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Abstract
Wood is the most widely used building material in the United States because of its efficiency, durable, and usefulness. One of the greatest attributes of wood is that it is a renewable resource, it has low carbon impact and low embodied energy. The amount of energy needed for producing wood products is much less than comparable products made from other materials. Carbon in wood remains stored until the wood deteriorates or is burned. Architects, product designers, material specifiers, and homeowners are increasingly asking for certified building products that are from sustainable resources. More than 50 different forest certification systems in the world represent nearly 700 million acres of forestland and 15,000 companies involved in producing certified products. In terms of forest acreage under certification, Forest Stewardship Council (FSC) and Sustainable Forestry Initiative (SFI) dominate in the United States.
... Timber can be considered a carbon negative material, at least in the short-term as noted in Table 1. Wood removes carbon from the atmosphere through photosynthesis (Falk 2010): ...
... Because wood requires low energy during processing and more than 60% of this energy comes from biofuel, a carbon-neutral energy source, the embodied energy in timber is much lower than other construction materials (Falk 2010). Half of the energy required to produce lumber goes into drying the wood in a kiln. ...
... However, EW products, such as oriented strand board and composite lumber, use wood chips manufactured from smaller trees from shorter rotation harvests. These trees sequester more CO 2 than those in longer-rotation forests (Falk 2010). This balances some of the additional embodied energy required to process EW products. ...
The main objective of infrastructure design codes is to protect the public’s welfare, health, and safety, none of which appear directly related to the current sustainability movement that has focused on protecting the natural environment, conserving resources, and minimizing the toxicity of construction materials and processes. Some United States jurisdictions have adopted language related to sustainability based on the United States Green Building Council to curtail adverse effects of global climate change, minimize environmental impact of new construction of built assets (i.e., buildings and infrastructure), and in some cases, improve air quality in the community. The focus of this paper is to compare the embodied energy and carbon footprint of various construction materials: concrete, steel, timber, masonry, and fiber reinforced composites. To properly compare these materials from a sustainability standpoint, we propose an index that characterizes material ecological properties by dividing strength and stiffness by embodied energy. The index is similar to the structural specific properties index used to characterize the mechanical properties of materials (i.e., strength and stiffness divided by density). Using this ecological index, concrete and steel appear to be the most sustainable materials. As a result of their higher strength and stiffness, concrete and steel require less embodied energy to satisfy specific structural demands. Keywords: embodied energy, carbon footprint, LEED, specific embodied energy
... To align with the objectives outlined in the Paris Agreement aimed at limiting global warming to below 2 • C by 2100, the construction industry must transition to carbon-neutral or carbon-negative practices by 2030 [2,3]. Timber exhibits a low net carbon emission (NCE), expressed in kilograms of carbon per ton (kg C/t), approximately one-fifth that of glass and one-nineth that of concrete [4]. The drive to minimize the environmental footprint of the construction sector has reignited interest in timber-based architecture. ...
... Timber construction offers inherent energy efficiency, sustainability, and reduced greenhouse gas emissions, and supports sustainable forestry practices. Moreover, timber serves as a means of carbon sequestration, with wood products containing approximately 2.5 billion tons of carbon [4]. However, timber architecture presents notable challenges, particularly regarding fire safety. ...
Traditional wood protection methods involving fire retardants and preservative paints have limitations, requiring periodic renewal during a building’s lifecycle and generating hazardous waste post-use. This study aims to achieve a multifaceted solution, simultaneously enhancing wood’s resistance to fire, fungi, and insects using natural and/or recycled mineral waste components containing lime that react with pozzolanic additives. Additionally, organic humates provide protection against pests (fungi and insects). Following the crystallization processes within the wood’s structure, it exhibits increased resistance to fire, as demonstrated by tests involving seven species. The study also describes wood tolerance tests against termites (Reticulitermes flavipes) that yielded promising results, indicating that the treated wood is an unsuitable habitat for these pests. An additional advantage for the timber industry is that the crystallized composite filling the wood’s pores minimizes wood stitching and reduces internal stresses during the drying process. This property enhances the utility of timber in frame structures and carpentry joints, which are less susceptible to moisture-induced movements. The timber impregnated by our method can also be repurposed or disposed of as non-hazardous waste. This research thus offers an eco-friendly and effective approach to wood protection.
... In addition to be the most extensively used building material in the US, it has properties that make it applicable to a variety of purposes. From slightly treated logs at a site for constructing homes to high process designed wood composite created in a huge manufacturing facility, wood products are effective, long-lasting, and useful (Falk, 2009;Wieruszewski and Mazela, 2017). ...
... Another major area of focus is selecting construction materials that have favorable environmental attributes. Wood has low embodied energy compared to other building materials (e.g., steel, concrete, aluminum, and plastics) which is defined by the amount of energy needed to harvest, manufacture, and transport materials as well as its final end use (Falk, 2009;Maier, 2021;Udele et al., 2021). Wood, therefore, as a renewable material, is highly sought after for use in construction and building industries. ...
Softwood is more in demand than hardwood because it is used primarily in the US's largest wood-consuming industry, construction, resulting in increased importation of softwood annually to meet this demand. Hardwood, used for non-structural purposes like furniture and interior designs, is more abundant in US forests. However, some hardwood species are underutilized and undervalued. Cross-laminated timber (CLT) has increased the demand for softwood. A study evaluated the mechanical and physical properties of three underutilized hardwood species (321 yellow poplar, 393 sweetgum, and 262 red oak specimens) for CLT industrial mat manufacturing. The results showed that red oak had a higher density than southern yellow pine, and all species had an average modulus of elasticity greater than the CLT lumber requirement. The study confirmed the viability of these underutilized hardwoods for CLT fabrication, suggesting they could be a suitable substitute for softwood in CLT manufacturing.
... These efforts help reduce harvest pressures on the natural forests, providing better opportunities for their sustainable management [42]. Shorter rotation harvests can sequester total carbon than more extended rotation harvests [43]. To achieve sustainability, timber building materials must be produced from certified wood sourced from replanted/sustainably managed forests [37,39]. ...
... To achieve sustainability, timber building materials must be produced from certified wood sourced from replanted/sustainably managed forests [37,39]. The forest resource is renewable, and with proper management (sustainable forest management), a flow of wood products can be maintained forever [8,37,43]. ...
... Incorporating wood-based products, biomass-derived products, and other sustainable materials in the design of EVs and EVCS is relatively novel. Wood is a natural, renewable, and sustainable material (Falk 2009;Jiang et al. 2018;Think Wood 2022;Woodard and Milner 2016). It is abundant, biodegradable, lightweight, and durable, making wood suitable for a wide range of applications (Falk 2009;Jiang et al. 2018). ...
... Wood is a natural, renewable, and sustainable material (Falk 2009;Jiang et al. 2018;Think Wood 2022;Woodard and Milner 2016). It is abundant, biodegradable, lightweight, and durable, making wood suitable for a wide range of applications (Falk 2009;Jiang et al. 2018). Wood has been used in the construction of homes and other low-rise structures for a significant period of human history; however, wood is perceived as an inferior material to concrete and steel for high-rise structures. ...
Electrifying passenger transportation has been a topic of interest for several decades as a method of reducing carbon emissions and promoting a more sustainable society. Globally, nations are implementing policies and regulations, promoting and setting goals for carbon neutrality, lowering carbon emissions, and doing away with combustion vehicles. The electric vehicle (EV) industry has seen significant growth over the past few decades due to increased environmental awareness, political influences, and economic benefits. Even so, before they can become a reliable mode of transportation, significant changes need to be implemented to improve the EV ecosystem. Previous literature has explored issues such as lack of charging infrastructure, charging times, and range anxiety that hinder the mass adoption of EVs. However, to our knowledge, there is no literature that discusses the interdependencies of the EV ecosystem holistically and how many of the aforementioned elements interact. Additionally, there is little discussion on sustainable materials which could be instrumental to EV ecosystem development. This paper attempts to discuss many ecosystem components, present trends, difficulties, and possible frameworks for sustainable advancement. Through this research, we found that the EV ecosystem development will be a collective effort and will rely on the collaboration of multiple actors.
Graphical abstract
... Traditional building materials, including steel, concrete, and aluminium are high energy content materials which consumes high energy during their recycling phase [8], whereas, bio-based materials such as; wood and bamboo are considered as renewable and sustainable material for construction having many positive characteristics, including low embodied energy (i.e. amount of energy required to harvest, mine, manufacture and transport), low carbon impact, and a good service life [10][11][12][13][14][15]. With proper management and harvesting practices, the flow of wood and bamboo-based products can be sustained forever [10,16] that can help to fulfill the criteria of green buildings [11][12][13]. ...
