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Solutions for mid-rise wood construction: full-scale standard fire test for exterior wall assembly using a simulated cross-laminated timber wall assembly with interior fire-retardant-treated plywood sheathing: Test EXTW-4: report to Research Consortium fo

Solutions for mid-rise wood construction: full-scale standard fire test for exterior wall assembly using a simulated cross-laminated timber wall assembly with interior fire-retardant-treated plywood sheathing: Test EXTW-4: report to Research Consortium for Wood and Wood-Hybrid Mid-Rise Buildings

One of the tasks in the project, Wood and Wood-Hybrid Midrise Buildings, was to develop further information and data for use in developing generic exterior wall systems for use in mid-rise buildings using either lightweight wood frame or cross-laminated timber as the structural elements. This report describes a standard full-scale exterior wall fire test conducted on October 30, 2012 on a simulated cross-laminated timber (CLT) wall assembly with an attached insulated lightweight wood frame assembly protected using interior fire-retardant-treated (FRT) plywood sheathing. The test was conducted in accordance with CAN/ULC-S134 [3].
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Fire performance of mass-timber encapsulation methods and the effect of encapsulation on char rate of cross-laminated timber

Fire performance of mass-timber encapsulation methods and the effect of encapsulation on char rate of cross-laminated timber

KEYWORDS: Wood, Cross-Laminated Timber, Fire Resistance, Encapsulation, Char Rate 1 INTRODUCTION 12345 A recent shift toward increasingly tall wood buildings due to new technologies, products and systems has led to the construction of more than 17 tall mass timber buildings (seven stories or taller) around the world. Next generation mass timber products utilized in mid- and high-rise buildings includes cross-laminated timber (CLT). CLT is an engineered, wood composite product consisting of multiple layers, or plies, of dimensional lumber or structural composite lumber (SCL) that are glued perpendicular to each other to achieve strength in multiple directions [1]. There are several reasons to use mass-timber—and specifically CLT—as a building material, including: sustainability, offsite prefabrication, reduced construction time and costs, and increased architectural options [2].
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Sound insulation performance of cross laminated timber building systems

Sound insulation performance of cross laminated timber building systems

5. Summary and Conclusions In this paper the prediction methods of ISO 15712 are outlined and applied for Cross Laminated Timber (CLT) construction in North America. Since the ISO 151712 is using ISO terms and in North America ASTM-Standards are used for testing of building elements where possible these quantities were used as input data. Further, methods were outlined that were applied to transfer the measured input data of the element performance (Sound Transmission Loss (TL) and Normalized Impact Sound Pressure Level (NISPL)) from the lab situation to the field situation that is predicted. The non-resonant transmission component of the TL was removed utilizing the radiation efficiencies for airborne and structure-borne excitation. It was shown that this correction is only significant for elements with a coincidence frequency in the mid or high frequency range, like 3-ply CLT panels with a coincidence frequency of 800 Hz. For the 5-ply CLT panels with a coincidence frequency of about 200 Hz the correction for the non-resonant transmission component did not change the results significantly. Further, CLT elements have a comparable high internal loss factor (greater than 0.03) and the ISO 15712 standards suggest that the loss factor correction that requires a rather tedious prediction of the total loss factors for the field situation is not necessary and only the geometry of the lab has to be adjusted to the field situation.
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Solutions for mid-rise wood construction: full-scale standard fire test for exterior wall assembly using a simulated cross-laminated timber wall assembly with gypsum sheathing: Test EXTW-2: report to Research Consortium for Wood and Wood-Hybrid Mid-Rise B

Solutions for mid-rise wood construction: full-scale standard fire test for exterior wall assembly using a simulated cross-laminated timber wall assembly with gypsum sheathing: Test EXTW-2: report to Research Consortium for Wood and Wood-Hybrid Mid-Rise Buildings

One of the tasks in the project, Wood and Wood-Hybrid Midrise Buildings, was to develop further information and data for use in developing generic exterior wall systems for use in mid-rise buildings using either lightweight wood frame or cross-laminated timber as the structural elements. This report describes a standard full-scale exterior wall fire test conducted on May 22, 2012 on a simulated cross-laminated timber (CLT) wall assembly with an attached insulated lightweight wood frame assembly protected using gypsum sheathing. The test was conducted in accordance with CAN/ULC-S134 [3].
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Full scale exterior wall test on Nordic cross-laminated timber system

Full scale exterior wall test on Nordic cross-laminated timber system

The wall was assembled as follows for the test: 1. 15.9 mm thick Type X gypsum board on the test facility 2. 3 Ply, 105 mm thick Cross Laminated Timber wall panels manufactured by Nordic, including Glulam header (CLT wall panels can be thicker than the panels used. However, a thickness of 105 mm was considered adequate for this

