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Wood is a renewable resource that has been used as a material in appearance products for years. Despite its acceptable mechanical resistance, different modification processes were developed to enhance wood’s hardness and make it an even more durable material. Impregnating wood pores with monomers under vacuum-pressure cycle is a common method for that purpose. However, most implemented processes are long and mostly submerge wood into a monomer formulation (Bethell’s full-cell process). For that, they can be considered wasteful on the quantity of materials used, energy consumed and on process duration. The objective of this paper was to evaluate the parameters that influence the penetration of monomers into the tangential surface of Yellow birch (Betula alleghaniensis Brit.) samples. The analyzed factors were the monomer formulation’s viscosity, the surface temperature, the vacuum level applied to the process, the anatomy of samples, and the absorption time. After impregnation, the weight gain of the samples was calculated. Monomer penetration depth was calculated and visualized using density profiles and micro X-ray tomography imaging. Results showed that using a low viscosity monomer formulation allied to a certain level of vacuum and absorption time can considerably increase the impregnation into the wood.

Filling wood cells with polymeric materials offers great opportunities to improve wood strength. Some applications, such as flooring, may require densification on one side of the material only. Yellow birch (Betula alleghaniensis Britt.), sugar maple (Acer saccharum Marsh.) and red oak (Quercus rubra L.) were surface densified through lateral chemical impregnation of monomers under vacuum followed by in situ electron beam polymerization. Lateral impregnation led to low mean chemical retention of 4% for sugar maple, 11% for red oak and 12% for yellow birch. X-ray densitometry and microtomography revealed an asymmetric density profile comparable to mechanically surface densified wood due to polymer-filled vessels. Scanning electron microscopy images showed presence of polymer-filled fibers beneath the surface. Brinell hardness of all species increased significantly compared to untreated wood. Low chemical retention significantly improved hardness due to localized polymer beneath the surface. Density profile characteristics were extracted from densitometry curves and correlated to hardness. Deep monomer penetration was more favorable to hardness than high surface density peak.

PurposeThe housing construction industry is one of the most lucrative sectors for developed countries. However, homebuyers are often vulnerable when left with latent building defects in their new-build house. Many nations have thus implemented new home warranty schemes to protect consumers and stimulate residential production. These warranty programs vary excessively from state to state given the distinct nature of environments. Previous studies have attempted to compare one with another but did not apply a consistent comparative method when doing so. Therefore, the purpose of this study is to identify the characteristics defining a new home warranty and to develop a standardised comparative framework.Design/methodology/approachAfter evaluating the characteristics outlined in multiple home warranty programs, a qualitative content analysis method was used to establish coding, categories and themes in order to create the framework. The methodology relied mostly on cross-referencing from academic papers, methodical reviews, government documents and professional consultant reports.FindingsThis paper reviewed warranty schemes from six countries: Canada, United Kingdom, Australia, Japan, France and Malaysia. The findings suggest that home warranty programs are defined by five main themes: political involvement; homeowner protection; financial sustainability; quality management; and dispute resolution. At the end, the research created a comparative framework of 101 codes that could be used to accurately measure the efficiency of a home warranty scheme.Originality/valueGathering all defining characteristics of new housing warranties into a unique comparative framework rectifies a gap in the literature. Such a flexible tool will aid future practitioners in the field to undertake comparative case study analysis through qualitative research methods.

Density of wood can be increased by filling its porous structure with polymers. Such densification processes aim to increase hardness of wood and are particularly interesting for flooring applications. This study aims to evaluate efficiency of different polymers for chemical densification based on the polymer properties. Yellow birch (Betula alleghaniensis Britt.) was chemically densified with seven monomer mixtures through acrylate monomer impregnation and electron beam in-situ polymerization. Chemical retention and polymer content of densified woods were recorded. Hardness of treated and untreated Yellow birch was measured and compared to hardness of Jatoba (Hymenaea courbaril L.). All densified woods showed higher or comparable hardness to Jatoba. Hardness of densified wood was analyzed in relation to initial density of wood and polymer content of the material using multivariable linear mixed models. Efficiency of polymers for chemical densification was evaluated through effect of polymer content on hardness with interaction coefficients. Polymer films corresponding to monomer impregnating mixtures were prepared through low energy electron beam and characterized by their glass transition temperature, micro hardness, indentation modulus and crosslinking density. Polymers showed statistically significantly different efficiencies and were separated in two main groups. Overall, polymer efficiency increased with increasing glass transition temperature of polyacrylates.

The building industry is under increasing pressure to develop and use sustainable approaches and materials. Replacing products from crude oil by co-products from bio-refinery processing can have both positive economic and environmental features. Crude glycerol, the main co-product from biodiesel production, is produced in large quantity, but have few applications. Crude glycerol has potential to substitute pure glycerol in some of its applications, as for the synthesis of polymers. Polymeric foams are materials used in building industry for insulation purpose but are mainly petroleum-based. Cellulose filaments are materials derived from biomass which could be used as fillers to modify the properties of a polymer. In this study, rigid composite polyester foams from crude glycerol with cellulose filaments has been developed to be used as thermal insulators for building industry. The samples have been characterized at different polymerization stages and at different conditioning cycles. FTIR analysis confirmed that the final polymerization created new ester bonds between glycerol and citric acid, which it was supported by the increase of Tg. The compressive strength values were higher after final polymerization but were affected negatively at high humidity. The use of crude glycerol resulted to a more homogenous pore structure and higher porosity than pure glycerol. Again, thermal conductivity and stability tests showed that crude glycerol foams were more reliable than pure glycerol ones for their thermal properties. Then, the crude glycerol foams absorbed more water and had lower density than pure glycerol specimens. At last, the adding of cellulose filaments enhanced the stability of volumetric swelling by comparison with glass fibers. Overall, from the specific conditions and methods used in this study the crude glycerol could replace pure glycerol for development of polymer, and the cellulose filaments were better fillers than common ones, such as glass fibers.

In this work, intumescent coatings were prepared for protection of wood from fire. The fire-retardant chemical ammonium polyphosphate (APP) is known to have poor resistance to water and high humidity as it is hygroscopic in nature. To improve the water resistance, durability and fire resistance of the intumescent coating, APP was modified using a hybrid organic-inorganic polysiloxane encapsulation shell prepared by the sol–gel method. The physical and chemical properties of the intumescent mix containing microencapsulated ammonium polyphosphate (EAPP) particles were characterized by X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), water absorption, dynamic vapor sorption (DVS) and thermogravimetric analysis (TGA). The EAPP mix showed 50% reduction in water absorption, 75% reduction in water vapor sorption and increased thermal stability when compared to the APP mix. The intumescent coatings were applied on wood samples, and their fire performance was evaluated using a cone calorimeter test. The intumescent coatings containing EAPP mix showed better fire retarding properties with longer time to ignition, lower heat release rate and shorter heat release peak when compared to the coating without EAPP mix. The prepared intumescent coating shows higher resistance to water and moisture, and it has great potential to be used in bio-based construction industry for enhancing the fire resistance of wood.

