Search Results (189)

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

This paper presents an analysis of the ultimate strength of wooden joints of the structures of ancient wooden ships. The aim is to contribute to the discussion about how joining technology and types of joints contributed to the transition from ‘shell-first’ to ‘frame-first’ construction, of which the latter is still traditional Mediterranean wooden shipbuilding technology. Historically, ship construction has consisted of two main structural types of elements: planking and stiffening. Therefore, two characteristic carvel planking joints and two longitudinal keel joints were selected for analysis. For planking, the joint details of the ship Uluburun (14th c. BC) and the ship Kyrenia (4th c. BC) were chosen, while two different types of scarf joints belonging to the ship Jules-Verne 9 (6th c. BC) and the ship Toulon 2 (1st c. AD) were selected. The capacity, i.e., the ultimate strength of the joint, is compared to the strength of the structure as if there was no joint. The analysis simulates the independent joint loading of each of the six numerical models in bending, tension, and compression until collapse. The results are presented as load-end-shortening curves, and the calculation was performed as a nonlinear FE analysis on solid elements using the LSDYNA explicit solver. Since wood is an anisotropic material, a large number of parameters are needed to describe the wood’s behaviour as realistically as possible. To determine all the necessary mechanical properties of two types of wood structural material, pine and oak, a physical experiment was used where results were compared with numerical calculations. This way, the material models were calibrated and used on the presented joints’ ultimate strength analysis. 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

In order to rationally utilize wood materials, increase wood quality, and mitigate drawbacks, research on industrial techniques for timber protection and preservation is essential on a European and global scale. When high-quality timber enters the market, it offers structures and objects that have considerable added value. This study examines the performance of thermally treated (6 h at 170 °C and 200 °C) softwood species (fir wood) when exposed outdoors and applied on wooden building structures as cladding timber, among other structures. International standards were applied for the characterization of the untreated and thermally treated wooden boards after the treatments in terms of physical, hygroscopic, and surface properties. In contrast, all the boards (of dimensions 390 × 75 × 20 mm in length, width, thickness respectively) were exposed outdoors to direct sunlight and a combination of biotic and abiotic factors for a six-month period to mainly investigate the thermal properties (heat transfer analysis/insulation properties) using a real-time test in situ, as well as to investigate their potential resistance to natural weathering (color, surface roughness, visual inspection, etc.). Heat transfer in the thermally treated wood specimens was found to be much slower than that in the untreated specimens, which, combined with lower hygroscopicity and higher dimensional stability, reveals the high potential of thermally treated wood utilization in outdoor applications, such as cladding, facades, frames, and other outdoor elements. Full article

In the frame of an extended research program dealing with wood shavings and wood sawdust utilization in mortar, thermal conductivity and thermal behavior under various temperatures of mortars containing wood shavings and sawdust as a replacement for a part of the conventional aggregates were studied. Mixes with 0, 30, 50 and 70% replacement of conventional fine limestone aggregates with wood shavings were made. Also, mixes with 0, 10 and 20% replacement of aggregates with wood sawdust were made. The density of fresh concrete and the thermal conductivity of hardened concrete were determined. Thermal conductivity was determined with the guarded hot plate method according to standard ΕΝ 12667:2001. Specimens were also submitted to 100, 200, 300, 400, 500 and 600 °C. Flexural and compressive strength were determined 24 h after thermal strain. Results showed that thermal conductivity decreased when volume replacement increased, both for the use of wood shavings and sawdust, thus improving the thermal properties of mortar. Flexural and compressive strength exponentially decrease as exposure temperature increases. 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

Hybrid building construction, in which the steel frame is filled with modular panels made of wood, is a relatively new technical solution. This type of structure allows the integration of large window surfaces. The aim of this study is to indicate the optimal glazing system, taking into account energy consumption, thermal comfort and economic indicators. A house made using new hybrid technology with an area of 152.4 m², located in Bialystok (Northeastern Poland) and in Kiruna (Northern Sweden), was selected as the reference object. Energy simulations of this building were performed with DesignBuilder v. 6.1.8.021 software. Due to the large format of the glazing, the assessment of the thermal environment was performed using the PMV index. An economic analysis aimed at selecting the optimal type of glazing was carried out. It was based on the most commonly used indicators such as LCC, NPV and IRR. The results of this study indicated that the selection of triple-glazed windows in the reference house reduced energy demand by over 22% for Bialystok and about 24% for Kiruna compared to double-glazed windows. Even greater effects can be achieved by using quadruple-glazed windows, as they provide energy savings of 36% and 39%, respectively, for these locations. The results of the analysis performed for a 2% increase in energy prices showed that triple and quadruple windows had a similar LCC value when the discount rate was lower than 2.5% for the Bialystok site. Quadruple-glazed windows were the best option for the Kiruna site when the discount rate was less than 5%. This research study found that, assuming a stable financial situation and a small increase in energy prices, it is recommended to use triple-glazed windows in the climate of Northeastern Poland. In more severe weather conditions, for example those characteristic of the area of Northern Sweden, quadruple-glazed windows are recommended. 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

