Search Results (58)

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 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 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

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 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

This paper presents a mathematical model for predicting vibrations in lightweight, timber-based floor/ceiling structures, enhanced to account for irregularities in joist shape and stiffness, as well as floor stiffness. Building on a prior model that assumed precise geometry and homogeneous material properties, the study now incorporates real timber measurements via the power spectral density of irregularities to incorporate their impact on the system’s vibrational response, including mid-frequency vibrations. Existing results underscore the critical role of component connections in shaping vibration behavior, while the present paper gives new principles for building a model to assess how uncertainties in these connections or material properties affect the overall structural response. This new model maintains the property of efficient computation so that irregularities in the components may be included in the design stage to improve the mid-frequency performance of lightweight, timber-framed structures. Full article

Mangroves are essential for the well-being of the inhabitants of coastal areas, who have extensive knowledge about the use and exploitation of this resource. However, this knowledge is decreasing, which could trigger negative repercussions for this ecosystem. Ethnobiological investigations make it possible to gather information on the use, management, and exploitation of this resource. Hence, this paper presents a study that is framed around the coastal area of the state of Tabasco, in southeast México, and consists of 74 semi-structured interviews that were carried out, while the local relevance of each mangrove species was evaluated using ethnobiological indices. Three species of mangrove were identified, Avicennia germinans, Laguncularia racemosa, and Rhizophora mangle, and the latter species had the highest Use-Value (UV) Index value of 6.08. A total of 27 forms of forestry use were found, 11 for non-timber use and 16 for timber use. Firewood stood out as the main use with 12.6%, while the use of needles to make cloth and crafts represented the lowest percentage with 0.3%. The uses given by the coastal population to the mangroves and their respective species were influenced by immediate needs and specific characteristics of each species. To ensure the sustainability of mangroves, it is essential to design environmental strategies that integrate local ethnobiological knowledge and promote the active participation of direct users of this ecosystem. These strategies should be incorporated into public conservation policies, recognizing the cultural and economic value that mangroves hold for local communities. By implementing these actions, the relationship between communities and their environment will be strengthened, laying the groundwork for further exploration of coastal ethnobiology. Full article

Increased timber construction is putting pressure on Ireland’s limited structural-grade timber stock, while recovered timber is currently downcycled or incinerated. Design for Adaptability, disassembly and reuse (DfADR) has emerged as a response to this wasteful linear process, which can increase the life span of structures, the ease of disassembly during and after use, and improve the quality of recovered material. However, while many DfADR strategies have been identified, uptake in architectural practice is lacking. Impediments to DfADR were identified through an analysis of an existing timber-framed structure and a modified design developed based on the ISO 20887:2020 principles to illustrate practical solutions. In tandem, a decision tool was developed that organised the plethora of identified strategies by the ISO principles and the work stages used by designers to facilitate integration into practice. Modest reconfigurations of the space and roof structure increased adaptability, access to services for replacement and repair, and expansion potential to increase service life, while rationalized timber sizes improved reuse potential. Using wood nails in stud and joist framing, with screws replacing nails elsewhere, and omitting adhesives from the floor panels increased the ease of disassembly. These relatively minor changes resulted in nearly 3 times the amount of solid timber with a high reuse potential (≥2348 mm) recovered over the original design, highlighting the impact DfADR can have on the recoverability and reusability of timber. Full article

High-rise timber structures signify a rising trend, thanks to their significant environmental and economic advantages that occur over their complete lifespan. Enhancing spatial effectiveness in these structures is a critical design consideration for project feasibility. Currently, there has been no comprehensive study on the space efficiency of such towers. This article analyzed 79 cases all over the world to deepen the knowledge of design features shaping spatial efficiency. The critical findings are as follows: (1) the most common architectural preferences include residential function, a centrally located service core, and prismatic arrangements; (2) the preferred structural material is composite, while a shear walled frame system is the favored structural system; (3) the average spatial efficiency and percentage of core area to GFA were recorded at 84% and 10%, ranging from the lowest values of 70% and 4% to the highest values of 95% and 21%, respectively; and (4) no significant differences were detected in the effect of core design approaches on spatial effectiveness if appropriately planned, with similar inferences drawn concerning form and the structural material used. This article will assist in developing design directions for different interested parties, including architectural designers taking part in the advancement of high-rise timber towers. Full article