This study focuses on the development of advanced water-resistant bio-based membranes with enhanced vapour permeability for use within building envelopes. Building walls are vulnerable to moisture damage and mold growth due to water penetration, built-in moisture, and interstitial condensation. In this work, breathable composite membranes were prepared using micro-fibrillated cellulose fiber (CF) and polylactic acid (PLA). The chemical composition and physical structure of CF is responsible for its hydrophilic nature, which affects its compatibility with polymers and consequently its performance in the presence of excessive moisture conditions. To enhance the dispersibility of CF in the PLA polymer, the fibers were treated with an organic phosphoric acid ester-based surfactant. The hygroscopic properties of the PLA-CF composites were improved after surfactant treatment and the membranes were resistant to water yet permeable to vapor. Morphological examination of the surface showed better interfacial adhesion and enhanced dispersion of CF in the PLA matrix. Thermal analysis revealed that the surfactant treatment of CF enhanced the glass transition temperature and thermal stability of the composite samples. These bio-based membranes have immense potential as durable, eco-friendly, weather resistant barriers for the building industry as they can adapt to varying humidity conditions, thus allowing entrapped water vapor to pass through and escape the building, eventually prolonging the building life.

Air leaks have a considerable impact on the energy load and durability of buildings, particularly in cold climates. In wood construction using cross-laminated timber (CLT), air leaks are most likely to be concentrated at the joints between panels and other elements. This study used simulations of heat, air, and moisture transfers through a gap between two CLT panels causing air leakage in winter conditions under a cold climate. A real leakage occurrence was sized to validate the simulations. The aim of this work was to assess the impact on the energy loads and the durability of an air leak, as either infiltration or exfiltration, for different gap widths and relative humidity levels. The results showed that infiltrations had a greater impact on the energy load than exfiltrations but did not pose a threat to the durability, as opposed to exfiltrations. Gap sizes in CLT may vary, but the effect on the energy load was sensitive to the leakage path in the rest of the wall. As expected, a combination of winter exfiltration and a high level of interior relative humidity was particularly detrimental.

The main goal of this study was to review current studies on the state of the art of wood constructions with a particular focus on energy efficiency, which could serve as a valuable source of information for both industry and scholars. This review begins with an overview of the role of materials in wood buildings to improve energy performance, covering structural and insulation materials that have already been successfully used in the market for general applications over the years. Subsequently, studies of different wood building systems (i.e., wood-frame, post-and-beam, mass timber and hybrid constructions) and energy efficiency are discussed. This is followed by a brief introduction to strategies to increase the energy efficiency of constructions. Finally, remarks and future research opportunities for wood buildings are highlighted. Some general recommendations for developing more energy-efficient wood buildings are identified in the literature and discussed. There is a lack of emerging construction concepts for wood-frame and post-and-beam buildings and a lack of design codes and specifications for mass timber and hybrid buildings. From the perspective of the potential environmental benefits of these systems as a whole, and their effects on energy efficiency and embodied energy in constructions, there are barriers that need to be considered in the future.

Building elements are required to provide sufficient fire resistance based on requirements set forth in the National Building Code of Canada (NBCC). Annex B of the Canadian standard for wood engineering design (CSA O86-19) provides a design methodology to calculate the structural fire-resistance of large cross-section timber elements. However, it lacks at providing design provisions for connections. The objectives of this study are to understand the fire performance of modern mass timber fasteners such as self-tapping screws, namely to evaluate their thermo-mechanical behavior and to predict their structural fire-resistance for standard fire exposure up to two hours, as would be required for tall buildings in Canada. The results present the great fire performance of using self-tapping screws under a long time exposure on connections in mass timber construction. The smaller heated area of the exposed surface has limited thermal conduction along the fastener’s shanks and maintained their temperature profiles relatively low for two hours of exposure. Based on the heat-affected area, the study presents new design principles to determine the residual length of penetration that would provide adequate load-capacity of the fastener under fire conditions. It also allows determining safe fire-resistance values for unprotected fasteners in mass timber construction exposed up to two hours of standard fire exposure.

The objective of this study was to develop a new drywall wood-based particleboard as an alternative to gypsum board. Various development iterations have led to the use of wood particles, steatite powder and Portland cement. The resulting outcome shows that screw withdrawal resistance was improved by 37% and bending properties by 69% compared to gypsum board of a similar density (0.68&ndash, 0.70). The raw surface of the boards is of good quality and comparable to the paper-faced surface of gypsum board. Furthermore, the reaction to fire was evaluated through bench-scale test with a cone calorimeter. The investigated particleboard did not reveal visual signs of combustion after 20 min when exposed to a radiant heat of 50 kW/m2, while burning of the overlay paper of gypsum board occurred at about 57 s, suggesting that wood-cement-steatite powder particleboard could be classified as a quasi non-combustible material.

The goal of the present study was to develop a low-density thermal insulation board using wood fibers and a bio-based adhesive as a binder, which was prepared from a crude glycerol and citric acid mixture. The physical and mechanical properties of insulation boards manufactured using two ratios of crude glycerol and citric acid (1:0.66 and 1:1 mol/mol) and two adhesive contents (14% and 20%) were evaluated. The results show that the insulation boards with a range of density between 332 to 338 kg m−3 present thermal conductivity values between 0.064 W/m-K and 0.066 W/m-K. The effect of adhesive content was very significant for certain mechanical properties (tensile strength perpendicular to surface and compressive strength). The tensile strength (internal bond) increased between 20% and 36% with the increased adhesive content. In contrast, the compressive strength decreased between 7% and 15%. The thermo-mechanical properties obtained of insulation boards such as thermal conductivity, traverse strength, tensile strength parallel and perpendicular to surface, and compressive strength are in accordance with the requirements of the American Society for Testing and Materials C208-12 standard for different uses. The results confirm the potential of crude glycerol and citric acid mixture to be used as an adhesive in the wood fiber insulation boards’ manufacturing for sustainability purposes.