... amount of energy required to harvest, mine, manufacture and transport), low carbon impact, and a good service life [10][11][12][13][14][15]. With proper management and harvesting practices, the flow of wood and bamboo-based products can be sustained forever [10,16] that can help to fulfill the criteria of green buildings [11][12][13]. ...
Laminated bamboo and bamboo scrimber are value-added engineered forms of bamboo produced in standard shape and size, with better physical and mechanical characteristics that make them highly attractive for structural applications. Other than engineered bamboo, bamboo as a reinforcement can be used to replace steel bars in concrete structures. The present study summarizes the progress in research work carried out for establishing bamboo as a sustainable construction material covering the different aspects, namely, the processing of bamboo, physical and mechanical properties, and fire performance of bamboo-based structural elements. The chemical and thermal treatment of bamboo, along with the optimization of various processing parameters, significantly influence the physical and mechanical behaviour of engineered bamboo elements. Bamboo scrimber is having better mechanical properties as compared with laminated bamboo elements. Bamboo undergoes a pyrolysis process above 150 • C and losses mass and strength at elevated temperatures. The charring rate for bamboo scrimber is lower than the laminated bamboo, and the use of fire-retardant coating materials is highly significant in controlling the heat release rate and suppressing the release of toxic gases. Bamboo reinforcement of around 4% is an optimum value to control the cracking and enhance the strength and toughness of the concrete matrix. The use of water replant coatings, and mechanical anchorage are recommended to enhance the bond strength of bamboo reinforcement and cement matrix. Bamboo-reinforced concrete (BRC) elements coated with the fire-protective compound can withstand higher temperatures (500 • C or more) without concrete spalling. BRC panels are highly suitable for constructing lightweight and cost-efficient walling systems. This review work illustrates the potential of engineered bamboo and BRC elements to meet the growing demand for low-cost housing.
... The long-term preservation of this material is an important issue in the field of cultural heritage (CH) where it has long been used as a building material and for handcrafted wooden objects. In recent years it has also been enlightened in modern building construction as a strong, lightweight, and sustainable material that can lead the decarbonisation of built environments [2][3][4][5][6][7]. Despite those attractive properties, due to its nature and chemical components, wood is most sensitive to biological degradation and environmental climate-induced decay, which might affect the wood's physical and mechanical properties. ...
... ε ms . In the field of cultural heritage, an adjustment could be made to Equation (5). The thermal strain ( . ...
In the world of cultural heritage, a wide range of artefacts and buildings are made of wood and, therefore, are subjected to moisture-induced stress and strain cycles, owing to environmental fluctuations. Simultaneous action of moisture and mechanical loads lead to a mechanosorptive effect on wood. Therefore, an increase in time-dependent creep, due to mechanical loads, is observed. The assessment of these complex phenomena entails the use of advance and interdisciplinary approaches. Consequently, this article reviews experimental and mathematical methods to study these degradation mechanisms in wooden artefacts and timber elements in heritage buildings. The paper presents the results of a six-step descriptive literature review, providing an overall picture of the ongoing research. Experimental techniques need to be improved so that they are in line with the conservation principles. The combination of experiments and simulations is a reliable predictive approach for better assessing the potential risk damages due to temperature, humidity cycles, and mechanical loads in complex structures. Thus, advanced numerical simulations and mathematical modelling include climate data and experimental measurements. This work also provides an overview of research performed on different categories of cultural heritage characterised by multi-layer structures. The mechanical response to wood–moisture relation is affected by the level of complexity of these structures. Finally, the use of realistic models is limited by knowledge about the material properties and the behaviour of complex structures over time. In addition, research gaps, limitations, and possible future research directions are also provided. This review may represent a starting point for future research on the thermo-hygro-mechanical behaviour of wood heritage.
... The industry also is considered one of low environmental impact because wood is a renewable resource (USDA Extension Foundation 2022). Wood is a versatile raw material and naturally possesses the ability to sequester carbon, which is chemically stored in the wood (Falk 2009, Falk et al. 2013. The carbon usually stays in the wood up until the natural end of its life cycle. ...
... Recovering and repurposing lumber from waste streams gives wood a ''second life'' and decreases the amount of landfill waste. Most wood from demolition processes is sent to landfills where the wood either deteriorates or is burned, emitting greenhouse gases into the atmosphere (Falk andMcKeever 2012, Hossain andPoon 2018). Thus, wood reuse promotes the continuation of carbon storage, which helps to reduce the carbon footprint. ...
Wood has thousands of uses and the industry plays an important role in the US economy. There are many sectors within the industry such as the lumber, engineered wood products, pulp and paper products, and reclaimed lumber sectors. However, most consumers are unaware of the importance and the diversity of the industry. Reclaimed lumber is one particular sector that can have a great economic and environmental impact among communities. In 2021, an online survey was conducted to assess consumer knowledge of the reclaimed lumber sector and perceptions and attitudes toward the sector and reclaimed lumber products. Of the 1,516 respondents, 59 percent indicated being somewhat knowledgeable of the wood products industry but only 44 percent felt they were knowledgeable of reclaimed lumber. Caucasian and male respondents were more likely to indicate they were knowledgeable. Although respondents had somewhat negative responses toward the environmentally friendliness of the industry, their responses toward the environmental and economic benefits of reclaimed lumber products were positive. The information obtained from this study will be beneficial to companies that are interested in creating strategies to market new or innovative products to reach new or existing customers.
... Kokmateriāla kombinācija ar betonu, kas ir stingāks materiāls ar lielu spiedes stiprību, ievērojami palielina nestspēju, konstrukcijas kopējo stingumu un izturību pret apkārtējas vides iedarbību, līdz ar to arī konstrukcijas kalpošanas laiku [6,7]. Turklāt kokbetons, salīdzinot ar betonu, veido ilgtspējīgākas būvkonstrukcijas, jo izmanto atjaunojamus dabas resursus, ir saistīts ar zemākām oglekļa emisijām un tā ražošanai ir nepieciešams neliels enerģijas daudzums [8,9]. Koksne kā konstruktīvais materiāls apvieno lielu lieces stiprību ar mazu svaru, kas rada būtisku priekšrocību, salīdzinot ar citiem konstruktīvajiem materiāliem. ...
... The combination of timber with concrete, a stiffer material with high compressive strength, significantly increases the load-bearing capacity, the overall stiffness of the structure and resistance to the effects of the surrounding environment, thus also the service life of the structure [5], [6]. In addition, compared to concrete, timber-concrete composite provides more sustainable building structures that use renewable natural resources, it is associated with lower carbon emissions and requires a small amount of energy for its production [8], [9]. Timber as a construction material combines high bending strength with low weight, which is a significant advantage compared to other construction materials. ...
Within the framework of the Thesis, a sustainable solution of timber-concrete composite structure has been developed with an innovative method of producing a rigid connection, which ensures the most effective synergy of materials. The performance of the full composite action has been investigated by numerical experiments as well as laboratory bending and shear tests. A methodology and software based on it have been developed for the determination of rational cross-section parameters and materials of timber-concrete composite slabs with full composite action. The possibilities of effective use of operational modal analysis and ultrasonic testing for construction quality control have been tested and determined.
... TCC can o er numerous advantages. Timber, in terms of production, requires small amounts of nonrenewable energy, different steel, and concrete, as it is a natural, sustainable material [8,9]. Furthermore, timber is a carbon store that can decrease the environmental impact of construction through its carbon sequestration mechanism, which is the process of restoration or removal of CO 2 from the atmosphere using a physical or biological process [10,11]. ...
... After the wood fibers cracked, the load was increased manually until the lag screw would yield ( Figure 6). Once the lag screw yielded and had a noticed bent, the load was increased until the specimen (6) and (8)) 7.0 18.6 (equation (14)) 17.8 (equation (8)) 19.8 (equations (6) and (9)) 8. 9 13.7 (equation (14)) 17.8 (equation (8)) 15.4 (equations (6) and (9)) Advances in Civil Engineering could not resist any further loads. In most of these trials, the lag screw almost behaved in elastic deformation, but it did not return to its original position (zero deflection), which means that with lag screws, the elastic limit cannot take place within this type of connection, as proved by Newlin and Martin Gahagan in 1938 too [40]. ...
Push-out-shear tests were used in this study to analyze lag screw connections in timber-concrete composite (TCC) slabs based on the embedment depth. The goal of this research is to look into the relationship between shear capacity and embedment depth in TCC, as well as to investigate the embedment strength of the wood. Experiments were carried out at different embedment depths (5.08 cm, 7.0 cm, and 8.9 cm). The prepared samples were examined in order to determine the failure modes and provide an accurate assessment of the influence of embedment depth on TCC slabs. The investigation on the embedment strength of the wood was performed then for the analysis of the crushing of wood fibers, lag screw yielding strength, and maximum load applied at embedment depths of 6.6 cm and 7.0 cm. The results indicate that between 5.08 cm and 7.0 cm, there was an apparent improvement in the relationship between embedment depth (ED) and shear capacity of TCC slabs in terms of the shear strength, while a significant difference was observed between 7.0 cm and 8.9 cm. The study suggests that the ED of the TCC slab should be maintained at around 7.33 times the diameter of the lag screw.