Timber-framed masonry structures are widely used around the world, and their seismic performance is generally poor. Most of them have not been seismically strengthened. In areas with high seismic fortification intensity, there are great potential safety hazards. And it is urgent to carry out effective seismic reinforcement. However, due to the complicated construction process of the existing reinforcement technology, the poor durability of the reinforcement materials, and the significant disturbance to the life of the original residents, an efficient single-story timber-framed masonry structure reinforcement technology suitable for comprehensive promotion and application has not been explored. In this paper, a fiber-reinforced cement mortar (FRCM) material was proposed. A 1/2 scale model of a single-story timber-framed masonry structure was taken as the research object. The method of strengthening a single-story timber-framed masonry structure with FRCM layer was adopted. And the shaking table test of the model before and after reinforcement was carried out in turn. The dynamic characteristics, failure modes, acceleration response and displacement response of the FRCM layer-strengthened structure were analyzed through comparisons of the two cases. The experimental results showed that the FRCM layer significantly improved the seismic performance of the seismic-damaged single-story timber-framed masonry structures. The X- and Y-direction natural frequencies of the model structure were increased by 31.30% and 30.22%, respectively, after the structure was strengthened with FRCM. During a rare eight-degree earthquake, the inter-story displacement angles in the X- and Y-direction of the unreinforced model reached 1/98 and 1/577, respectively, and the structure was destroyed, while the inter-story displacement angle of the FRCM-reinforced model was only 1/2 of that the unreinforced model. During a rare nine-degree earthquake, the X-direction inter-story displacement angle of the model strengthened with FRCM reached 1/78 and the Y-direction inter-story displacement angle reached 1/178. At this time, the reinforced model structure was destroyed, but there was no collapse of the structural components, which met the seismic design objectives of “operational under the design minor seismic intensity, repairable damage under the design seismic precautionary intensity, and collapse prevention under the design rare seismic intensity”, which proved that the FRCM layer was an effective and feasible way to strengthen the existing single-story wood-masonry rural building. Full article

It is in the preliminary design phase of a project that the designer makes decisions concerning the global geometry of the structure. When working with space frames, the choice of the frame topology is key for the structural behavior. It is difficult to find manuals that provide guidance on which of the most common topologies is the right one for the project, let alone in wood construction. In response to this shortcoming, the use of parametric software is proposed (Grasshopper build1.0.0007 and Karamba 3D 2.2.0.16-220828). The aim is to create a dynamic catalog that responds instantaneously to changes in the parameters to provide information on structural behavior, pre-dimensioning and metrics. With the display of all this information, the architect will have enough technical argumentation to choose or reject options. The proposal is developed through a case study: the early design and analysis stages of flat double-layer timber spatial frames as for rectangular medium-span roofs. Full article

High-rise office structures constructed using timber material (with a minimum of eight stories) signify a burgeoning and favorable sector, mainly owing to their ability to offer substantial environmental and economic advantages across their lifespan. However, it is crucial to recognize that the current corpus of scholarly literature lacks a thorough investigation into vital aspects concerning the architectural and structural planning of these sustainable structures. In an effort to fill this gap and augment the understanding of advancing international tendencies, this paper delved into data originating from 27 high-rise offices on a worldwide scale. The primary findings were: (i) Central core arrangements were the most popular, accounting for 67%, followed by peripheral types at 22%. (ii) Prismatic designs were the most frequently used at 85%, with free forms making up 11%. (iii) Material combinations involving timber and concrete were widely prevalent, making up 70% of composite constructions, which were 74% of the sample group, with pure timber constructions at 26%. (iv) Structural systems predominantly utilized shear walled frame systems, comprising 85% of the total. This article serves as a valuable resource for architectural designers, offering guidance on planning and executing future sustainable developments in the domain of high-rise timber office. Full article