Fire safety regulations impose very strict requirements on building design, especially for buildings built with combustible materials. It is believed that it is possible to improve the management of these regulations with a better integration of fire protection aspects in the building information modeling (BIM) approach. A new BIM-based domain is emerging, the automated code checking, with its growing number of dedicated approaches. However, only very few of these works have been dedicated to managing the compliance to fire safety regulations in timber buildings. In this paper, the applicability to fire safety in the Canadian context is studied by constituting and executing a complete method from the regulations text through code-checking construction to result analysis. A design science approach is used to propose a code-checking method with a detailed analysis of the National Building Code of Canada (NBCC) in order to obtain the required information. The method starts by retrieving information from the regulation text, leading to a compliance check of an architectural building model. Then, the method is tested on a set of fire safety regulations and validated on a building model from a real project. The selected fire safety rules set a solid basis for further development of checking rules for the field of fire safety. This study shows that the main challenges for rule checking are the modeling standards and the elements’ required levels of detail. The implementation of the method was successful for geometrical as well as non-geometrical requirements, although further work is needed for more advanced geometrical studies, such as sprinkler or fire dampers positioning.

Most self-proclaimed sustainable neighborhoods cover various concepts pertaining to the economic, social, environmental, and institutional pillars of sustainability. Depending on the developers’ motivations, these concepts can be integrated unevenly. This study develops a framework to characterise the gap between what is advocated as necessary for sustainable neighborhoods and what is marketed as sustainable neighborhoods. A framework based on a sustainable neighborhood typology is developed using the Canadian province of Quebec as a case study. This is based on the main concepts underlying the four pillars of sustainability, but from a practical perspective. An analysis of sustainable initiatives ('n '= 29) shows a clear prioritisation of urban morphology on individual livability at the expense of participatory governance and sustainability awareness, especially for large projects promoted by private developers. A co-occurrence analysis suggests that smaller projects manage to integrate more sustainability aspects. The framework can be used to identify similarities and differences between development types for developing practical policy measures. This research highlights the importance involving public and private stakeholders at the early planning stage, in order to design more integrated projects. 'Policy relevance' A gap is revealed between what is defined as urban sustainability and what is actually delivered by developers. Citizen participation is generally beneficial, but often lacking. There is scope for policymakers to provide compelling encouragement to build citizen involvement into the planning processes, particularly for larger neighborhood developments. From the example of the province of Quebec, this can take several forms. In some cases, more incentives from the public sector to involve citizens at the early stage of planning is favorable. This can allow stakeholders to outline the development strategy in neighborhoods. In other cases, municipalities can involve residents through a charter or regular local meetings. This requires more systemic municipal approaches to urban sustainability. Evidence suggests that local relocation of food and/or energy production can lead to successful cases of citizen participation and social solidarity.

In the context of a low environmental impact energy mix, the embodied energy of building materials can account for up to 46% of a building's life cycle energy over a 50-year service life. Fifty percent of this energy corresponds to the combination of the structure and building envelope. While most studies have compared different residential building systems or wall assemblies, this study aims to quantify the contribution of initial embodied impacts to the environmental impacts of wall assemblies' life cycle for the exterior walls of an office building in Quebec City (Canada). Cradle-to-grave life cycle assessments were conducted on eight wall assemblies, three of which use light-frame construction, one lightweight steel framing, two cross-laminated timber and two glued-laminated timber in a post and beam approach. The life cycle impacts were evaluated using openLCA, the ecoinvent database and the TRACI method. Energy consumption during the use stage was simulated using EnergyPlus. The results indicate that initial embodied impacts can account for 40% to 66% of all environmental impacts throughout the wall assemblies' life cycle. These results suggest that, in this specific context, the initial embodied impacts can become the dominant source of environmental impacts in wall assemblies' life cycle. Many factors have been identified as affecting initial embodied impacts such as the choice, the quantity and the nature of materials. The results of this study will help decision makers to identify where efforts should be made to reduce a building's environmental impacts in similar context.

One of the major issues in the wood industry is the durability of clear coatings. The addition of organic ultraviolet absorbers (UVAs) improves coating resistance by the absorption and conversion of UV radiation into harmless heat. Organic UVAs are, however, easily degraded by free radicals produced by photodegradation inside the polymer matrix and are prone to migration in the coating. In this study, commercial UVAs and hindered amine light stabilizers (HALS) entrapped into poly(methyl methacrylate) (PMMA) microspheres and CaCO3 templates coated with UV-responsive polymers were added into clear acrylic water-based coating formulation. Artificial accelerated weathering experiments were performed on each formulation. Raman spectroscopy mapping was performed to visualize the concentration and distribution of UVAs and HALS. This study also presents a comparison of the mechanical properties of coatings obtained by dynamic mechanical analysis. Results showed that coating mechanical properties were improved when using encapsulated UVAs and HALS inside PMMA microspheres. The color change of the wood and coating system was minimized and the production of photo-oxidation compounds in the binder was also limited.

Intumescent fire retardant (IFR) coatings are nowadays considered as the most effective flame retardant (FR) treatment. Nevertheless, the principal compound in an IFR system, ammonium polyphosphate (APP), is highly sensitive to moisture and IFR coating effectiveness decreases quickly. The main objective of this study is to encapsulate APP in a hybrid silica-based membrane by sol-gel process using alkoxysilane tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) precursor. The morphology and structure of APP and microencapsulated ammonium polyphosphate (MAPP) were assessed by scanning electron microscopy and Fourier transforms infrared spectroscopy (FTIR). X-ray photoelectron spectroscopy (XPS) results revealed that APP was well encapsulated inside the polysiloxane shells. The thermal degradation of APP and MAPP was evaluated by thermogravimetric analysis. At 800 °C, the MAPP had higher char residue (70.49 wt%) than APP (3.06 wt%). The hydrophobicity of MAPP increased significantly with the water contact angles up to 98°, in comparison to 20° for APP.

Wood–plastic composites (WPC) are widely used for many purposes due to their interesting properties, but they have poor surface adhesion due to the chemical inertness of the matrix. Thus, in this work, the effect of plasma treatment on the WPC was investigated regarding its influence in the aluminum oxide (Al2O3) nanoparticles attachment to the surface. WPC were prepared in a polypropylene (PP) matrix, plasma-treated at 100 W for 600 s, and then covered with Al2O3 nanoparticles dispersion. The WPC/Al2O3 surfaces have been investigated by means of morphology, surface roughness, chemical structure, wettability, and nanohardness. Plasma treatment improved the attachment of Al2O3 onto WPC, which was confirmed by the higher presence of aluminum and oxygen-containing functional groups and the reduction of the intensity of peaks of methylene (CH2) and methyl (CH3) groups on the WPC surface. The higher surface reactivity of plasma-treated WPC resulted in a better distribution of the nanoparticles over the entire ...