This paper is focused on the numerical evaluation of the equivalent damping ratio (EDR) given by a dissipative wood-based roof diaphragm in the seismic retrofitting of single-nave historical churches. In the design phase, the EDR could be a key parameter to select the optimal roof structure configuration, thereby obtaining the maximum energy dissipation. In this way, the roof structure works as a damper to facilitate a box behavior of the structure during the seismic response. The EDR measures the energy dissipated by the nonlinear behavior of the roof’s steel connections and masonry walls during seismic events. In a preliminary retrofitting design phase, an initial implementation of the geometries of the walls and the chosen geometry for the roof is carried out by adopting an equivalent frame model (FEM) with inelastic rotational hinges for the nonlinear properties of the masonry walls and inelastic shear hinges for the nonlinear behavior of the roof’s steel connections. Since, for historical churches, the transversal response under seismic events is the worst situation for the single-nave configuration, the earthquake is applied as transversal accelerograms. In this way, the damped rocking of the perimeter walls due to the dissipative roof diaphragm can be described in terms of a hysteretic variable. By varying the value of the hysteretic variable, possible configurations of the roof diaphragm are tested in the design phase, considering the different shear deformation values of the inelastic hinges of the roof. Under these hypotheses, the EDR is evaluated by performing nonlinear Time History analyses based on the cyclic behavior of the inelastic hinges of the roof, the strain energy contribution due to the walls, and the lateral displacements of the structure. The EDR values obtained with the Time History method are compared with those obtained by applying the Capacity Spectrum Method by performing nonlinear static analyses, either for the coefficient method of FEMA 356 or the equivalent linearization technique of ATC-40. The EDR evaluations are performed by considering the following different hysteretic behaviors of the roof’s steel connections: the skeleton curves with stiffness degradation and the trilinear model with strength and stiffness degradation. Finally, the variation in the EDR values as a function of the hysteretic variable is presented as well so to evaluate if the maximum EDR value corresponds to the optimal value of the hysteretic variable able to reduce the lateral displacements and to contain the shear forces acting on the roof and the façade under a safety limit. Full article

Building materials, including polyvinyl chloride (PVC), play a key role in construction engineering, influencing the durability, esthetics, and functionality of structures. PVC stands out for its lightness, thermal insulation, and corrosion resistance. This makes it competitive with wood, aluminum, or steel, particularly in the manufacture of window joinery. One of the key technological processes in the processing of PVC profiles is welding, the quality of which depends on the precise control of parameters such as the temperature, time, and pressure regulating the speed of the welding heads. In modern welding machines, the use of servo drives guarantees the adequate precision and repeatability of the process, which allows better adjustment to technological requirements than in older machines. This study aimed to determine the effect of the heating head feed rate for selected milling depths on the quality and strength of window frame welds. A criterion in the assessment of the strength of the window frames was the result of failure load tests on the welds. In addition, the tests took into account the quality of the welds. The tests showed that the welding head feed rate of 0.25 mm/s generated the highest-quality welds, taking into account the continuity and symmetry of the weld and its highest failure load. When milling the composite to a depth of 1 mm, the average value of the failure load was 3637 N. Meanwhile, for speeds of 0.19 mm/s and 0.31 mm/s, it was 3157 N and 3033 N, respectively. For the 0.5 mm milling variant and without milling the composite, the average load values were significantly smaller. Full article