... The production and processing of wood-based building products requires less nonrenewable energy consumption than many other materials used in construction (e.g., concrete, steel, aluminum, or plastic) (Werner and Richter 2007). In addition, wood products can store the carbon, avoiding carbon dioxide emissions into the atmosphere during the lifetime of the building (Frühwald 2007;Falk 2009;Köhl and Frühwald 2009). Unlike the other materials mentioned, wood products come from a sustainable source, and decision-makers are increasingly asking for certified building products (Falk 2009). ...
... In addition, wood products can store the carbon, avoiding carbon dioxide emissions into the atmosphere during the lifetime of the building (Frühwald 2007;Falk 2009;Köhl and Frühwald 2009). Unlike the other materials mentioned, wood products come from a sustainable source, and decision-makers are increasingly asking for certified building products (Falk 2009). ...
Recent studies have shown the advantage of wood impregnation on increasing the dowel-bearing strength of black spruce wood by almost 50%. The aim of the present study was to improve the mechanical performance of a dowel-type connection through an impregnation method for black spruce wood. The results showed that wood treatments improved the mechanical performance of dowel-type connections. The dowel-bearing strength increased up to 25%, while the stiffness increased up to 52%. The increase obtained was lower in comparison with the previous studies, however. A lower polymer quantity, resulted in a shorter vacuum time, and a lower temperature polymerization used in wood treatment brought the process closer to an industrial application.
... In the intricate fabric of Earth's ecological system, they are indispensable entities, ensuring the vitality and equilibrium of our planet's ecological balance. When a tree is harvested, the wood can be used in every stage of human society, such as papermaking, construction, and furniture manufacturing (Falk, 2009;Latib et al., 2020). Approximately 73,000 tree species exist worldwide, but excessive logging and timber over-exploitation have resulted in up to 30% of the world's tree species being at risk of extinction, along with biodiversity destruction, soil erosion, and other ecological problems (Brancalion et al., 2018;Cazzolla et al., 2022;IUCN, 2022). ...
Introduction
Global illegal trade in timbers is a major cause of the loss of tree species diversity. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) has been developed to combat the illegal international timber trade. Its implementation relies on accurate wood identification techniques for field screening. However, meeting the demand for timber field screening at the species level using the traditional wood identification method depending on wood anatomy is complicated, time-consuming, and challenging for enforcement officials who did not major in wood science.
Methods
This study constructed a CITES-28 macroscopic image dataset, including 9,437 original images of 279 xylarium wood specimens from 14 CITES-listed commonly traded tree species and 14 look-alike species. We evaluated a suitable wood image preprocessing method and developed a highly effective computer vision classification model, SE-ResNet, on the enhanced image dataset. The model incorporated attention mechanism modules [squeeze-and-excitation networks (SENet)] into a convolutional neural network (ResNet) to identify 28 wood species.
Results
The results showed that the SE-ResNet model achieved a remarkable 99.65% accuracy. Additionally, image cropping and rotation were proven effective image preprocessing methods for data enhancement. This study also conducted real-world identification using images of new specimens from the timber market to test the model and achieved 82.3% accuracy.
Conclusion
This study presents a convolutional neural network model coupled with the SENet module to discriminate CITES-listed species with their look-alikes and investigates a standard guideline for enhancing wood transverse image data, providing a practical computer vision method tool to protect endangered tree species and highlighting its substantial potential for CITES implementation.
... Managing the trade-offs between carbon sequestration, wood production, and water security will require an understanding of the regional relationship between forests, productivity, and water use. In terms of water footprint and carbon sequestration capability, wood stands over other structural materials (see Falk (2009) ...
This paper reviews the current knowledge of hydrological processes in Chilean temperate forests which extend along western South America from latitude 29° S to 56° S. This geographic region includes a diverse range of natural and planted forests and a broad sweep of vegetation, edaphic, topographic, geologic, and climatic settings which create a unique natural laboratory. Many local communities, endangered freshwater ecosystems, and downstream economic activities in Chile rely on water flows from forested catchments. This review aims to (i) provide a comprehensive overview of Chilean forest hydrology, to (ii) review prior research in forest hydrology in Chile, and to (iii) identify knowledge gaps and provide a vision for future research on forest hydrology in Chile. We reviewed the relation between native forests, commercial plantations, and other land uses on water yield and water quality from the plot to the catchment scale. Much of the global understanding of forests and their relationship with the water cycle is in line with the findings of the studies reviewed here. Streamflow from 2 forested catchments increases after timber harvesting, native forests appear to use less water than plantations, and streams draining native forest yield less sediment than streams draining plantations or grassland/shrublands. We identified 20 key knowledge gaps such as forest groundwater systems, soil-plant-atmosphere interactions, native forest hydrology, and the effect of forest management and restoration on hydrology. Also, we found a paucity of research in the northern geographic areas and forest types (35-36° S); most forest hydrology studies in Chile (56%) have been conducted in the southern area (Los Rios Region around 39-40° S). There is limited knowledge of the geology and soils in many forested areas and how surface and groundwater are affected by changes in land cover. There is an opportunity to advance our understanding using process-based investigations linking field studies and modeling. Through the establishment of a forest hydrology science "society" to coordinate efforts, regional and national-scale land use planning might be supported. Our review ends with a vision to advance a cross-scale collaborative effort to use new nationwide catchment-scale networks Long-term Ecosystem Research (LTER) sites, to promote common and complementary techniques in these studies, and to conduct transdisciplinary research to advance sound and integrated planning of forest lands in Chile.
... Bhutan has a great forest cover of 71% [68], and its constitution mandates a minimum coverage of 60% for all times to come. The forest resource is considered renewable, and with proper management (sustainable forest management), a steady supply of wood products can be achieved [56], [69]. Demonstration projects could provide valuable insights into these uncertainties. ...
The construction industry contributes significantly to global energy and CO2 emissions. Besides, the construction model in Thimphu, Bhutan, is expensive. This study appraised the prevalent construction material of a typical multi-storied residential structure from the cost and sustainability perspective. The cost assessment revealed almost 300% cost escalation of sand in Thimphu, followed by common infill wall material of autoclave aerated concrete blocks and red bricks, all impacting the construction costs. Using the process-based method, sustainability assessment estimated production embodied energy and CO2 emissions of 2.5GJ/m 2 and 203KG/m 2 , respectively. This estimate implies the energy and carbon-intensive nature of the urban building stock, a trend likely to be aggravated increasing similar construction activities unless alternatives become available. Our investigation provided scientific evidence of construction issues from specific lenses. Further comprehensive studies are needed to provoke innovative restructuring of conventional inadequacies into a more productive, cost-effective, and sustainable building industry.
... Wood is a recyclable and cost-effective material, which also stands out given the global climate crisis as it helps to reduce the carbon footprint (Falk, 2009;Ross, 2021). With the need to conserve energy resources and avoid the emissions of gases influencing global warming, there is a global demand that calls for materials such as wood with a low carbon footprint (Himes & Busby, 2020). ...
In recent years, wood has gained important significance in construction, with several developments and research conducted. Despite this, some species show scarce dedicated research on the mechanical behavior and data about material parameters is limited. Timber exhibits variable mechanical properties influenced by several factors. Particularly, when subjected to certain stress states, wood tends to display a quasi-brittle behavior, which is noticeable in structural elements like trusses or beams. Identifying fracture strength parameters then becomes crucial for accurately predicting structural behavior. This paper introduces the application of a methodology to characterize fracture strength in Chilean radiata pine by finite element simulations. Utilizing phenomenolog-ical models developed for composite materials and implemented in the commercial finite element software Ansys, a methodology to fit strength parameters based on techniques such as Design of Experiments and Optimization algorithms is applied. Subsequently, and to validate the methodology , numerical predictions are compared with experimental results from tensile, three-point, and four-point bending tests. In the simulations, the finite element is deactivated after reaching the failure criterion, reducing the overall stiffness of the structure. The results, employing the obtained parameters, align closely with experimental findings, demonstrating the adequacy of the proposed framework. This methodology offers a robust approach to accurately determine material parameters, even in scenarios with incomplete or scattered material data, ensuring reliable characterization.
... ** Significant at the 5% level. *** Significant at the 1% level.Buildings 2024,14, 557 ...