This paper presents a case study of a recently built high-performance Canadian social housing building with the aim of comparing the expected and measured energy consumptions and to identify the parameters affecting the most the energy need. A monitoring system compiles at a 10-min frequency information related to the energy use and the thermal conditions observed in the building and its HVAC system. The building has the particularity of comprising two symmetric sections made of different timber structure systems. No significant differences of energy consumption were detected between the two parts of the buildings. However, a large variance was observed when comparing each dwelling individually regardless of their structures. The orientation of the dwelling also exhibited a minimal influence compared to these variations, suggesting that occupant behavior is the dominant factor explaining dwelling-to-dwelling variability and is thus critical for understanding energy use in residential buildings. Regression analysis showed that specific occupant actions, such as opening windows in winter or using electrical appliances, have a great impact on the energy balance of the apartments. In 2016, the performance gap between measured and expected total energy demand of the building was 74%. With the use of the large dataset coming from the building, it was possible to determine the causes behind this large gap for the reference building.

As part of a research program to expand the potential of wood products in exterior applications, lodgepole pine wood was impregnated with a solution of glycerol and citric acid to improve its dimensional stability and other relevant properties. Two catalysts were studied: one liquid (hydrochloric acid, HCl) and one solid (nanoclay, Cloisite 30B). After impregnation, the specimens were polymerized at two temperatures (160°C and 180°C). The nanoclay dispersion and reticulation analysis were performed by XRD and TEM methods. Other analysis methods such as SEM, DSC, TGA, FT-IR were used to characterize the treatment solutions, polymers and treated specimens. The dimensional stability, hardness, adhesion strength and roughness of the specimens were measured and analyzed. Cloisite 30B proved to be a good catalyst, as it contributed to improving the dimensional stability and hardness of the wood while outperforming the HCl catalyst in counteracting the adhesion strength loss attributed to the wood-polyme...

Increasing the use of wood in buildings is regarded by many as a key solution to tackle climate change. For this reason, a lot of research is carried out to develop new and innovative wood surface improvements and make wood more appealing through features such as increased durability, fire-retardancy, superhydrophobicity, and self-healing. However, in order to have a positive impact on the society, these surface improvements must be applied in real buildings. In this review, the last five years of research in the domain of wood surface improvements and modifications is first presented by sorting the latest innovations into different trends. Afterward, these trends are correlated to specifications representing different normative, ecologic and economic factors which must be considered when expecting to introduce a wood treatment to the market. With this review, the authors hope to help researchers to take into consideration the different factors influencing whether new innovations can leave the research laboratory or not, and thereby facilitate the introduction of new wood surface treatments in the society.

Cross-Laminated Timber (CLT) structures have been emerging worldwide for residential floors in multi-storey buildings thanks to their lightness, fast construction and low ecological footprint. This work aims at fostering this application, which is often limited by vibrational and deflection limits, by investigating composite slab floors made of CLT and High-Performance Concrete (HPC) slab as well as CLT and Ultra High-Performance Fiber Reinforced Concrete (UHPFRC). Firstly, the composite floors CLT-HPC and CLT-UHPFRC with a span of 8 m were designed by considering a multicriteria analysis. To assure a certain structural ductility, previously developed ductile notch connectors were employed. As an economic choice, no shear reinforcement in the concrete slab was employed. Then, full-scale composite beams were fabricated in order to verify the predicted flexural behaviour and natural frequency. A numerical analysis was carried out to verify the connectors could effectively yield before the timber collapse. The comparison between the numerical simulation and the slip measurements confirmed that about 50% of the notch connections fully yielded and underwent inelastic deformation which favors the structural ductility. In the case of the CLT-HPC floor, a reduction of the notch contact surface due to the use of plastic sheet waterproofing as well as shear cracks developing in the concrete close to the notch corner both reduced the expected structural stiffness. Finally, the CLT - UHPFRC floor is endowed with outstanding values of slenderness ratio (∼35) and lightness (∼2 kPa), while eliminating the use of shear reinforcement and sheet waterproofing.

In the province of Quebec, Canada, Small and Medium Enterprises (SMEs) in manufactured timber construction seeking to expand their market must necessarily go beyond the local trade. By exporting their products and manufactured building sections to another country, Quebec manufacturers must deal with significant regulations and certification constraints. The aim of this study is therefore to propose a method to qualify the impacts of these constraints on the export of manufactured buildings to New England in order to create a decision support tool. Since construction regulations vary depending on the location of the project, those relating to Massachusetts were analyzed, as this is currently the main destination for manufactured building sections. Considering the federal and local regulations in effect, a content analysis of the Quality Assurance Manual (QAM) set up by an industry partner and a third-party certifier enabling exports to Massachusetts was performed. In particular, the six-step method proposed by L’Écuyer was exploited for extracting and examining relevant information from regulatory texts. Through this analysis, the importance of quality control was confirmed as a keystone for certification. It also led to a better understanding of the relationships between quality control, the construction process and installation, the design and engineering choices, and the strategy to choose the project.

Over the last few decades, wood modification has been performed to improve wood product technical performance. Using renewable based chemicals for wood modification is an innovative alternative to the non-renewable petrochemicals commonly used. However, it should be kept in mind that having the raw material from renewable sources does not guarantee zero environmental impacts. In this study, the treatment considered uses citric acid and glycerol mixture; two chemical products derived from renewable sources. In the residential building context of Quebec-Canada, the cradle-to-grave life cycle assessment for untreated and treated lodgepole pine wood siding was performed and compared. The results obtained show that the treated wood siding has higher environmental impacts than the untreated wood siding, in spite of its longer service life. This is partially caused by the high contribution of citric acid production used for treatment. The current service life expectancy of treated wood siding was estimated to be 2.8 times longer than the one of untreated wood siding based on standardized durability test and classification (AWPA E 10–12 and ASTM D 2017-05). Sensitivity analysis showed that life cycle impacts of treated wood siding become lower than those from untreated wood siding when service life expectancy reaches 5-times that of untreated wood siding. Life cycle assessment could be used for guidance in developing better treatments to improve their environmental impacts.

Summary Various green building rating systems (GBRSs) have been proposed to reduce the environmental impact of buildings. However, these GBRSs, such as Leadership in Energy and Environmental Design (LEED) v4, are primarily oriented toward a building's use stage energy consumption. Their application in contexts involving a high share of renewable energy, and hence a low-impact electricity mix, can result in undesirable side effects. This paper aims to investigate such effects, based on an existing office building in Quebec (Canada), where more than 95% of the electricity consumption mix is renewable. This paper compares the material impacts from a low-energy context building to material considerations in LEED v4. In addition to their contributions to the building impacts, material impacts are also defined by their potential to change impacts with different material configurations. Life cycle assessment (LCA) impacts were evaluated using Simapro 8.2, the ecoinvent 3.1 database, and the IMPACT 2002+ method. The building LCA results indicated higher environmental impact contributions from materials (>50%) compared to those from energy consumption. This is in contrast with the LEED v4 rating system, as it did not seem to be as effective in capturing such effects. The conclusions drawn from this work will help stakeholders from the buildings sector to have a better understanding of building environmental profiles, and the limitations of LEED v4 in contexts involving a low-impact energy mix. In addition, this critical assessment can be used to further improve the LEED certification system.

