Search Results (111)

Robotic timber joinery demands integrated, adaptive methods to compensate for the inherent dimensional variability of wood. We introduce a seamless robotic workflow to enhance the measurement accuracy of the Workpiece Coordinate System (WCS). The approach leverages a Zivid 3D camera mounted in an eye-in-hand configuration on a KUKA industrial robot. The proposed algorithm applies a geometric method that strategically crops the point cloud and fits planes to the workpiece surfaces to define a reference frame, calculate the corresponding transformation between coordinate systems, and measure the cross-section of the workpiece. This enables reliable toolpath generation by dynamically updating WCS and effectively accommodating real-world geometric deviations in timber components. The workflow includes camera-to-robot calibration, point cloud acquisition, robust detection of workpiece features, and precise alignment of the WCS. Experimental validation confirms that the proposed method is efficient and improves milling accuracy. By dynamically identifying the workpiece geometry, the system successfully addresses challenges posed by irregular timber shapes, resulting in higher accuracy for timber joints. This method contributes to advanced manufacturing strategies in robotic timber construction and supports the processing of diverse workpiece geometries, with potential applications in civil engineering for building construction through the precise fabrication of structural timber components. Full article

Exploring the causes of the concave curved form of the roofs in traditional Chinese architecture is key to understanding its unique esthetics and structural logic. Regarding its causes, the academic community offers various explanations, including esthetics and function, but research that delves deeply into specific construction techniques and material limitations and systematically explains how they lead to the precise roof forms is relatively insufficient, which limits our comprehensive understanding of the deep generative logic of this unique form. This study aimed to bridge this gap by systematically exploring the causes of the concave curved form of roofs in traditional Chinese architecture (such as flying eaves, upturned corners, and Ju zhe) from the perspective of construction technology. Through a systematic review of historical literature (especially Yingzao fashi (Treatise on Architectural Methods)); the empirical investigation and analysis of typical architectural examples; detailed research on the structural practices, material properties (especially the creep behavior of timber), and construction techniques of key timber components such as flying rafters, hip rafters, and rafters; and mechanical principles and computational simulation, this study found that the concave curved forms of different parts of the roof, such as the eaves (flying rafters), corners (corner upturn), and main body (Ju zhe), are not purely esthetic choices but are, to a large extent, technical responses or inevitable results stemming from objective construction constraints of the time, including limitations on timber length, component connection methods, structural load distribution, and long-term deformation. Based on these findings, this study proposes the concept of “Passive Form” to summarize this form-generation mechanism, emphasizing that architectural forms are not solely determined by subjective will but are rooted in the adaptation and transformation of real constraints in construction, providing a technical perspective rooted in practice for understanding the forms of Chinese traditional architecture. Full article

This study investigates the hygrothermal performance of window frames to assess their capacity to prevent surface condensation—a critical factor for indoor air quality and building durability, particularly in humid climates. Driven by the practical need to replace existing aluminum frames with more sustainable alternatives, the research evaluates standard aluminum frames against modified timber frames designed to replicate the aluminum geometry. Using daily temperature and humidity data from Valdivia, Chile (2023)—a city with a temperate oceanic and humid climate—interior surface temperatures were simulated with HTflux software and compared against dew point values over a relative humidity (RH) range from 40% to 80%. A novel methodology is proposed for verifying the hygrothermal behavior of window frames based on annual performance analysis and highlighting the need to optimize window design according to specific local climate conditions. The results indicate that modified timber frames exhibited consistently lower average interior surface temperatures (by 1.2 °C) and a significantly higher risk of surface condensation compared to aluminum frames, particularly at typical comfort-level indoor humidity conditions (e.g., 167 vs. 100 condensation days at 50% RH). While both materials presented a high risk of condensation under extreme humidity conditions (80% RH), timber frames showed potentially greater severity of condensation. These findings underscore that the proposed timber frame modification is not hygrothermally adequate without strict control of indoor humidity. Anchored in the Level(s) framework, the study emphasizes the critical influence of geometric design on material performance and advocates for holistic, sustainable construction practices that balance energy efficiency, environmental impact, and occupant comfort. It highlights the need for integrated design solutions and effective moisture management to ensure building resilience in humid environments. Full article