The distinct cultural environment of various regions leads to unique consumer preferences for building facades, including the colours and materials that are used for the exteriors of condominium buildings. Understanding these preferences holds significant industry reference value for urban planning authorities and residential development companies. However, the colour and material aesthetic preferences of consumers for building facades have not received much research attention. To fill this gap, this study empirically investigates these preferences within the cultural context of Fuzhou, China. Using house prices as a reference perspective and econometric methods as research tools, this study explores the specific aesthetic preferences of urban consumer groups and compares the preferences of groups with different levels of consumption. The results confirm the existence of specific consumer preferences for building facade colours and materials and a close connection among the variations in these preferences and various combinations of facade colours and materials. Different quantities and types of materials can lead to distinct preferences for the quantities and features of facade colours. Apart from providing precise professional insights for urban planning authorities and residential developers, this study also offers a feasible conceptual reference for future studies to be conducted in other regions.
... These preferences may stem from diverse factors, such as cultural influences that are derived from natural environments, as seen in Finland [8] and New Zealand [9]; economic considerations, as seen in the US [10] and Western Europe [11]; and sustainability demands arising from environmental pressures, as found by Hu et al. [12]. However, this preference scenario is pervasive across the globe, especially in Europe [13], the Americas [14] and Asia [15]. In the context of global urbanisation and construction, preferences for building facade materials become a crucial issue that cannot be overlooked. ...
... These sequester and store atmospheric CO 2 and even after conversion can still have a neutral or even negative carbon footprint. Wood and wood-based products are now widely used in mass timber buildings (Falk, 2009;Salazar and Meil, 2009). However, increasing demand on timber resources requires adopting less-utilized biomass sources for construction. ...
... Wood elements behave elastically, so the ductility and energy dissipation behaviour for timber structures typically depend on the connections. Therefore, a critical step in designing a structural timber system is configuring the connections (Falk 2009). Designing ductile connections to disperse energy has a number of advantages, including the potential to be included in earthquake analysis and improve structural resilience (Ottenhaus et al. 2021). ...
Glued-in rods are efficient and high-capacity connections for achieving high-strength joints in new timber structures and reinforcing existing timber buildings. With the emergence of cross-laminated timber (CLT) and the construction of high-rise buildings, there is a potential for glued-in rods to be adopted in CLT construction. To achieve this goal, the differences between the CLT and the previous engineered wood products and their effect on the strength and the seismic performance of the glued-in rod connections should be investigated. Therefore, this paper investigates the experimental performance of CLT connections with multiple glued-in rods. For this purpose, 42 full-scale tests were conducted, where the specimens were tested under monotonic and cyclic loading by varying embedment lengths of rods and rod to grain angle. The rods were embedded in the parallel to the grain laminations, perpendicular to the grain laminations, and on the boundary of two cross-wised layers. The monotonic tests showed that glued-in rods embedded on the edge of the CLT panel at different angles and locations could provide high-strength connections. Rod to grain angle affected the failure mode and the force vs. displacement curve of the connections. Moreover, the cyclic loadings illustrated that glued-in rod connections keep their elastic properties and initial stiffness until failure. The outcomes of this research demonstrated that glued-in rod connections could offer a reliable and robust connection for CLT construction in seismic active regions.
... Wood can store CO 2 for decades and requires less energy to be manufactured. When wood is compared with other building materials, wood has the lowest impact on the environment (Falk 2009, Sutton 2010). ...
Efficient use of the available wood resources is necessary to sustainably meet the long-term demand for wood products. This paper presents research about the potential of using transverse and longitudinal vibration techniques to evaluate the bending modulus of elasticity MOE (Eb) and tensile properties (Et and UTS) of 2 by 10 No. 2 grade southern pine (Pinus spp.) lumber. A total of 285 lumber pieces were first nondestructively tested using longitudinal vibration (Director HM 200), transverse vibration (Metriguard E-computer), and proof-loading bending tests (Universal Instron Machine). Each specimen was then destructively tested in tension parallel to the grain to determine tension modulus of elasticity (Et) and ultimate tensile stress (UTS). Correlations between growth characteristics, physical, and mechanical properties were analyzed. Excellent correlative relationships between longitudinal and transverse dMOE with the elastic properties Eb, and Et were found. A strong correlation was also found between the elastic properties Eb and Et. The prediction of Eb was improved after adding density to the model. The estimation of UTS was also improved with the addition of density and a secondary nondestructive measurement. Nondestructive techniques are recommended to assess the mechanical properties of southern pine 2 by 10 lumber.
... Since the early days of humanity, wood has been a very important building material in meeting the necessary structural needs by using materials found in nature [1].Since timberis an anisotropic material, it is very di cult to obtain the desired cross-sectional dimensions in building elements [2,3].Wood, which is a renewable material, is subjected to a number of processes after the tree is cut down in the forest until it can be used structurally [4].These processes vary according to where the wood will be used in the structure and what purpose it will serve [5]. ...
In this study, it was aimed to improve the mechanical properties of laminated timber beams by using NovelHybrid Systems (Carbon Fiber Reinforced Polymer and Wire Rope). Reducing the cross-sectional area of the beam is important for the strength conditions required in large span systems with structural laminated wood material. Within the scope of this study, it is foreseen that the use of wood, which is an environmentally friendly and sustainable building element, will be made more economical and safe, instead of reinforced concrete and steel elements currently used to pass wide openings. Structural behavior of hybrid reinforced laminated timber beams was determined under the loading system.Experimental findings show that normal laminated timber beam (0N) has a maximum load of 14 kN and a deflection of 36 mm.On the other hand, the highest increase in the values of laminated beams reinforced with steel ropes was obtained with the (2N) reinforcement, with a maximum load of 38 kN and a displacement of 137mm.In this way, a load increase of 168% and a displacement increase of 275% compared to the reference sample were obtained. Since the steel rope-reinforced samples absorb the load, crack formation and transfer to the upper layers are prevented.3F beam specimen reinforced with CFRP and steel ropes obtained maximum load of 28 kN and a displacement of 152 mm. Compared to the reference sample, a load increase of 92% and a displacement increase of 14% were obtained. Consequently, the fabrics placed between the layers with CFRP prevented crack development and provided a significant interlayer connection.It has been observed that the fiber composite-reinforced wooden beams increase the load bearing capacity by more than 50% and exhibit a ductile behavior.The carbon fabrics placed between the laminated wooden beams with the innovative reinforcement system will not both disrupt the aesthetics and will reduce the effect of earthquake forces, and significant reductions can be achieved in the sections.
... Çok az inşaat malzemesi ahşabın çevresel faydalarına sahiptir. (Jiang F. vd., 2018;Falk, R. H., 2009). Bu bağlamda çevre dostu, sürdürülebilir yapısal ahşap malzeme olan çapraz lamine ahşap (CLT), birçok uygulamada beton, duvar ve çeliğe uygulanabilir bir alternatiftir. ...
... In addition, by-products generated in sawmills such as wood flour, chips, particles, sawdust, and fibers are used in production of high value wood panels not only adding value to the originally less valuable by-product but also reducing and managing wastes. Moreover, the porous nature of these by-products, in particular wood fibers and sawdust, can be used to encapsulate BPCMs to produce energy smart wood-based panels for passive energy storage in buildings [5][6][7][8][9]. ...
... Wood, which is a renewable material, is subjected to a number of processes after the tree is cut down in the forest until it can be used structurally [4]. These processes vary according to where the wood will be used in the structure and what purpose it will serve [5]. ...
In this study, it was aimed to improve the mechanical properties of laminated timber beams by using Novel Composite Systems (Carbon Fiber Reinforced Polymer and Wire Rope). Reducing the cross-sectional area of the beam is important for the strength conditions required in large span systems with structural laminated wood material. Within the scope of this study, it is foreseen that the use of wood, which is an environmentally friendly and sustainable building element, will be made more economical and safe, instead of reinforced concrete and steel elements currently used to pass wide openings. Structural behavior of hybrid reinforced laminated timber beams was determined under the loading system. Experimental findings show that normal laminated timber beam (0N) has a maximum load of 14 kN and a deflection of 36 mm. On the other hand, the highest increase in the values of laminated beams reinforced with steel ropes was obtained with the (2N) reinforcement, with a maximum load of 38 kN and a displacement of 137mm. In this way, a load increase of 168% and a displacement increase of 275% compared to the reference sample were obtained. Since the steel rope-reinforced samples absorb the load, crack formation and transfer to the upper layers are prevented. 3F beam specimen reinforced with CFRP and steel ropes obtained maximum load of 28 kN and a displacement of 152 mm. Compared to the reference sample, a load increase of 92% and a displacement increase of 14% were obtained. Consequently, the fabrics placed between the layers with CFRP prevented crack development and provided a significant interlayer connection. It has been observed that the fiber composite-reinforced wooden beams increase the load bearing capacity by more than 50% and exhibit a ductile behavior. The carbon fabrics placed between the laminated wooden beams with the innovative reinforcement system will not both disrupt the aesthetics and will reduce the effect of earthquake forces, and significant reductions can be achieved in the sections.