The durability of clear coatings is an important problem in the coatings industry. This problem can be partly solved with the addition of UV absorbers (UVAs) in the coating formulation. UVAs can absorb part of the UV radiation and convert it into harmless heat. Organic UVAs are prone to photodegradation and can migrate in the binder of a coating formulation. In this study, commercial UVAs have been encapsulated in poly(methyl methacrylate) microspheres using the internal phase separation method. Microspheres have been incorporated into a clear acrylic binder. The acrylic was then applied on wood panels and was placed into an artificial UV chamber. Efficiency of coatings after aging as well as chemical and physical properties were monitored using a colorimeter, FTIR spectroscopy and transmission electron microscopy. This study presents a comparison between the efficiency of free and encapsulated Tinuvin 1130 and 292 commercial absorbers. Results have shown that the coating efficiency is slightly improved when using the encapsulated products.

Several cloud retrieval algorithms based on satellite observations in the infrared have been developed in the last decades. However, these observations only cover the midinfrared (MIR, λ < 15 μm) part of the spectrum, and none are available in the far-infrared (FIR, λ≥ 15 μm). Using the optimal estimation method, we show that adding a few FIR channels to existing spaceborne radiometers would significantly improve their ability to retrieve ice cloud radiative properties. For clouds encountered in the polar regions and the upper troposphere, where the atmosphere is sufficiently transparent in the FIR, using FIR channels would reduce by more than 50% the uncertainties on retrieved values of optical thickness, effective particle diameter, and cloud top altitude. Notably, this would extend the range of applicability of current retrieval methods to the polar regions and to clouds with large optical thickness, where MIR algorithms perform poorly. The high performance of solar reflection-based algorithms would thus be reached in nighttime conditions. Since the sensitivity of ice cloud thermal emission to effective particle diameter is approximately 5 times larger in the FIR than in the MIR, using FIR observations is a promising venue for studying ice cloud microphysics and precipitation processes. This is highly relevant for cirrus clouds and convective towers. This is also essential to study precipitation in the driest regions of the atmosphere, where strong feedbacks are at play between clouds and water vapor. The deployment in the near future of a FIR spaceborne radiometer is technologically feasible and should be strongly supported.

The development of wood treatments is of increasing industrial importance. A novel technique for improving the properties of lodgepole pine and white pine through modification of the microstructure is described. The present investigation is devoted to the synthesis and determination of in situ parameters of citric acid and glycerol based polymers for wood impregnation. This solvent free approach is environmentally friendly and achieved through an esterification condensation reaction under acidic conditions. Crude glycerol and citric acid reactants were cross-linked via a curing process at 160 °C creating a polymer with only water as the byproduct. The ester bonds and crosslinking levels were controlled using different catalysts and citric acid contents and related to the reaction time and temperature. The nature of bonding within the polymers and at the wood cell walls was determined by FT-IR analysis. The thermal properties such as glass transition temperature (Tg) were studied using TGA/DSC and the effect of citric acid content and catalyst type determined. Dimensional stability of impregnated wood samples improved above 50% for each sample with HCl and p-TSA catalysts compared to control samples. FTIR spectra were studied to show the presence of the ester linkages of the polymer in situ at the wood cell walls. Bonding between the polymer and wood macromolecules were observed by scanning electron microscopy and interpreted as evidence of chemical bonds at the wood cells. When prepared using a catalyst, the polymer was intimately incorporated into wood structure significantly improving the substrate dimensional stability. Enhanced stability makes this approach of particular interest for exterior wood products especially as a green renewable option for the wood industry.

Wood is a material often used by architects to enhance the overall ambience of a space, but few researches have been reported to discuss its actual impact on visual impression and luminous effects. This research studies the influence of wood materiality in relation to creating specific lighting ambiances in architecture. In particular, it focuses on the impact of decorative wood indoor panels on the creation of daylighting diversity in interior space and the potential to improve daylighting quality and energy efficiency. The research uses scaled models for their accuracy in rendering complex daylighting ambiances. The photo-luminance meter enables the comparison between different settings of interior spaces created by a selection of wood type materiality: ratio (percentage), colour (Oak, Cape Cod Grey and Dark Walnut coatings) and gloss concerning illuminance patterns obtained from Ecotect software. The CIE L*a*b* colour space is used to classify luminous ambiances. Results indicate that bright colour Oak favours a deeper daylighting penetration and increases the colour temperature of the space by about 300% when applied on the floor. Cape Cod Grey coating provided a neutral colour balance even under sunlighting. High gloss Dark Walnut located on the ceiling produces the highest luminance values, enlarging the window-lighting pattern. The research underlines the role of wood materiality in achieving luminous diversity and creating visually comfortable interior ambiances.

Steel and concrete are traditionally used as structural materials for non-residential and multi-housing buildings. However, wood can meet the same structural property requirements, and a variety of multi-story buildings have recently been built all over the world using this key material. In this study, the main motivations and barriers to wood adoption for structural uses in non-residential buildings are highlighted, based on an analysis of grey literature concerning some well-known buildings and on scientific literature. The motivations found were linked to sustainability, lack of expertise, costs, rapidity of erection, and aesthetic of wooden structures. In contrast, the barriers preventing its use encompass building code implementation, technology transfer, costs, material durability and other technical aspects, culture of the industry, and material availability. Furthermore, an analysis of non-residential timber building meeting minutes for nine projects is also presented to support the identification of problems and concerns related to site assembly issues, the conception of the building, the scheduling, and stakeholders’ relationships. With a better understanding of the expectations and challenges concerning wood usage in non-residential construction projects, companies will be able to adapt their business models and use the resource even more in the future to develop innovative structures.

Currently, green roof fire risks are not clearly defined. This is because the problem is still not well understood, which raises concerns. The possibility of plants catching fire, especially during drought periods, is one of the reasons for necessary protection measures. The potential fire hazard for roof decks covered with vegetation has not yet been fully explored. The present study analyzes the performance of green roofs in extreme heat conditions by simulating a heat transfer process through the assembly. The main objective of this study was to determine the conditions and time required for the roof deck to reach a critical temperature. The effects of growing medium layer thickness (between 3 and 10 cm), porosity (0.5 to 0.7), and heating intensity (50, 100, 150, and 200 kW/m²) were examined. It was found that a green roof can protect a wooden roof deck from igniting with only 3 cm of soil coverage when exposed to severe heat fluxes for at least 25 minutes. The dependency of failure time on substrate thickness decreases with increasing heating load. It was also found that substrate porosity has a low impact on time to failure, and only at high heating loads.

