European Commission logo
English English
CORDIS - EU research results
CORDIS

DOVETAILED MASSIVE WOOD BOARD ELEMENTS FOR MULTI-STORY BUILDINGS

Periodic Reporting for period 1 - DoMWoB (DOVETAILED MASSIVE WOOD BOARD ELEMENTS FOR MULTI-STORY BUILDINGS)

Reporting period: 2021-08-01 to 2023-07-31

Adhesives and metal fasteners play important roles in the composition and connections of engineered wood products (EWPs) in the construction industry. However, due to their petroleum-based nature, adhesives can cause toxic gas emissions, while metal fasteners compromise the end-of-life disposal and reusability of EWPs. These issues adversely affect the sustainable material properties of EWPs. Numerous studies were conducted in the literature on the technological, ecological, social, and economic aspects of EWPs in construction with different construction solutions, but no studies have been conducted to evaluate the technical performance of dovetail wood board elements (DWBEs). DoMWoB focuses on adhesive- and metal fastener-free DWBE as sustainable material alternatives for ecologically sensitive engineering solutions.
The emergent emphasis on sustainability and heightened environmental consciousness provides a propitious juncture for the delineation of adhesive- and metal fasteners-free pristine wood solutions. These solutions present attributes that distinctly position them as the preferred choice for ecologically conscious construction, thereby amplifying the scope to markedly augment the market share of these offerings while concurrently invigorating the vitality of our wooded domains. Ergo, from the perspective of economic sustainability, the adoption of dovetail concept proffers a conduit for sustained economic expansion devoid of detrimental ramifications on the societal, environmental, and cultural fabric. Equally compelling is its contribution to social sustainability, where environments conceived through DWBE integration substantiate the generation of sustainable and thriving spaces, fostering well-being by astutely comprehending the intrinsic requisites of the occupants' residential and occupational milieus.
DoMWoB is geared towards enhancing the competitive standing of sizeable wooden construction ventures within Finland and the broader European Union, particularly within regional contexts. It also aspires to foster the generation of elevated value-added prospects in line with the principles of the circular economy. These pursuits are aligned with the overarching objectives of European climate policy, while concurrently contributing to the advancement of the bio-economy and sustainable developmental paradigms.
In pursuit of this objective, the focal strategy encompasses the advancement of DoMWoB to secure a formidable global presence, serving as a substitute for established EWPs like CLT. This ambition is predicated upon the cultivation of unwavering assurance in the technical efficacy and congruence of DWBE, a feat facilitated through synergistic endeavors spanning the multifaceted domains of architecture, structural engineering, and building physics. This trajectory delineates a strategic blueprint marked by the delineation of pivotal objectives, including designing, building, testing, culminating in the incisive appraisal of DWBE's market feasibility through a comprehensive market research initiative.
During the 2-year project, a comprehensive array of activities unfolded. These activities encompassed the design, fabrication, and testing of DWBEs in a multifaceted evaluative framework. The assessment spanned domains such as fire performance, the efficacy of airborne sound insulation, bending characteristics, and air permeance attributes. This concerted effort was meticulously orchestrated to position DWBEs as an internationally viable alternative to conventional EWPs.
An experimental investigation was conducted to comparatively evaluate the fire and charring performance of CLT and DMWE. Test specimens, possessing dimensions of 200 mm in thickness, 950 mm in width, and 950 mm in length, were prepared in accordance with the provisions outlined in EN 1363-1. The charring performance of DMWE was found to be very similar to solid timber, while CLT specimens had a clear increase in the charring rate value due to the char fall-off of the first lamellae layer.
A comparative test was conducted according to ISO 140-3 standards to examine the airborne sound insulation capacities of both DMWE and CLT test specimens of 200 mm thickness, 1160 mm width and 1190 mm. The results highlighted the enhanced airborne sound insulation performance of DMWE (43 dB) compared to CLT (40 dB).
Comparative bending tests were performed with test specimens 200 mm thick, 1450 mm wide and 5075 mm long for both CLT and differently configured DMWEs (5-ply, doweled and 3-ply versions). These configurations did not exhibit the desired bending capacity and the design needed to be revised and improved. The new design was tested in September 2023 and promising results were obtained, with the aim of applying for a patent.
An air permeance study on 3 DMWE variations, following Finnish building code guidelines, under certain moisture content conditions was performed. The dimensions of the smallest test sample were 200 mm x 1160 mm x 1160 mm. When DMWE was exposed to dry conditions such as winter, it experienced shrinkage, leading to an expansion of joint gaps and subsequently. Conversely, in conditions with higher humidity levels, the air permeance of DMWE complied with the Finnish building code.
In the long term, it is planned to use sustainable timber for DWBE, where the timber is harvested responsibly from sustainable forests that are constantly renewed and well managed without harming the surrounding environment or native flora and fauna. Due to this aspect of the research and the absence of adhesives and metal fasteners, it will be ensured that services and resources of current and future generations are met without affecting the health of the ecosystems that provide them, in terms of environmental sustainability. A growing emphasis on sustainability and environmental awareness is providing an opportunity for adhesives- and metal fasteners-free pure wood solutions to demonstrate attributes that clearly make it a preferred green building material and thus advance the potential to significantly increase the market share for these products and enhance the vitality of our forests. So, in terms of economic sustainability, DoMWoB practices will support long-term economic growth without negatively impacting the social, environmental, and cultural aspects of the community. In terms of social sustainability, spaces designed with DWBE will contribute to the process of creating sustainable, successful spaces that promote well-being by understanding what people need from where they live and work.
DoMWoB can make significant contributions to the environment, well-being, and the protection of human health, and will provide a human-oriented production model and user comfort, especially due to its adhesive-free structure. Thanks to its natural and pure composition, as a building material, the dovetail solution is particularly suitable for healthcare facilities, kindergartens, and schools, as well as for earthquake zones, due to its particularly robust and flexible connections. Thus, the solution contributes in many ways to people's health and survival in crises. The process of learning the original manufacturing technique of the dovetail concept, which will mediate the green transition in the engineered wood product industry, will contribute to upskilling and reskilling activities as an essential part of a healthy workplace and ultimately healthy people.
DoMWoB image