The Life Cycle Assessment (LCA) evaluates the environmental impacts of a product or service throughout its life cycle, from material extraction to end-of-life, considering factors such as global warming, acidification, and toxicity. However, despite its significant health effects, noise has not yet been incorporated into the LCA. This study integrates noise impact into the LCA to assess and compare alternative structural designs for Australian high-rise residential and commercial buildings. Three scenarios were analysed: (1) reinforced concrete frames, (2) hybrid timber designs using engineered wood (e.g., cross-laminated timber and Glulam), and (3) steel-frame structures. The system boundary spans cradle to grave, with a 100-year lifespan. Material quantities were extracted from BIM software 2024 (Revit Architecture) for accuracy. The ReCiPe 2016 method converted inventory data into impact indicators, while noise impact was assessed using Highly Annoyed People (HAP) and Highly Sleep-Deprived People (HSDP). The results show that commercial buildings have more significant environmental impacts than residential structures due to their higher material usage. Steel frames generally exhibit the highest environmental impact, while concrete structures contribute most to noise effects. The total noise-integrated impact ranks as steel > concrete > timber. Additionally, noise accounts for up to 33% of the total impact on densely populated areas but remains negligible in low-population regions. These findings highlight the importance of incorporating noise into the LCA for a more holistic assessment of sustainable building designs. Full article

The Tusi manors in the Yunnan–Tibet region exemplify historical timber-framed architecture that seamlessly blends official and vernacular styles. It integrates the characteristics of ‘distinct regionality’ and ‘convergent ethnic identity’, embodies rich construction wisdom and regional ethnic culture, and serves as ‘living’ material evidence for studying regional architectural craftsmanship. Through field surveys and on-site surveying, primary data were collected to obtain architectural samples and foundational documentation of Tusi manors in the Yunnan–Tibet region. By authenticating their prototypes and integrating regional construction practices, this study analyzed the architectural characteristics of these manors, including settlement mechanisms, site selection principles, courtyard layouts, architectural typologies, spatial configurations, and functional systems from an architectural perspective. Building on this foundation, the study incorporates natural environment and socio-cultural contexts to conduct a multidimensional analysis of these characteristics. It aims to improve awareness of the cultural heritage of regional timber-framed buildings and provide a reference basis for the conservation and inheritance of these historical buildings. Full article

The seismic performance assessment of timber structures and topology optimization have been widely researched in recent years. Furthermore, the use of wood as a construction material has increased due to new sustainability challenges. This research assesses the seismic performance of a topologically optimized timber building located in Concepcion, Chile. The structure is a five-story glulam braced frame, designed following current Chilean standards. The structural configuration was obtained through a topology optimization process using a variation of a soft-kill BESO algorithm implemented in MATLAB R2015a, obtaining topologies with low structural redundancy. For the analysis, a full 3D nonlinear model was prepared using OpenSees (Version 3.7.1), and the nonlinear behavior of the structure was only considered at joints using the backbone curves introduced in ASCE 41-13. Six different study cases were analyzed, varying joint strengths and ductility. The fragility curves were determined from a static pushover analysis (SPO) using SPO2FRAG (V1.1), considering the performance levels established in ASCE 41-13. The seismic hazard of the building’s site is estimated through a probabilistic seismic hazard analysis (PSHA), and the seismic performance of each case is determined by computing the probabilities of exceedance of the considered limit states. Analysis results show that wood braced-frame structures with low structural redundancy (and fewer main joints to dissipate energy), such as those obtained from topology optimization algorithms, exhibit a markedly brittle behavior with almost no displacement ductility. This undesirable behavior does not improve by providing more deformation capacity to this structure’s reduced number of main joints. Currently, the Chilean standard for seismic design requires a unique response modification factor R for wood structures. This research suggests that this requirement should be revisited, specifying different R values depending on the wood structure’s redundancy, considering that its displacement ductility comes almost exclusively from the nonlinear deformation capacity of joints. Full article

The building and construction sector accounts for nearly 40% of global greenhouse gas emissions, with steel-framed buildings being a significant contributor due to high CO₂ emissions during production. To mitigate this issue, integrating Cross-Laminated Timber (CLT) into structural systems has emerged as a sustainable alternative. CLT, known for its carbon sequestration properties, offers an environmentally friendly replacement for reinforced-concrete slabs, particularly when paired with steel structures to enhance material reuse and reduce lifecycle impacts. This study focuses on hybrid systems combining H-shaped steel beams and CLT floor panels connected using high-strength friction bolts. A four-point bending test, simulating a secondary beam, was conducted, demonstrating that the composite effect significantly enhances flexural stiffness and strength. Additionally, a simplified method for evaluating the flexural stiffness and yielding strength of these composite beams, based on material and joint properties, was shown to successfully evaluate the test results. Full article