Interest in intrinsically low-energy construction materials is becoming mainstream, and bio-based materials form a key part of that group of materials. The goal of this study was to analyse the environmental impact of applying a sol-gel coating on hemp shiv, in order to improve the durability of this innovative bio-based material, using a regionalised LCA model, taking into account regional specific peculiarities. This study analysed the environmental performance of using bio-based materials in the building envelope compared with traditional synthetic construction materials, and compared the impact of a regionalised approach with a global approach. The carbon footprint of treated hemp shiv in a wall with a U-value of 0.15 W/m2.K was compared to untreated hempcrete and a reference cavity wall with the same U-value. Considering the environmental damage caused by the production of hemp shiv, nitrogen fertiliser was the hotspot. The LCA results showed that, using innovative bio-based materials in construction, treated hemp shiv with sol-gel can decrease the carbon footprint of a building envelope through carbon sequestration. Using the more accurate site-specific information in life cycle inventory and impact assessment methods will result in more consistent and site-appropriate environmental results for decision-making.

The aim of this study was to consider the use of biomass wood ash as a partial replacement for cement material in wood-cement particleboards. Wood-cement-ash particleboards (WCAP) were made with 10%, 20%, 30%, 40%, and 50% of wood ash as a partial replacement for cement with wood particles and tested for bending strength, stiffness, water absorption, and thermal properties. Test results indicate that water demand increases as the ash content increases, and the mechanical properties decrease slightly with an increase of the ash content until 30% of replacement. On the other hand, the heat capacity increases with the wood ash content. The WCAP can contribute to reducing the heat loss rate of building walls given their relatively low thermal conductivity compared to gypsum boards. The replacement of cement to the extent of approximately 30% by weight was found to give the optimum results.

The benefits of aluminum lamination in improving the physical and mechanical properties of wood-based composites is now well documented. This paper shows the contribution of life cycle assessment (LCA) as a tool to assess and compare the environmental footprint in the development of laminated panels. SimaPro 9.0 software, using Ecoinvent database was used to analyze the environmental impacts associated with the manufacturing of wood aluminum-laminated (WAL) panels and aluminum honeycomb panel (AHP). The impact 2002+ method was used to estimate environmental impacts. The LCA results show that the WAL panels manufacturing had a lower environmental impact than AHP manufacturing. In term of product, wood-based composites were the best choice as a core in laminated panel manufacturing. Wood-based composite manufacturing showed environmental advantages in all damage categories except in ecosystem quality. Aluminum alloy sheets manufacturing played an important role in the generation of environmental impacts for laminated panel development.

Research Highlights: This is the first study that analyzes the environmental performance of wood-based phase change material (PCM) panels. Background and Objectives: Life cycle assessment (LCA) is a powerful environmental management tool. However, a full LCA, especially during the early design phase of a product, is far too time and data intensive for industrial companies to conduct during their production and consumption processes. Therefore, there is an increasing demand for simpler methods to demonstrate a company&rsquo, s resource efficiency potential without being data or time intensive. The goal of this study is to investigate the suitability of streamlined LCA (SLCA) tools and methods used in the building material industry, and to assess their robustness in the case study of a wood-based PCM panel. Materials and Methods: The Bilan Produit tool was selected as the SLCA tool and a matrix LCA was selected as the most commonly used SLCA method. A specific case study of a wood-based PCM panel was selected with a focus on its application in building construction in the province of Qu&eacute, bec. Results: As a semi-quantitative LCA method, the matrix LCA provided a quick screening of the product life cycle and its hotspot stages, i.e., life cycle stages with high impact. However, the results of the full LCA and SLCA tools were quantitative and based on scientific databases. The use of the PCM panel and heating energy had the highest environmental impacts as compared to other inputs. The results of the full LCA and SLCA also identified energy consumption as a hotspot. Insufficient material or processes in the SLCA databases was one of the reasons for the difference between the results of the SLCA and full LCA. Conclusions: The examined SLCA methods provided proper explanations for the bio-based material in construction, but several limitations still exist, and the methods should be improved to make them more robust when implemented in such a specific sector.

Wood is a porous material that can be impregnated and have enhanced properties. Two species of hardwood, red oak (Quercus rubra L.) and sugar maple (Acer saccharum Marsh.), were impregnated in a reactor with a microencapsulated phase change material. The objective was to enhance the thermal mass of wood boards used as surface layers for engineered wood flooring manufacturing. Preliminary experiments were conducted on small samples in order to define suitable impregnation parameters, based on the Bethell cycle. Thin wood boards were impregnated with a microencapsulated phase change material dispersed into distilled water. Several cycles of pressure were applied. Heating storage of the impregnated wood boards was determined using a dynamic heat flow meter apparatus method. A latent heat storage of 7.6 J/g over 3 &deg, C was measured for impregnated red oak samples. This corresponds to a heat storage enhancement of 77.0%. Sugar maple was found to be harder to impregnate and thus his thermal enhancement was lower. Impregnated samples were observed by reflective optical microscopy. Microcapsules were found mainly in the large vessels of red oak, forming aggregates. Pull-off tests were conducted on varnished samples to assess the influence of an impregnation on varnish adhesion and no significant influence was revealed. Engineered wood flooring manufactured with impregnated boards such as characterized in this study could store solar energy and thus improve buildings energy efficiency. Although wood is a material with a low-conductivity, the thermal exchange between the PCM and the building air could be good enough as the microcapsules are positioned in the surface layer. Furthermore, flooring is an area with frequent sunrays exposure. Such high thermal mass EWF could lead to energy savings and to an enhancement of occupant&rsquo, s thermal comfort. This study aimed to characterize the potential of impregnation with MPCM of two wood species in order to make high thermal mass EWF.

Timber structures in construction have become more popular in recent years. Nevertheless, besides the complexity of designing, contracting and building these structures, a barrier to their market growth is the complexity of their supply chain relationships encompassing architects, engineers, builders and suppliers. The objective of this study is therefore to identify and characterize the supply chain relationships shared by these stakeholders within a massive timber construction project. Twenty-seven semi-structured interviews with architects, structural engineers, builders and timber element suppliers from nine countries, participant observations and secondary data were used to study the various relationship levels involved in timber construction projects. Triangulation and qualitative data analysis were also conducted. Three levels of relationships were then identified: &ldquo, Contractual,&rdquo, &ldquo, Massive timber construction project&rdquo, and &ldquo, Massive timber construction industry development.&rdquo, Results showed that timber structures involve value-added stakeholder relationships rather than linear relationships. These relationships appeared closer and more frequent and involved knowledge and information sharing. Furthermore, prefabricated systems allow for smoother relationships by limiting the number of stakeholders while promoting innovative thinking.