To reduce the negative impact on the environment, architects, designers, and construction companies need to find and apply eco-friendly and sustainable building solutions. Due to its renewable nature and numerous advantages, timber has become an attractive substitute for steel and concrete in both residential and non-residential construction projects. However, timber application in the construction of grocery stores is a relatively new concept. The purpose of this research is to propose three alternative timber-based structural systems for a grocery store in Lithuania and to select the most efficient option based on multi-criteria decision-making methods. Three alternative glued laminated timber (glulam) structural systems—the glulam column and truss system, the glulam three-hinge frame system, and the glulam column and double-tapered beam system—were designed. The systems were evaluated against ten criteria, reflecting structural properties, cost efficiency, assembling complexity, and aesthetics. Multiple-criteria assessments by the COmplex PRoportional ASsessment (COPRAS) method and simple additive weighting (SAW) method revealed that the best-performing alternative is the glulam column and double-tapered beam system due to the lower cost of load-bearing structures, the smaller quantity of required steel details and fittings, and the highest maximum utility ratio according to serviceability limit states compared to other alternatives. Full article

The main purpose of this study is to quantify and compare the embodied carbon (EC) from the materials used or designed to build the Adohi Hall, a residence building located on the University of Arkansas campus in Fayetteville, AR. It has been constructed as a mass timber structure. It is compared to the same building design with a steel frame for this study. Based on the defined goal and scope of the project, all materials used in the building structure are compared for their global warming potential (GWP) impact by applying a life cycle assessment (LCA) using a cradle-to-construction site system boundary. This comparative building LCA comprises the product stage (including raw material extraction, processing, transporting, and manufacturing) plus transportation to the construction site (nodule A1–A4, according to standard EN 15804 definitions). In this study, GWP is primarily assessed with the exclusion of other environmental factors. Tally^®, as one of the most popular LCA tools for buildings, is used in this comparative LCA analysis. In this study, the substitution of mass timber for a steel structure with a corrugated steel deck and concrete topping offers a promising opportunity to understand the GWP impact of each structure. Mass timber structures exhibit superior environmental attributes considering the carbon dioxide equivalent (CO₂ eq). Emissions per square meter of gross floor area for mass timber stand at 198 kg, in stark contrast to the 243 kg CO₂ eq recorded for steel structures. This means the mass timber building achieved a 19% reduction in carbon emissions compared to the functional equivalent steel structure within the building modules A1 to A4 studied. When considering carbon storage, about 2757 tonnes of CO₂ eq are stored in the mass timber building, presenting further benefits of carbon emission delays for the life span of the structure. The substitution benefit from this construction case was studied through the displacement factor (DF) quantification following the standard process. A 0.28 DF was obtained when using mass timber over steel in the structure. This study provides insights into making more environmentally efficient decisions in buildings and helps in the move forward to reduce greenhouse gas (GHG) emissions and address GWP mitigation. Full article

Modular timber construction embodies a pioneering and eco-friendly methodology within the building sector. With the notable progress made in manufacturing technologies and the advent of engineered wood products, timber has evolved into a promising substitute for conventional materials such as concrete, masonry, and steel. Beyond its structural attributes, timber brings environmental advantages, including its inherent capacity for carbon sequestration and a reduced carbon footprint compared to conventional materials. Timber’s lightweight nature, coupled with its versatility and efficiency in factory-based production, accelerates modular construction processes, providing a sustainable solution to the growing demands of the building industry. This work thoroughly explores contemporary modular construction using wood as the primary material. The investigation spans various aspects, from the fundamentals of modularity and the classification of modular timber solutions to considerations of layout design, structural systems, and stability at both the building and module levels. Moreover, inter-module joining techniques, MEP (mechanical, electrical, and plumbing) integration, and designs for disassembly are scrutinized. The investigation led to the conclusion that timber modular construction, drawing inspiration from the steel modular concept, consistently utilizes a structural approach based on linear members (timber frame, post-and-beam, etc.), incorporating stability configurations and diverse joint techniques. Despite the emphasis on modularization and prefabrication for adaptability, a significant portion of solutions still concentrate on the on-site linear assembly process of those linear members. Regarding modularity trends, the initial prevalence of 2D and 3D systems has given way to a recent surge in the utilization of post-and-beam structures, congruent with the ascending verticality of buildings. In contrast to avant-garde and bold trends, timber structures typically manifest as rectilinear, symmetric plans, characterized by regular and repetitive extrusions, demonstrating a proclivity for centrally located cores. This work aims to offer valuable insights into the current utilization of modular timber construction while identifying pivotal gaps for exploration. The delineation of these unexplored areas seeks to enable the advancement of modular timber projects and systems, fully leveraging the benefits provided by prefabrication and modularity. Full article