This study evaluates the carbon footprint of three bio-concrete families—wood (WBC), bamboo (BBC), and rice husk (RHBC)—and their application in wall components (as blocks and as boards). A cradle-to-grave, carbon-focused Life Cycle Assessment (LCA) was used to compare these bio-concretes to conventional masonry and industrialized light-framing solutions. Each bio-concrete family incorporated biomass volumetric fractions of 40%, 45%, and 50%, using a ternary cementitious matrix of cement, rice husk ash, and fly ash (0.45:0.25:0.30). Sensitivity analyses examined the impacts of transport distances and the parameters affecting biogenic carbon storage, such as carbon retention periods in the built environment. The carbon footprint results demonstrated a significantly low or negative balance of emissions: WBC ranged from −109 to 31 kgCO₂-eq./m³, BBC from −113 to 28 kgCO₂-eq./m³, and RHBC from 57 to 165 kgCO₂-eq./m³. The findings emphasized the importance of ensuring bio-concrete durability to maximize biogenic carbon storage and highlighted the environmental advantages of bio-concrete wall systems compared to conventional solutions. For instance, BBC boards replacing fiber cement boards in light-framing systems achieved a 62 kgCO₂-eq./m² reduction, primarily due to the production (A1–A3) and replacement (B4) stages. This research outlines the emission profiles of innovative materials with the potential to mitigate global warming through circular construction, offering a sustainable portfolio for designers, builders, and AECO professionals seeking non-conventional solutions aligned with circular economy principles. Full article

Wood is the most commonly used material for framing single-family houses in the USA, yet alternative materials like Insulated Concrete Forms (ICFs) offer potential advantages in energy efficiency and thermal performance. This study evaluates ICFs as a viable alternative by analyzing the energy performance and indoor temperature stability of five single-family houses in Oklahoma, USA, monitored over 12 months. The sample included a total of five single-family houses: two wood-framed houses with blown fiberglass insulation, one wood-framed house with spray foam insulation in the attic, and two houses with ICF exterior walls. Results demonstrated that ICF houses consumed up to 41% less electricity and at least 5% less natural gas compared to wood-framed houses, with improved indoor temperature stability. Occupants also saved approximately USD 270 annually on energy costs, highlighting the advantage of ICF’s efficiency. This study provides empirical evidence of the benefits of ICF construction, which previously relied heavily on simulations or anecdotal claims. However, findings are limited by the specific geographic focus of the study. Future research should expand on these findings by incorporating a wider range of climates and housing designs to better understand the broader applicability of an ICF as an alternative to conventional wood-framed construction. Full article

In response to concerns over resource shortages and environmental impacts, biobased materials are increasing in popularity. This includes an interest in replacing traditional vapour control systems, including polyethene (PE) membranes. However, the susceptibility of these materials to moisture-related degradation poses challenges. This study examines the water vapour diffusion resistance of the vapour retarder and the wind shield as key properties. Examining wood frame walls designed with low water vapour diffusion resistance wind shields, this study analyses the necessary properties of the vapour retarder as a function of the properties of the wind shield. We evaluated exterior wood frame walls that were thermally insulated with materials including mineral wool and biobased options such as flax, grass, wood fibre, straw, and cellulose. Using WUFI Pro software, we determined the relations between properties necessary to prevent mould growth. Hygrothermal simulations determined the necessary properties of the vapour retarder as a function of the properties of the wind shield. Analyses were carried out in temperate cold climates. Wind shield diffusion tightnesses ranging from 0.01 to 1 (m²·s·GPa)/kg were evaluated. Assessments were performed for walls with a U-value of 0.15 and 0.10 W/(m²·K). The indoor humidity classes 1 to 3, as defined in EN ISO 13788, were used for the simulations. The results indicate that the necessary properties of the vapour retarder depend on the properties of the wind shield, as well as the insulation material, the indoor humidity, and the U-value. As the wind shield diffusion tightness decreases, the necessary vapour retarder diffusion tightness also decreases, eventually reaching a fixed value determined by the insulation material, the indoor humidity, and the U-value. Full article

In a Brazilian subtropical climate, Wood Frame construction, valued for sustainability and thermal inertia, is being tested for compatibility with Phase Change Materials (PCMs) to improve thermal performance. This study addresses the lack of research on these technologies in Brazil and evaluates the thermal performance of a single-story Wood Frame housing envelope with and without PCM in Curitiba-PR, located in southern Brazil with Cfb climate classification. Dynamic energy simulation followed ASHRAE Standard 55-2017 criteria for occupant thermal comfort. The results indicated that integrating PCM with thermal insulation (EPS) significantly improved thermal performance, reducing the daily indoor temperature range by up to 6.4 °C and increasing comfortable hours by 20%. However, Wood Frame construction without either BioPCM or EPS proved inadequate in achieving the minimum level of thermal performance required by Brazilian standards. This underscores the importance of evaluating potential users’ thermal comfort conditions alongside the building’s overall thermal performance. It also emphasizes the need to carefully consider the level of thermal insulation in conjunction with PCM for effective design decisions. Thus, this study promotes the integration of PCM and thermal insulation to enhance thermal comfort and sustainability in Wood Frame constructions in the subtropical climate of Brazil. 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