The relatively low thermal mass of timber frame buildings is a limiting factor for their energy efficiency and for the thermal comfort. The aim of this study is to assess the performance of wood-based wallboards integrated with PCM (Phase Change Materials) in a cold climate (Qu&eacute, bec, Canada), from the heating season to the summer. Two timber-frame test huts, of 2 &times, 2.5 &times, 3 m, were built following the National Building Code of Canada and placed in the LAVAL University Campus. The first hut was equipped with wood-based panels integrated with the commercial bio-based PCM Puretemp&reg, 23 with a 23 &deg, C melting point. The second hut was equipped with standard interior wood panels. Large double glaze windows were installed facing south. Dry indoor air temperatures were recorded for both huts and for the heating season, heating consumptions were monitored. The behaviour of the two huts was compared and PCM panels efficiency was evaluated over several seasons. A reduction of heating consumption was observed for cold months. For the heating season, panels were found to be more efficient as the months were getting milder. By gathering solar energy during the day, they allowed to reduce the test-hut heating consumption, by a maximum of 41% in May. In summer, the PCM panels had a positive impact in order to reduce the hut overheating. However their efficiency was found limited by a poor ability of discharge during the night. The solidification of the PCM was often impossible to achieve due to unsuitable night conditions. The results presented in this study will improve the knowledge concerning wood/PCM composites performance and concerning PCMs issues in cold climates. This study exposes the potential of wood-based panels integrated with PCM to achieve winter energy savings and enhance the summer thermal comfort of a timber-frame building, for a cold Canadian climate.

The use of timber as structural building material is growing and a greater number of firms are looking to enter this raising market. Erecting a complex timber building usually involves combining the work of architects, structural engineers, builders, suppliers and/or supplier–builders, all of them having their own business models. The purpose of this research was to uncover the specific nature of business models in the timber structure building industry. First, a thorough mapping of these business models was undertaken. Second, underlying patterns were uncovered within these models. A triangulation method of secondary data, semi-structured interviews and participant observation was used to allow for an in-depth study of 23 stakeholder business models. The analysis shows that knowledge sharing appears as crucial and may be achieved through sustained collaboration. As a result, collaborative contract procurement modes seem to be the most appropriate for timber construction. Tight relationships with suppliers and supplier–builders also appear as prerequisites. Furthermore, stakeholder partnerships with universities appear common in the field, while prefabrication is increasing in popularity. These findings can be useful to grasp the prevailing business models in this industry given the sustained growth of the timber structure building market.

Because of their availability, mechanical properties and distinctive appearance, there is a growing interest for the use of hardwood species in structural products such as glued-laminated timber. Previous work on bonding and structural grading of northern hardwoods has shown that white ash (Fraxinus americana L.), yellow birch (Betula alleghaniensis Britt.) and white oak (Quercus alba L.) are promising species for the manufacture of Canadian hardwood glulam. The objective of this study was to investigate the impact of the finger joint profile on the tensile strength of jointed hardwood lamellae. Tensile tests conducted on finger-jointed lamellae confirmed the possibility to achieve characteristic tensile strengths up to 36.4 MPa for white ash, 33.6 MPa for yellow birch and 35.8 MPa for white oak. One white ash and two yellow birch full-size beams were also manufactured using the most efficient finger joint profile and submitted to bending tests, achieving strengths of 47.0 and 41.6 MPa, respectively. The investigated species gave promising results suggesting they could be suitable for the manufacture of glued-laminated timber, although further research is required on hardwood finger-jointing to optimize the machining and gluing parameters and increase the joint efficiency.

In this study, fluorocarbon thin films were deposited on the surface of white spruce and Brazilian cedar woods via atmospheric pressure dielectric barrier discharge in the afterglow mode with octafluoropropane gas. A pre-treatment with oxygen plasma was introduced before the thin film deposition to determine if this plasma condition could increase the wood nano/micro roughness, helping to improve the hydrophobicity of the surface. The optimal conditions of water repellency for both woods were examined in terms of their resistance to aging in controlled conditions. The water contact angle measurements showed a hydrophobic surface with a stable angle for both woods. X-ray photoelectron spectroscopy reveals the presence of CF, CF2 and CF3 functional groups after the Ar/C3F8 plasma, especially for longer treatments. The open-air system of the plasma reactor leads to the simultaneous fluorination and incorporation of oxygen-containing groups. The pre-treatment of oxygen plasma increases the wood roughness; however, the chemical attachment of oxygen molecules is more significant, negatively affecting the degree of repellency of the plasma-coated woods. On the other hand, the fluorocarbon deposition increases the wood roughness and creates a hydrophobic surface simultaneously. Even with partial defluorination after aging, both plasma-coated woods retain a similar degree of water repellency, which partially avoid chemical reorganization of their surface due to environmental exposure.

This work investigates the adhesion properties of medium density fiberboard (MDF) panel surfaces treated by an argon plasma at two power levels (50 and 150 W) and four glow discharge times (10, 40, 60 and 120 s) and then coated with an acrylic emulsion. Wettability parameters and film formation kinetics were investigated by water apparent contact angle and diffusing wave spectroscopy, respectively. Pull-off strength was used to determine coating/wood adhesion. The aging effect of 300-days in storage at ambient conditions was examined by apparent contact angle measurements. The wettability of the MDF surface was enhanced significantly - especially at the 150 W power level – that improves coating/wood adhesion. A film formation process occurred in shorter time for plasma treated samples due to the faster motion of particles. MDF panels partially recovered their natural hydrophobicity in the first ten days of storage. Nevertheless, higher levels of power and time of glow discharge were able to slow down the aging effects.

Glued-in rods have successfully been used for connections or reinforcement of timber structures due to their high strength and stiffness. However, their performance is potentially sensitive to temperature. This paper deals with an experimental investigation of the connections and adhesives in elevated temperatures. First, dynamic mechanical analysis (DMA) tests were performed to characterize an epoxy (EPX) and a polyurethane (PUR) adhesive. The evolution of the stiffness and the glass transition temperature, Tg, were measured in the range of 30 °C to 120 °C. Then, a total of 66 specimens with glued-in rods and the same adhesives were tested under a static tensile load at 20 °C, 40 °C, 50 °C, 60 °C, and 70 °C. In both types of tests, the EPX outperformed PUR due to its higher stiffness at temperatures of up to 40 °C; however, it showed a more rapid degradation of the stiffness and strength than the PUR at higher temperatures. No direct correlation was established between the Tg and the performance of the connections. The test results suggest that timber structures with glued-in rods may be vulnerable in service at temperatures above 40 °C.

