteners to connect DLT members has also demonstrated significant moment capacity and rotational stiffness capacity without the use of adhesive and metallic components.Interreg North-West Europe (NWE) funded by the European Regional Development Fund (ERDF) for supporting their project Towards Adhesive Free Timber Buildings (AFTB) - Grant ID: NWE_348

Review of state of the art of dowel laminated timber members and densified wood materials as sustainable engineered wood products for construction and building applications

Copyright © 2019 The Authors. Engineered Wood Products (EWPs) are increasingly being used as construction and building materials. However, the predominant use of petroleum-based adhesives in EWPs contributes to the release of toxic gases (e.g. Volatile Organic Compounds (VOCs) and formaldehyde) which are harmful to the environment. Also, the use of adhesives in EWPs affects their end-of-life disposal, reusability and recyclability. This paper focusses on dowel laminated timber members and densified wood materials, which are adhesive free and sustainable alternatives to commonly used EWPs (e.g. glulam and CLT). The improved mechanical properties and tight fitting due to spring-back of densified wood support their use as sustainable alternatives to hardwood fasteners to overcome their disadvantages such as loss of stiffness over time and dimensional instability. This approach would also contribute to the uptake of dowel laminated timber members and densified wood materials for more diverse and advanced structural applications and subsequently yield both environmental and economic benefits.Interreg North-West Europe (NWE) funded by the European Regional Development Fund (ERDF) supporting the project (Towards Adhesive Free Timber Buildings (AFTB) - 348)

Experimental investigation on the effect of accelerated ageing conditions on the pull-out capacity of compressed wood and hardwood dowel type fasteners

Interreg North-West Europe grant 34

Central Slip Repair using Trans-articular K-wires: A Comparative Study.

Summary: Central slip disruption may lead to PIP joint dysfunction causing significant morbidity. Existing evidence for any specific surgical management of these injuries is limited but does favor early mobilization of the PIP joint.Aim: To assess the functional outcome in a cohort of patients undergoing central slip repair with internal K-wire proximal interphalangeal joint splinting and complete immobilization against those with external splinting only.Methods: A single center retrospective analysis of all patients that underwent operative central slip repair in our institution over a 5-year period. Data were collected via the HIPE database and clinical notes. Data relating to demographics as well as range of motion, total active motion {(TAM) (TAM%)} score, and hand therapy rehabilitation type were analyzed.Results: The study population was n = 44 patients. N = 33 patients were treated without a K-wire and n = 11 treated with a K-wire. There was a male predominance, 81.8% (n = 36). Mean age was 40.4 years. There was no significant difference in the mean TAM achieved at final measurement between the “no K-wire” and the “K-wire” treatment groups [no K-wire 202.1° (standard deviations (SD) 40.0) vs. K-wire 187.4° (SD 28.2), p = 0.208]. The “no K-wire group” achieved a mean TAM % of 78.0 (SD 11.4) and the “K-wire group” achieved a mean TAM % of 72.1 (SD 10.8); no statistically significant difference in mean scores was observed between groups.Conclusion: Our study has shown comparable functional outcomes between those having complete joint immobilization with internal K-wire splinting and those that are externally splinted only following central slip repair