This study analyses the many different parameters of the in-plane flexibility problem regarding the lateral behaviour of light timber-framed (LTF) wall elements with different types of sheathing material (FPB, OSB, or even reinforced concrete), as well as the thickness of the timber frame elements (internal or external wall elements). The analysis simultaneously considers bending, shear, and timber-to-framing connection flexibility, while assuming stiff-supported wall elements as prescribed by Eurocode 5. Particular emphasis is placed on the sliding deformation between sheathing boards and the timber frame, which can significantly reduce the overall stiffness of LTF wall elements. The influence of fastener spacing (s) on sliding deformation and overall stiffness is comprehensively analysed, as well as the different bending and shear behaviours of the various sheathing materials. The results show that reducing the fastener spacing can significantly improve the stiffness of OSB wall elements, while it is less critical for FPB elements used in mid-rise timber buildings. A comparison of external and internal wall elements revealed a minimal difference in racking stiffness (3.3%) for OSB and FPB specimens, highlighting their comparable performance. The inclusion of RC sheathing on one side of the LTF elements showed significant potential to improve torsional behaviour and in-plane racking stiffness, making it a viable solution for strengthening prefabricated multi-storey timber buildings. These findings provide valuable guidance for optimizing the design of LTF walls, ensuring improved structural performance and extended application possibilities in modern timber construction. Full article

The increase in population and urban migration has incentivized the construction of mid-rise and tall buildings. Despite the incremental rise in vertical construction, there are still investigation gaps related to high-rise buildings, such as carbon emissions and the use of low-carbon materials in tall structures. Timber presents a potential sustainable solution for mid-rise and tall buildings. The history of topics in timber building investigations began with the material characterization of innovation in construction technologies such as cross-laminated timber (CLT) and practical topics like construction collaboration, sustainability, engineering, and construction science. To identify potential topics and understand the research history of mid- and high-rise timber buildings, a bibliometric analysis is proposed. Therefore, this article aims to perform a bibliometric analysis with a science mapping technique to categorize and analyze the evolution of mid- and high-rise timber building research topics and identify the most relevant trends and current challenges. A co-occurrence keyword analysis was performed with the software SciMAT to analyze the evolution and actual trends of mid-rise and tall timber buildings. The results show an evolution in the investigation topics from timber frame elements to mass timber and CLT for high-rise buildings, which was expected due to the higher structural capacity of the mass timber product. Surprisingly, sustainability topics such as carbon emission and life-cycle analysis (LCA) were transversal in all periods with concrete as a recurrent keyword in the analysis. More specialized topics such as robustness, disproportioned collapse, perceptions, and attitude were observed in the final periods. Research projections indicate that for mid-rise and tall timber buildings, the environmental potential has to be aligned with the structural feasibility and perception of the construction’s actors and society to improve the carbon emissions reduction and support the increment of the population in an urban context. Full article

The conducted archival and field research focused on the analysis of details in timber-frame construction in Western Pomerania within the borders of the Republic of Poland. The researcher examined the influence of high architecture on the vernacular architecture of towns and villages in Western Pomerania throughout historical development, specifically on distinct, characteristic building types. In this study, I took into account the impact of local traditions as well as those brought by settlers. The groups of timber-frame structures that were investigated included residential buildings in small towns, rural cottages and farmsteads. The analyzed structures were erected from the second half of the 17th century to the early 20th century. This broad timeframe is explained by the limited number of structures with preserved wooden ornaments in the studied area. Particular attention was given to the relationship between detail and the form of the structure, as well as its impact on the perception of the whole. Full article

Global construction activity remains the least responsive large economic sector to the exigencies of global climate change. The focus has centered on operating emissions of buildings, while upfront embodied emissions in building materials remain unabated. Softwood timber, a commonly used building material, can remove and store atmospheric carbon in buildings for decades. However, the upfront climate benefits of using softwoods in building frames are limited due to the multi-decadal growth and harvest cycles of forest plantations. The objective of this study was to demonstrate that fast-growing Eucalyptus is a superior carbon sequestration feedstock for building materials compared to slow-growing softwoods. We quantified the relative carbon benefits of Eucalyptus to a group of commonly used North American softwoods in an all-carbon-pools, risk-adjusted model that compares the net present value of carbon flows over a 100-year period. Using a novel carbon benefit multiple metric, the analysis shows that short-rotation, high-yield Eucalyptus plantations are 2.7× to 4.6× better at sequestering atmospheric carbon than softwoods, depending on the various risk perception scenarios. The results indicate that building decarbonization can be enhanced by using fast-growing and high-yielding Eucalyptus species plantations. Full article