... In addition, wood has the highest value of raw material consumed. Wood products produced from trees range from a minimally processed home building site to a highly processed wood composite manufactured in large production plants (Falk, 2009). Wood is a renewable resource. ...
... These types of degradation limit the utility of wood in high moisture environments. An improved understanding of transport mechanisms would accelerate the development of more environmentally friendly wood preservation treatments and improved resistance to degradation, thereby expanding the market for sustainable wood construction materials (Falk, 2009). Wood tissue exhibits a hierarchical structure which provides structural support while enabling transport of water and nutrients (Arzola-Villegas et al., 2019). ...
Secondary plant cell walls are composed of carbohydrate and lignin polymers, and collectively represent a significant renewable resource. Leveraging these resources depends in part on a mechanistic understanding for diffusive processes within plant cell walls. Common wood protection treatments and biomass conversion processes to create biorefinery feedstocks feature ion or solvent diffusion within the cell wall. X-ray fluorescence microscopy experiments have determined that ionic diffusion rates are dependent on cell wall hydration as well as the ionic species through non-linear relationships. In this work, we use classical molecular dynamics simulations to map the diffusion behavior of different plant cell wall components (cellulose, hemicellulose, lignin), ions (Na+, K+, Cu2+, Cl-) and water within a model for an intact plant cell wall at various hydration states (3-30 wt% water). From these simulations, we analyze the contacts between different plant cell wall components with each other and their interaction with the ions. Generally, diffusion increases with increasing hydration, with lignin and hemicellulose components increasing diffusion by an order of magnitude over the tested hydration range. Ion diffusion depends on charge. Positively charged cations preferentially interact with hemicellulose components, which include negatively charged carboxylates. As a result, positive ions diffuse more slowly than negatively charged ions. Measured diffusion coefficients are largely observed to best fit piecewise linear trends, with an inflection point between 10 and 15% hydration. These observations shed light onto the molecular mechanisms for diffusive processes within secondary plant cell walls at atomic resolution.
... Research by Falk (2009) focused on the sustainability of wood and its application in constructions based on wood. Based on the analyses in the research, one of the conclusions is that "the green building movement is here to stay and will undoubtedly grow in the future. ...
Population growth sharply increases demand for readily available and affordable housing. As people spend a greater proportion of their lives indoors (chances of another pandemic increase with global warming), the energy necessary for construction materials, construction, maintenance, reconstruction, waste management and other services associated with housing becomes responsible for nearly half of the carbon released worldwide. There is a broad consensus that wood constructions could be an environmentally favorable instrument, as wood is the most reliable mechanism for carbon sequestration. Therefore, increasing the efficiency of wood constructions is a highly important matter. On-site and off-site construction was robustly assessed in terms of cost effectiveness. It is firstly demonstrated that off-site preproduction of components results in a range of benefits due to reduced labor (the main factor determining prices and time) and reduced use of materials and services. It is also demonstrated that component preproduction allows reducing the construction costs of wood houses by 6% and construction time by 20%. In other words, off-site preproduction of components for the construction of wood buildings improves their competitiveness and brings them closer to the very few profitable methods of carbon sequestration.
Graphic abstract
... Both materials have their advantages and disadvantages. Combining them and ensuring their composite action makes it possible to reduce the disadvantages of these materials and obtain a structure with such benefits as a lower self-weight and better sound insulation than concrete structures, and greater stiffness and load-bearing capacity than timber structures [1][2][3][4][5][6][7]. ...
With the growing importance of the principles of sustainable construction, the use of load-bearing timber-concrete composite structures is becoming increasingly popular. Timber-concrete composite offers wider possibilities for the use of timber in construction, especially for large-span structures. The most significant benefit from combining these materials can be obtained by providing a rigid connection between the timber and concrete layers, which can be obtained by the adhesive timber-to-concrete connection produced by the proposed stone chips method. A sustainable solution involves the abandonment of steel longitudinal reinforcement. The use of such a solution in practice is often associated with fears of a fragile collapse. Therefore, the issue of how to increase the safety factor of the proposed material is topical now. The experimental investigation is made to determine the effect of synthetic fibre use on timber-concrete composite behaviour by testing a series of timber-concrete composite specimens with and without fibres in the concrete layer. The obtained results show that adding 0.5 % of synthetic macro fibres allows to abandon the use of longitudinal steel reinforcement and prevents the formation of large cracks in concrete and the disintegration of the concrete layer in case of collapse.
... Çok az inşaat malzemesi ahşabın çevresel faydalarına sahiptir. (Jiang F. vd., 2018;Falk, R. H., 2009). Bu bağlamda çevre dostu, sürdürülebilir yapısal ahşap malzeme olan çapraz lamine ahşap (CLT), birçok uygulamada beton, duvar ve çeliğe uygulanabilir bir alternatiftir. ...
... Managing the trade-offs between carbon sequestration, wood production, and water security will require an understanding of the regional relationship between forests, productivity, and water use. In terms of water footprint and carbon sequestration capability, wood stands over other structural materials (see Falk (2009) ...
This paper reviews the current knowledge of hydrological processes in Chilean temperate forests which extend along western South America from latitude 29° S to 56° S. This geographic region includes a diverse range of natural and planted forests and a broad sweep of vegetation, edaphic, topographic, geologic, and climatic settings which create a unique natural laboratory. Many local communities, endangered freshwater ecosystems, and downstream economic activities in Chile rely on water flows from forested catchments. This review aims to (i) provide a comprehensive overview of Chilean forest hydrology, to (ii) review prior research in forest hydrology in Chile, and to (iii) identify knowledge gaps and provide a vision for future research on forest hydrology in Chile. We reviewed the relation between native forests, commercial plantations, and other land uses on water yield and water quality from the plot to the catchment scale. Much of the global understanding of forests and their relationship with the water cycle is in line with the findings of the studies reviewed here. Streamflow from forested catchments increases after timber harvesting, native forests appear to use less water than plantations, and streams draining native forest yield less sediment than streams draining plantations or grassland/shrublands. We identified 20 key knowledge gaps such as forest groundwater systems, soil-plant-atmosphere interactions, native forest hydrology, and the effect of forest management and restoration on hydrology. Also, we found a paucity of research in the northern geographic areas and forest types (35-36°S); most forest hydrology studies in Chile (56%) have been conducted in the southern area (Los Rios Region around 39-40° S). There is limited knowledge of the geology and soils in many forested areas and how surface and groundwater are affected by changes in land cover. There is an opportunity to advance our understanding using process-based investigations linking field studies and modeling. Through the establishment of a forest hydrology science “society” to coordinate efforts, regional and national-scale land use planning might be supported. Our review ends with a vision to advance a cross-scale collaborative effort to use new nation-wide catchment-scale networks Long-term Ecosystem Research (LTER) sites, to promote common and complementary techniques in these studies, and to conduct transdisciplinary research to advance sound and integrated planning of forest lands in Chile.
... In addition, by-products generated in sawmills such as wood flour, chips, particles, sawdust, and fibers are used in production of high value wood panels not only adding value to the originally less valuable by-product but also reducing and managing wastes. Moreover, the porous nature of these by-products, in particular wood fibers and sawdust, can be used to encapsulate BPCMs to produce energy smart wood-based panels for passive energy storage in buildings [5][6][7][8][9]. ...
... As resource availability declines and the demand for the resource increases in today's modern industrialized world, the need to explore new opportunities in the near future is important for sustainable building materials (Meadows et al. 1992). Wood, for example, has recently gained popularity in the green building community because of its environmentally beneficial characteristics: wood is promoted as renewable, biodegradable, sequestering carbon from the atmosphere, low in embodied energy, and creating less pollution in production than steel or concrete (Falk 2009). Bamboo has similar environmental characteristics (Lee et al. 1994;Van der Lugt et al. 2006;Rittironk and Elnieiri 2008;Nath et al. 2009). ...
Bamboo is one of the fastest growing plants and has mechanical properties similar to timber. The main reasons for the popularity of bamboo in construction can be attributed to its low cost, local availability, and adequacy of simple, local tools, and skills for fabrication. Application of bamboo in construction is, however, normally limited to low-cost housing and temporary structures due to several factors including irregular shapes, hollow circular cross sections, and durability issues. This report presents the results of an investigation into production of an engineered bamboo lumber product. Bamboo culms were cut into smaller strands and were re-constituted into rectangular sections by gluing and pressing at 140 °C to 145 °C. This approach overcomes the presence of the inherent hollow core and randomizes the inter-nodes and other growth characteristics found in bamboo. The reconstituted bamboo strand lumber (RBSL) was developed using crushed Bambusa bambos species and phenol formaldehyde resin. The physical and mechanical properties of reconstituted bamboo strand lumber were evaluated as per IS 1734 (1983). From the results it was found that the BSL can be used as an alternate to timber to meet Sustainable Development Goals (SDGs) for building applications that will effectively transform the world.