As environmental awareness grows, societal demand for more environmentally friendly products increases. Demand for environmental responsibility also reached the building material and construction sector. Green building has become more widespread over the past decade and can be considered a challenge for specifiers and building products manufacturers. Ecodesign, an application of the sustainable development concept, is one of the available tools to address this challenge. This article aims at proposing an ecodesign pathway for appearance wood products in the nonresidential building sector. Through extrapolating results from a previous interior wood door case study, it has been possible to obtain environmental profiles for the main segments of the appearance wood products family for nonresidential buildings. These profiles have allowed devising ecodesign solutions. Results show that for this whole family of products, raw materials are what cause the most environmental impacts, followed by shipping ...

The photodegradation of white spruce by artificial ageing was studied by several techniques: colourimetry, FTIR-ATR and FT-Raman spectroscopy. Samples were exposed at a xenon lamp for 2000h. Two distinct colour changes were found by colourimetric analysis, yellowing and silvering. These colour modifications indicate the formation of chromophoric structures which supports previous FTIR-ATR experiments. The degradation of lignin to generate the first chromophoric group for yellowing and then the appearance of surface layer cellulose. New carbonyl compounds conjugated with double bond at 1615cm(-1) are probably the second chromophoric group. The crystallinity index was also calculated and showed an increase of cellulose crystallinity by prior degradation of amorphous cellulose. The FT-Raman analysis confirms the wood sensitivity to photodegradation but the most remarkable results is the increase of fluorescence as a function of time. In softwood lignin, the compound able to produce fluorescence is a free rotating 5-5' linkage of one biphenyl structure. At native state these linkages are not free rotating, this phenomenon means the release of 5-5' linkage of lignin structure by cleavage of both α carbon linkages (Norrish type I reaction). These data confirm also the photosensitivity of α and β carbon in lignin and the resistance of 5-5' linkages.

Integrating environmental aspects into industrial practices has become a necessity. In fact, climate change and resource depletion have been established scientifically and can no more be neglected. Life Cycle Assessment is acknowledged to be an efficient tool to establish a product environmental profile and can be useful to businesses wishing to analyze their environmental record. Decreasing a building environmental footprint implies, among other considerations, a proper choice of building materials, both structural and architectural. A good avenue would be to select low environmental impact materials from cradle-to-grave . Architectural wooden doors are often specified in non-residential buildings in North America. However, only one Life Cycle Assessment has been carried out on wooden doors. This study explores the cradle-to-grave environmental profile of an interior wood door in a North American context. According to the results, the main contributor to the product impacts is the production of raw materials, especially the particleboard component, and their transportation to the manufacturing plant. The urea formaldehyde production is the main reason for particleboard impacts among the three damage categories, human health, climate change and resources, of IMPACT 2002+ . The other life cycle stages that have a noticeable influence on the door environmental impacts are shipping and end-of-life. Transportation as a whole affected the system total environmental score. The current results could serve as a basis for ecodesign implementation.

Assessing the fire risk of vegetated roofs includes the determination of their possible contribution to fire. Green roof components such as plants and growing media are organic materials and present a fuel that can catch and support the spread of fire. The flammability characteristics of these components were analyzed and compared to a typical roof covering. Growing media with 15% of organic matter were tested using cone calorimeter apparatus. The fuel load and heat release rate of the growing media were measured in both moist (30%) and dry conditions. It was observed that growing media in a moist condition do not present a fire risk, reaching a maximum heat release rate of 33 kW/m2. For dry substrates, a peak heat release rate of 95 kW/m2 was recorded in the first minute, which then rapidly decreased to 29 kW/m2 in the second minute. Compared to a typical bitumen roof membrane, the green roof showed a better fire performance. The literature data report more severe results for plant behavior, reaching peak heat release rates (HRRs) of 397 kW/m2 for dried and 176 kW/m2 for a green material. However, a rapid decrease in HRR to much lower values occurs in less than 2 min. The results also show that extensive and intensive types of green roofs present 22% and 95% of the additional fire load density when installed on a modified bitumen membrane, 19.7 and 85.8 MJ/m2, respectively.

Different kinds of ductile connectors have been lately developed for enhancing the structural ductility of Timber-Concrete Composite (TCC) structures. In particular, ductile notch connections can be designed by favoring the local compression failure of wood fibers. This work aims at further developing economic and ductile notch connector by considering different floor systems made of Glulam Laminated Timber (GLT) beam or Cross Laminated Timber (GLT or CLT) slab connected with a High Performance Concrete (HPC) slab or a Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) slab. Firstly, the geometry of the notch connector was suitably designed for favoring a ductile hierarchy of collapse modes. Then, a wide campaign of push-out tests was carried out to characterize the shear behaviour of 14 connection configurations by varying the notch geometry, the concrete type and the possible presence of acoustic insulation. Finally, based on the experimentally identified connection shear law, an example of design is presented for a TCC slab of 9 m span. The insulation layer was found to reduce the connection stiffness, but to increases the structural stiffness thanks to the enhanced lever arm of the composite action. For plastically designed TCC structures, the connection ductility allows increasing the structural ductility for both GLT-(U)HPC and for CLT-(U)UPC floor systems.

The energy efficiency of buildings is well documented. However, to improve standards of energy efficiency, the embodied energy of materials included in the envelope is also increasing. Natural fibers like wood and hemp are used to make low environmental impact insulation products. Technical characterizations of five bio-based materials are described and compared to a common, traditional, synthetic-based insulation material, i.e., expanded polystyrene. The study tests the thermal conductivity and the vapor transmission performance, as well as the combustibility of the material. Achieving densities below 60 kg/m3, wood and hemp batt insulation products show thermal conductivity in the same range as expanded polystyrene (0.036 kW/mK). The vapor permeability depends on the geometry of the internal structure of the material. With long fibers are intertwined with interstices, vapor can diffuse and flow through the natural insulation up to three times more than with cellular synthetic (polymer) -based insulation. Having a short ignition times, natural insulation materials are highly combustible. On the other hand, they release a significantly lower amount of smoke and heat during combustion, making them safer than the expanded polystyrene. The behavior of a bio-based building envelopes needs to be assessed to understand the hygrothermal characteristics of these nontraditional materials which are currently being used in building systems.