In timber construction, Glulam post-and-beam systems are commonly used to transfer vertical loads to the foundation. In such systems, the connections play a critical role in structural performance. Pre-engineered connectors, which facilitate fast and efficient assembly, are typically designed to resist only vertical shear loads. However, during seismic and wind events, post-and-beam systems deform horizontally, and axial forces develop at the connections. In this research, the performance of RICON and MEGANT pre-engineered connectors was studied under biaxial loading involving concurrent shear and axial forces. A total of 12 full-scale tests on Glulam frame segments were conducted. Neither type of connector experienced any resistance loss under concurrent shear loads equal to the factored shear resistance and axial loads equal to 5% of the factored shear resistance. The axial load-carrying capacity of the RICON and MEGANT connectors was up to 124% and 97% of their factored shear resistance, respectively. The global failure of all the studied connectors demonstrated both ductility and residual deformation capacity. These results provide valuable information for engineers designing Glulam post-and-beam systems in seismic regions. Full article

The construction sector generates more than one-third of global waste. Although there is a consensus on the need to reduce it, empirical research evaluating current systems to develop circular solutions remains limited. Using a full-scale model, this article evaluates the disassemblability of the corner joint between two prefabricated lightweight timber-framed walls, a system widely adopted in residential construction in North America. The analysis deconstructed the disassembly actions, identified their level of difficulty, and classified the recovered materials into three categories: reusable, recyclable, and waste. The results reveal that the lack of design criteria for disassembly significantly limits the system’s circularity, as it prioritizes assembly speed and energy performance. The predominant use of nails as fasteners complicates the separation of layers, damages materials, and restricts their reuse. This highlights the urgent need to redesign construction solutions that enable efficient disassembly, promote component recovery, and extend their time in circulation. This study establishes a foundation for the evolution of lightweight timber-framed panel design toward systems more aligned with circularity principles. Full article

The widespread adoption of wood in construction is driven by its sustainability, cost-effectiveness, and esthetic appeal. The construction of wood buildings often requires minimal specialized equipment, contributing to affordability and higher demand for wood-frame structures. Wood is considered more sustainable than other building materials, such as steel or concrete, for several reasons, including its renewable nature, low embodied energy, carbon sequestration, energy efficiency, and biodegradability, among others. In the United States, wood is the most common material used in building construction. While many of the structures are single-family homes, wood framing is also prevalent in larger apartment complexes, as well as commercial and industrial buildings. Timber has also been traditionally used for bridge construction, and recently, it has been considered again for the construction of new bridges. Over time, wood-frame construction has developed from a basic method for primitive shelters into a sophisticated field of structural design. As an eco-friendly resource, wood is crucial for promoting sustainable building practices. However, ensuring the long-term performance and safety of timber structures is essential. Regular inspections and testing of wooden structures are important to identify signs of wear, damage, or decay. One type of testing which is gaining popularity is nondestructive testing (NDT). NDT techniques have become invaluable for assessing the condition of timber components because such techniques are non-invasive in nature and do not cause damage, ensuring that structures remain functional with minimal disruptions. These methods provide critical insights into the structural integrity and operational efficiency of wood under sustained loads and in inclement environments. This article examines various NDT techniques used to evaluate timber structures, highlighting their capabilities, as well as advantages and limitations. It also discusses the importance of wood in advancing sustainability within the construction industry and emphasizes the need for accurate and reliable assessment methods to enhance the use of timber as an environmentally friendly building material. By incorporating NDT practices into regular inspection and maintenance protocols for buildings, bridges, and other structures, various stakeholders can ensure the durability, longevity, and safety of timber structures, thereby contributing to the progress and advancement of sustainable construction practices worldwide. Full article

Standard carbon accounting methods and metrics undermine the potential of fast-growing biogenic materials to decarbonize buildings because they ignore the timing of carbon uptake. The consequence is that analyses can indicate that a building material is carbon-neutral when it is not climate-neutral. Here, we investigated the time-dependent effect of using fast-growing fibers in durable construction materials. This study estimated the material stock and flow and associated cradle-to-gate emissions for four residential framing systems in the US: concrete masonry units, light-frame dimensional timber, and two framing systems that incorporate fast-growing fibers (bamboo and Eucalyptus). The carbon flows for these four framing systems were scaled across four adoption scenarios, Business as Usual, Early-Fast, Late-Slow, and Highly Optimistic, ranging from no adoption to the full adoption of fast-growing materials in new construction within 10 years. Dynamic life cycle assessment modeling was used to project the radiative forcing and global temperature change potential. The results show that the adoption of fast-growing biogenic construction materials can significantly reduce the climate impact of new US residential buildings. However, this study also reveals that highly aggressive, immediate adoption is the only way to achieve net climate cooling from residential framing within this century, highlighting the urgent need to change the methods and metrics decision makers use to evaluate building materials. Full article