... Particular attention has been paid to reducing the amount of carbon emitted by buildings (Jeong et al. 2012), which account for approximately 25% of total worldwide carbon emissions (Cho et al. 2019). Wood, as a sustainable resource, has re-emerged as an attractive building material, and demand for wood construction material is steadily increasing (Falk 2009). If new construction of buildings in Europe is planned to be wooden, carbon storage is equal to maximum 47% of European cement industry CO 2 emissions (Amiri et al. 2020). ...
The article deals with the effects of bulk density on thermal conductivity in specimens of 15Korean woods (Zelkova serrata, Pinus densiflora, Cornus controversa, Betula schmidtii, Betula platyphylla var. japonica, Ginkgo biloba L.,Cedrela sinensis A. Juss., Fraxinus mandshurica, Ulmus davidiana var. japonica, Prunus sargentii Rehder, Paulownia tomentosa (Thunb.) Steud., Larix kaempferi (Lamb.) Carrière, Robinia pseudoacacia, Kalopanax septemlobus and Tilia amurensis).The results of this study were compared with previous studies performed on wood specimens fromChina, India, and Turkey. Consistent with these previous studies, bulk density and thermal conductivity were positively correlated in Korean woods, and a simple regression model with a very high correlation of R2(94%) was obtained. Interestingly, we observed some variation between our simple regression models and those generated by previous researchers who had examined non-Korean woods.
... In order to address the mentioned problems related to non-renewable construction materials, more attention lays on engineered wood elements as bio-based, renewable, sustainable and recyclable material to replace currently used traditional materials in modern single and multistory building constructions [5]. Manufacturing of wooden-based construction materials demands less energy compared to steel and concrete and the wastes are recycable [7]. ...
Wood impregnated with a multicomponent mixture of fatty acids as a bio-based phase change material (BPCM) to improve its thermal characteristics was studied. The studied wood/BPCM composites can be used as internal elements in buildings for energy storage. Scots pine and beech sapwood were impregnated with a multicomponent mixture of linoleic acid and coconut oil fatty acids at a ratio of 20:80. Leakage test was conducted and revealed that the maximum leakage for pine and beech were 9 and 8%, respectively. Light microscopy was employed to demonstrate the distribution of the BPCM in the wood structure. Rays in both pine and beech wood served as pathways for impregnation of the BPCM to partly fill the tracheid lumens (pine) and vessels (beech). Thermal characterization of the studied samples employed T-history and DSC methods, concluding that the impregnated wood had significant thermal mass, ability to store excessive energy in terms of latent heat and keep the temperature constant for long time. The specific heat capacity of the impregnated samples was 4–5 J g ⁻¹ K ⁻¹ i.e., higher than that of the untreated control samples of ca. 2 J g ⁻¹ K ⁻¹ . The thermal conductivity of the samples before and after the impregnation was measured using heat flow meter method and the results showed that the untreated beech wood had higher thermal conductivity compared to pine and the parameter improved when the cell lumens were filled with the BPCM. Scots pine wood with to 80% mass percentage gain (MPG) after impregnation demonstrated an increment in thermal conductivity of 33% while Scots pine and beech with 43 and 38% MPG demonstrated an increase of the conductivity with 8 and 11%, respectively.
... Material substitution: Using other sustainable basic materials such as wood in the building sector (Falk, 2009) or clinker substitutes (IEA, 2018b) can reduce the demand for emission and energyintensive basic materials like cement or steel. ...
The industrial processes we have used for producing basic materials over the last centuries are unsuitable for an economy with a net-zero carbon footprint. Basic materials like steel, cement, aluminium and (petro)chemicals are the building blocks of our industrialised societies, but today their production is highly energy and emission-intensive. There is no other alternative. These industries need to decarbonise over the next decades for keeping global warming below 2°C. However, the implications of this transition for the industry, our energy systems and society are little understood.
This thesis asks how this transition can take place by exploring the technical, economic, and regulatory dimensions of decarbonising the energy-intensive basic material sector. By following a multidisciplinary approach, the thesis looks upon these different dimensions separately, identifying propositions that characterise the industrial transition and help us understand its implications for our energy systems.
The first part of the thesis studies technology options for climate-friendly basic material production in different industries and evaluates their cross-sectorial significance. Findings highlight the challenge of reducing emissions linked to the high thermal energy demand required to produce most basic materials and process emissions originating from the chemical transformation of naturally occurring resources to basic materials. Decarbonisation across all industries requires breakthrough technologies that are not available on a commercial scale.
Today´s conventional production technologies are highly standardised. They rely primarily on fossil fuels, obtaining basic materials in high quantities while keeping energy costs low. However, climate-friendly breakthrough technologies mark a shift from fossil fuels to low-emission alternatives. Therefore, the second part of this thesis studies the functioning of future electricity markets and explores the implication of decarbonising energy systems for industrial consumers. Future energy markets should be designed to ensure the emission avoidance, affordability, and adequacy of energy for industrial consumers.
Higher costs for low-emission energy sources or potentially higher energy demand to avoid emissions make climate-friendly basic material production more expensive than conventional processes. Breakthrough technologies require a regulatory framework to support the transition. The third part of this thesis demonstrates how different policies are needed to kick-start the transition, create markets for climate-friendly materials and ensure long-term climate neutrality.
Finally, the last part of this thesis reflects upon the propositions that characterise the transition´s technological, economic, and regulatory dimensions and argues that models to study the transition need to incorporate the three dimensions sufficiently. Since energy-system models and bottom-up approaches are insufficient, a new sector-specific modelling approach is necessary. The thesis introduces the conceptual model TRANSid (Transition towards Industrial Decarbonisation) to address this modelling gap. It uses a simplified case study to demonstrate how the conceptual model could be translated into a mathematical formulation.
The thesis concludes with various recommendations about the future research needs to study industrial decarbonisation across the technological, economic and policy dimensions.
... One of our best allies in solving the climate crisis due to its potential eco-friendly properties, wood is at the forefront of tackling European climate policy [34][35][36][37]. Furthermore, due to its significantly lower carbon footprint and potential cost-effectiveness compared with conventional materials such as reinforced concrete and steel, and numerous positive effects on the environment combined with technological advances [38][39][40][41]. Besides this, as it is well known, from an architectural point of view, wooden buildings are thought to have the potential to generate a more pleasant, warm, and natural environment. ...
Finnish urban settlements are in the age of restoration, and the suburbs need improvements in Finland. In this sense, wooden facade renovation and additional floor construction are viable and sustainable solutions for this development in the Finnish context. This chapter focuses on these important applications from the Finnish residents' perspective as ecologically sound engineering solutions through a survey. In doing so, the challenges of facade renovation, as well as the benefits of additional floor construction, were presented. The main purpose of the survey was to get the opinions of the residents, find out which variables are important, make inferences for the planning and improvement of such areas, and determine what will be emphasized in the sustainable suburban development of the future. Therefore, the results were based on this empirical approach-survey-but further research such as energy analysis, wood-based facade renovation, and additional floor solutions will be done as part of other studies. It is believed that this study will contribute to the use of sustainable materials and decarbonization of buildings as well as zero energy building (nZEB) to overcome the challenges posed by climate change by the diffusion of wood in the renovation of buildings.
... The concept of eco-buildings, sound construction methods and material selection is gaining attention due to the growing concern for the environment [2][3][4] . Wood has been one of the main building materials throughout the history of mankind and is considered a renewable source [5][6][7] . Fire safety is especially important in construction, and wood is a fire hazardous material. ...
... Wood is a sustainable and renewable building material with a low carbon impact [1][2][3], favourable seismic performance [4,5] and ability to self-protect against fire [6][7][8]. These are some of the most relevant reasons to explain the steady increase in the use of this material in the construction and building sector [9]. ...
In the last decades the use of wood as a construction material has been steadily increasing. Among the main reasons behind this, are its renewable resource nature and its low environmental footprint. In this context, one of the main challenges faced by engineers during the design process is the knowledge and characterization of wood’s thermo-mechanical properties. This is related to the large morphological variations present at the microstructural level, that lead to a wide scatter of the macroscopic properties. To circumvent this issue, in this work a multiscale modelling strategy based on asymptotic homogenisation is proposed. The model is based on the hierarchical nature of wood and incorporates the three material scales generally identified in soft woods: (i) the microfibril scale, (ii) the wood cell scale, and (iii) the growth ring scale. The effective thermo-mechanical macroscopic properties are obtained by sequentially applying the homogenisation procedure from the microfibril scale all the way up to the macroscopic scale. The model is employed here to investigate the thermo-mechanical response of radiata pine grown in Chile. To determine values of the microstructural parameters that yield macroscopic properties consistent with those observed experimentally, a parameter identification strategy is proposed. The latter considers four elements: an existing experimental database on timber boards density and bending tests, the multiscale model, a timber board bending test finite element model and a genetic algorithm for the optimization procedure. With the resulting microstructural parameters the model is then used to estimate the effective elastic, thermal, and thermo-mechanical properties of radiata pine wood. When compared with measured experimental data and typical experimental values found in the literature, the numerical estimates demonstrate the model predicting capabilities.
The full article can be found in: https://authors.elsevier.com/a/1e7zS3O1E1MtnB
... Its economic benefit is not farfetched as it can be combined with other elements to form a composite. Its renewability will be possible if the policy of harvesting and planting is followed [26]. Fig. 1 shows recycled waste from agro-industrial waste. ...
Most of the building ceiling tiles used today from studies, such as polyvinyl chloride (PVC) composite ceilings, cardboard, plywood, particleboard, are flame friendly. Except for asbestos, which is confirmed to emit asbestosis, cancer from asbestos; already warned by the Environmental Protection Agencies and other health standard organizations. Studies have shown inherent harmful elements associated with the use of PVC Ceiling composite, plant-based ceiling, and asbestos, which propagate noxious emission at the instance of fire; their widespread use is quite enormous. The noxious behaviour during an inferno is a representation of the elemental make-up of these ceiling materials. Moreover, their vulnerability due to emission and combustion threat call for alternative materials with eco-friendly constituents for building ceiling applications. Problems associated with these building ceilings during fire include noxious gaseous emissions; fuel for the flame from ignition from other roof frame structures; after flame effect of inhaling poisonous gasses against the recommended exposure limit of 35 ppm by the World Health Organization (WHO). Flame retardance is credited to asbestos. However, for other ceiling tiles, some of the challenges of high heat flux, high thermal conductivity, and combustibility tendencies, are still current issues. The undesirable side effects of using ceiling tiles have necessitated a replacement with suitable flame retardant and eco-friendly influences. This is made to bear by appropriate material selection and by employing industrial wastes and agricultural wastes coupled with suitable binders to solve flame propagation challenges. It is, therefore, necessary to develop a flame retardant ceiling composite that will solve the identified anomalies in the existing ceiling tiles in the market in building industries. The developed materials are tested for thermal and emission characteristics to ascertain their integrity by employing advanced test equipment. The result shows that there are low values in thermal conductivity of the developed building ceiling samples. Sample 2 has the lowest value compared to the developed and existing ceiling tiles, much < 0.0802 W/mK, which is a desirable property in ceiling application. Low thermal diffusivity is required to suppress flame propagation. This is exhibited by sample 1, with a value of 0.85 × 10⁻⁸ m²/s as the lowest among developed ceiling samples The result showed null and negligible SO2 detection for all samples. The three samples' time to attain pre-set temperature varies in the ascending order of sample 1 at 24 minutes, sample 3 at 37 minutes, and sample 2 at 42 minutes. Sample 3, 0.6Aldr0.34Cmt0.05G0.01OBS; Sample 2, 0.6Aldr0.32Cmt0.05G0.03OBS and sample 1, 0.6Aldr0.3Cmt0.05G0.05OBS are in the order in terms of safe emission characteristics while sample 2 ranks best in terms of flame retardancy.
This study has established that the developed building ceiling composite material is flame retardant capable of preventing fire propagation, unlike the flammable polyvinyl chloride (PVC) ceiling composite. The developed building ceiling composite can minimize the emission of harmful elements in the make-up of the ceiling, as revealed in the results. The tiles are alternative to both noxious PVC and asbestos ceiling tiles. Oil beanstalk is a novel material introduced as a reinforcement to the developed composite. The manufacturing industries should explore materials with excellent eco-friendly flame retardant constituents to encourage sustainable building production.
Wood is a versatile raw material that can be used in many different ways-from paper and packaging to construction. In addition, wood products can be reused and recycled when their original use becomes obsolete. An important renewable resource is wood biomass, which is mostly derived from forest residues, wood processing residues or construction and municipal waste. These materials can be processed and reused, providing a more environmentally friendly alternative. Although recovery rates are relatively low, environmental awareness is increasing. Companies are investing in optimising technological and logistical processes, while at the same time reducing their environmental impact. These efforts can reduce a company's costs and also reduce environmental waste. The aim of this paper is to characterise residual wood biomass, its forms, sources and uses, and to identify reverse supply chain and their main challenges. For the needs of the paper, research was conducted using Focus Group Interviews (FGIs). We carried out three direct structured group interviews using questionnaires with managers from companies dealing with residual wood biomass.
Reducing the water absorption of wood is important as less permeability to water implies enhanced resistance against wood-decaying organisms and is mechanically stable. Many preservatives are in current practice, configuring which type of preservative is more effective on which species of wood requires an effort. Hence, this can be evaluated by water absorption of differently treated wood. Thus, this review aims to focus on the phenomenon of water absorption on treated wood and build an argument on the impact of chemical modification on water absorption. This study describes the practical applications of wood treatment techniques and how they could be integrated to solve the problematic areas in wood–moisture relations. The initial phase of the study overview the current level of knowledge on essential features of moisture in wood and attempts to identify the existing knowledge gaps in the field of the wood industry. This review is conducted by referring to 85.5% journals, 8.4% conference papers, 3.05% electronic books, and 3.05% others. The review identifies more research ought to be conducted about chemicals that would reduce hygroscopicity and provide durability with minimum toxicity to nature. Such knowledge might be applied to a variety of sectors of research, including how to improve decomposition resistance, how to improve the performance of moisture-induced wooden actuators, and combining various revelations of moisture in wood with the introduction of specific chemical alterations. Regulating the spatial distribution should provide a unique overview of the wood–water reactions. Therefore, the resultant innovative ideas would be useful in related disciplines such as polymer science and the construction industry.
The environmental impact of fossil-based materials in the building industry and significant energy consumption in residential buildings have urged new research areas in using bio-based, renewable and sustainable materials for production of energy smart bio-based envelopes for building applications. This can be achieved by incorporation of bio-based phase change materials (BPCMs) in wood materials for energy storage in residential buildings. In this thesis, an attempt was made to develop a new BPCM based on coconut oil (CO). The oil was converted into free fatty acids (CoFA) by alkaline saponification and mixed with oleic (OA) and linoleic (LA) acid in various proportions to obtain stable compositions with desirable working temperatures. The prepared mixtures were visually, chemically and thermally studied confirming that the combination of CoFA/LA 20:80 was the most suitable combination and used further as BPCM (xLA= 0.2). The new system melts uniformly at 24.8 ºC, and freezes at two points 18 and 22 ºC, with latent heat of fusion of 100 J/g, heat capacity of around 5 J/g K, thermal conductivity of 0.2 W/m K, in liquid and 0.35 W/m K in solid phase and a good thermal stability after 700 intensive cooling/heating cycles. BPCM (xLA= 0.2) was incorporated by impregnation in solid untreated Scots pine and beech and thermally modified pine (TMP), beech (TMB) and spruce (TMS) wood. The impregnability and intensive leakage tests revealed the positive effect of thermal modification on improving permeability and decreasing leakage. A microscopy study showed that rays in both pine and beech were the main pathway for impregnation. The specific heat capacity of unmodified and thermally modified samples before impregnation were similar at around 2 J/g K, which after impregnation, increased to 4-5 J/g K. The introduction of BPCM (xLA= 0.2) led to improved thermal mass and thermal conductivity of the impregnated samples. The latent heat of fusion for impregnated samples was proportional to the amount of BPCM (xLA= 0.2) in the samples. Mold tests showed that BPCM (xLA= 0.2) encapsulated in Chemical and physical incorporation of bio-molecules into wood materials for energy storage studied thermally modified wood species is less susceptible to mold discoloration compared to unmodified samples. A bio-composite consisting of wood particles impregnated with ethyl palmitate ester (EP) as BPCM and a bio-binder was studied. An optimal proportion of 25 % EP was used in the composite to minimize leakage. The composite was thermally stable to a temperature of 200 ºC. The composite thermal characteristics are similar to solid wood impregnated with BPCM. A benefit of the bio-composite was the added-value to less-valuable industrial bi-products involved in the production of energy smart bio-composite for building application, as well as possibility to produce different profiles.
Different forms of construction materials (e.g., paints, foams, and boards) dramatically improve the quality of life. With the increasing environmental requirements for buildings, it is necessary to develop a comprehensive sustainable construction material that is flexible in application and exhibits excellent performance, such as fireproofing and thermal insulation. Herein, an adjustable multiform material strategy by water regulation is proposed to meet the needs of comprehensive applications and reduce environmental costs. Multiform gels are constructed based on multiscale cellulose fibers and hollow glass microspheres, with fireproofing and thermal insulation. Unlike traditional materials, this multiscale cellulose-based gel can change forms from dispersion to paste to dough by adjusting its water content, which can realize various construction forms, including paints, foams, and low-density boards according to different scenarios and corresponding needs.
Objective:In our study, we analyzed the most cited 101 articles on nutrition from the intensive care literature.Materials and Methods:Using an advanced mode of the Web of Science (WOS), the keys “WC = Critical Care Medicine and TS = nutr* or WC = Critical Care Medicine and TI = nutr* or WC = Nutrition & Dietetics and TS = intensive care or WC = Nutrition & Dietetics and TI = intensive care or WC = Nutrition & Dietetics and TS = critical care or WC = Nutrition & Dietetics and TI = critical care” were used to identify the articles on June 2021.Results:From 1975 to the present a total of 7,093 articles related to nutrition of critical care were published in the WOS. The most cited article received 1,011 citations; the least cited articles received 166 citations. The average number of citations was determined as 287.77±178.57. The mean annual citation number was 21.86±35.46. The most cited article was by McClave, Stephen et al. “Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Adult Critically Ill Patient: Society of Critical Care Medicine and American Society for Parenteral and Enteral Nutrition.” The three most cited areas of critical care nutrition articles focused on “Enteral Nutrition,” “Immune-nutrition,” and “Outcomes of the Nutrition” and were conducted in 20.8%, 20.8%, and 17.8% studies, respectively. The three most frequently journals in the top 101 position were Critical Care Medicine (43.6%), Intensive Care Medicine (10.9%), Clinical Nutrition (7.9%), and the Journal of Parenteral and Enteral Nutrition (7.9%) happened. The USA (38.6%), Canada (%12.9), and England (7.9%) took the top three places for authors. A total of 36.6% of the authors were from the European continent and 63.4% were from outside the European continent. No significant difference was found between the continent of authors, the journal’s index, the total number of citations and the annual average number of citations.A significant relationship was found between the year of publication of the article, the journal in which it was published, the country of the journal in which it was published, continent of the journal, type of the study, the subject area, number of citations per year, and between the type of study and the total number of citations of the article (p
Knowledge of carbon exchange between the atmosphere, land and the oceans is important, given that the terrestrial and marine environments are currently absorbing about half of the carbon dioxide that is emitted by fossil-fuel combustion. This carbon uptake is therefore limiting the extent of atmospheric and climatic change, but its long-term nature remains uncertain. Here we provide an overview of the current state of knowledge of global and regional patterns of carbon exchange by terrestrial ecosystems. Atmospheric carbon dioxide and oxygen data confirm that the terrestrial biosphere was largely neutral with respect to net carbon exchange during the 1980s, but became a net carbon sink in the 1990s. This recent sink can be largely attributed to northern extratropical areas, and is roughly split between North America and Eurasia. Tropical land areas, however, were approximately in balance with respect to carbon exchange, implying a carbon sink that offset emissions due to tropical deforestation. The evolution of the terrestrial carbon sink is largely the result of changes in land use over time, such as regrowth on abandoned agricultural land and fire prevention, in addition to responses to environmental changes, such as longer growing seasons, and fertilization by carbon dioxide and nitrogen. Nevertheless, there remain considerable uncertainties as to the magnitude of the sink in different regions and the contribution of different processes.
Policymakers, program managers, and landowners need information about net terrestrial carbon sequestration in forests, croplands, grasslands, and shrublands to understand the cumulative effects of carbon trading programs, expanding biofuels production, and changing environmental conditions in addition to agricultural and forestry uses. Objective information systems that establish credible baselines and track changes in carbon storage can provide the accountability needed for carbon trading programs to achieve durable carbon sequestration and for biofuels initiatives to reduce net greenhouse gas emissions. A multi-sector stakeholder design process was used to produce a new indicator for the 2008 State of the Nation's Ecosystems report that presents metrics of carbon storage for major ecosystem types, specifically change in the amount of carbon gained or lost over time and the amount of carbon stored per unit area (carbon density). These metrics have been developed for national scale use, but are suitable for adaptation to multiple scales such as individual farm and forest parcels, carbon offset markets and integrated national and international assessments. To acquire the data necessary for a complete understanding of how much, and where, carbon is gained or lost by U.S. ecosystems, expansion and integration of monitoring programs will be required.
This paper presents the Life-Cycle Assessment (LCA) of alternative building materials from forest resource regeneration or mineral extraction through product manufacturing, the assembly of products in constructing a residential home, occupancy and home repairs, and the eventual disposal or recycle. A unique feature of this study's LCA framework is that temporal distribution of events and associated environmental effects during the seed to demolition life cycle were considered by extending the scope to include forest growth through to demolition of the builidng. Our approach was to first conduct LCIs that quantified the energy, resource use, and emissions associated with a particular product, service, or activity. We followed this activity with the assessment of the house, and investigated the potential environmental consequences of energy and resource consumption and waste emissions. Finally we identified improvement opportunities for future research.
Criterion 5 Contribution of Forest Ecosystems to the Total Global Carbon Budget, Including Absorption and Release of Carbon In: Data report: A supplement to the national report on sustainable forests –
- L Heath
- J Smith
Heath, L. and J. Smith. 2004. Criterion 5, Indicator 27: Contribution
of Forest Ecosystems to the Total Global Carbon Budget,
Including Absorption and Release of Carbon. In: Data report:
A supplement to the national report on sustainable forests –
2003, D. Darr, coord. FS-766A. USDA, Washington, DC. p. 7.
Beginners Guide to Third-Party Forest Certification: Shining a Light on the Canadian Standards Association (CSA) Report of the Dovetail Partners
- K Fernholz
- J Howe
- P Guillery
- J Bowyer
Fernholz, K., J. Howe, P. Guillery, and J. Bowyer. 2005. Beginners
Guide to Third-Party Forest Certification: Shining a Light on
the Canadian Standards Association (CSA). Report of the
Dovetail Partners, Inc. www.dovetailinc.org.
EPA) Energy Trends in Selected Manufacturing Sectors: Opportunities and Challenges for Environmentally Preferable Energy Outcomes
Environmental Protection Agency (EPA). 2007. Energy Trends in
Selected Manufacturing Sectors: Opportunities and
Challenges for Environmentally Preferable Energy Outcomes.
Biomass Energy Consumption in the Forest Products Industry
- B Murray
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- M Ross
- T Holloway
- S Patil
Murray, B., R. Nicholson, M. Ross, T. Holloway, and S. Patil. 2006.
Biomass Energy Consumption in the Forest Products
Industry. U.S. Dept. of Energy, RTI International.
Carbon in U.S. Forests and Wood Products State by State Estimates
- R Birdsey
- G Lewis
Birdsey, R. and G. Lewis. 2002. Carbon in U.S. Forests and Wood
Products, 1987–1997: State by State Estimates. USDA Forest
Service, General Technical Report GTR-NE-310.
United Nations Economic Commission for Europe Forest Products Annual Market Review
United Nations Economic Commission for Europe (UNECE). 2008.
United Nations Economic Commission for Europe/Food and
Agriculture Organization of the United Nations, Forest
Products Annual Market Review 2007–2008. www.unece.org/
trade/timber.
Wood Products and Carbon Protocols: Carbon Storage and Low Energy Intensity Should be Considered
- J Bowyer
- S Bratkovich
- A Lindberg
- K Fernholz
Bowyer, J., S. Bratkovich, A. Lindberg, and K. Fernholz. 2008.
Wood Products and Carbon Protocols: Carbon Storage and
Low Energy Intensity Should be Considered. Report of the
Dovetail Partners, Inc. www.dovetailinc.org.
Contribution of Forest Products to the Global Carbon Budget In: Data report: A supplement to the national report on sustainable forests –
- L Heath
- K Skog
Heath, L. and K. Skog. 2004. Criterion 5, Indicator 28: Contribution
of Forest Products to the Global Carbon Budget. In: Data
report: A supplement to the national report on sustainable
forests – 2003, D. Darr, coord. FS-766A. USDA, Washington, DC.
p. 10.
Beginners Guide to Third-Party Forest Certification: Shining a Light on the Programme for the Endorsement of Forest Certification schemes (PEFC) Report of the Dovetail Partners
- K Fernholz
- J Howe
- P Guillery
- J Bowyer
Fernholz, K., J. Howe, P. Guillery, and J. Bowyer. 2004. Beginners
Guide to Third-Party Forest Certification: Shining a Light on
the Programme for the Endorsement of Forest Certification
schemes (PEFC). Report of the Dovetail Partners, Inc.
www.dovetailinc.org.