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Fire endurance of cross-laminated timber floor and wall assemblies for tall wood buildings

Fire endurance of cross-laminated timber floor and wall assemblies for tall wood buildings

Executive Summary Standard fire endurance tests were performed on a full-scale floor assembly and a full-scale wall assembly constructed with cross-laminated timber (CLT) as the main structural element. The full-scale floor assembly consisted of CLT panels encapsulated with fiberglass wool and a single layer of 15.9 mm thick Type X gypsum board on the exposed side and with two layers of 12.7 mm thick cement board on the unexposed side. The full-scale wall assembly was constructed from CLT panels encapsulated with two layers of 15.9 mm thick Type X gypsum board on both faces. Nine thermocouples were installed on the unexposed face of both assemblies to monitor the temperature rise throughout the test and nine deflection gauges were installed on each assembly to monitor deformations. The superimposed load applied on the floor assembly was 9.4 kN/m² and the load imposed on the wall assembly was 449 kN/m. The fire endurance period of the full-scale floor assembly was 128 minutes and that of the full-scale wall assembly 219 minutes. Both the full-scale floor assembly and the full-scale wall assembly failed
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Strength and Stability of Cross-Laminated-Timber Walls at Short and Long Term

Strength and Stability of Cross-Laminated-Timber Walls at Short and Long Term

Strength and Stability of Cross Laminated Timber walls at short and long term This PhD thesis addresses the issue of CLT wall buckling. These wooden panels, made of boards which are glued cross-wise, are more and more used in construction. The current trend of the market is to design high-rise buildings which raises the issue of the compressive strength of such walls. It turns out that wood is a highly anisotropic material. Especially, the shear stiffness and strength perpendicular to the grain (rolling shear) are much weaker than in the direction parallel to the grain. This high contrast requires more elaborate design criteria than classical tools used in timber engineering. This work is organized in two main parts. First, the equivalent rolling-shear behavior of a CLT layer is investigated. Bounds are established for the stiffness of an equivalent layer using a theoretical approach. These bounds are validated by means of a new experimental set-up which allows the measurement of the rolling shear stiffness with less variability than the classical single lap shear test. In the second part, this data is used in the buckling analysis of CLT walls with increasing refinements. First, the linear buckling load of a thick plate without imperfection is established. This load is based on a new higher-order plate theory and reveals that the critical load based on a thin plate theory (Kirchhoff-Love) cannot predict correctly the strength of CLT walls. Then, the influence of imperfections is introduced adapting the classical approach from Ayrton and Perry to the case of a Timoshenko beam. This extension reveals that a new design criterion has to be satisfied under buckling which is specific to CLT. Finally, this analysis is extended to long term loads assuming a simple creep law and leading to a new simple design criterion which may be easily introduced in current design codes.
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Mechanical behavior of regularly spaced Cross Laminated Timber panels : Modeling and experimental validation in ambient and fire conditions

Mechanical behavior of regularly spaced Cross Laminated Timber panels : Modeling and experimental validation in ambient and fire conditions

opposite lamination of transverse layers leads to higher shear strengths while changing their orientation. At values of θ between about 10 ◦ and 40 ◦ , all the CLT configurations of both slenderness present sharp drops in the failure load. Further analysis proved that in this range of θ, the transverse layers are submitted to torsional effects which produce high in-plane shear stresses, leading to an unexpected plane shear failure (LN) of layers. When testing crosslam panels in bending having slenderness 18 with configuration 1b, Buck et al (2016) found a variation of failure modes from bending or rolling shear at θ = 0 ◦ to bending or longitudinal shear θ = 45 ◦ , that is very close to the failure mode transition angle showed in Figure 2.11. The associated failure load was found to be about 30% higher than the failure mode of CLT with classical orthogonal lamination. Not surprisingly, considering the uni-axial bending configuration, the Glulam-like plate lay-up having all layers parallel to the bending direction, returns the best bending behavior. The favorable effect of rotating the transverse layers on the CLT mid-span deflection is more evident at low slenderness ratios, which are not very common in practical applications. Only thick CLT plates show increasing failure loads when ro- tating their transverse layers up to about 40 ◦ . After that lamination angle, plane shear stresses within cross layers increase drastically and lead to a failure load drop. Unless dealing with a thick panel and a dimensioning criterion driven by deflection, the low gains when varying transverse layer orientation make these configurations awkward to exploit. The predicted behavior of these innovative configurations of crosslam are qualitatively in agreement with the experimental results of Buck et al (2016).
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Apparent sound insulation in cross-laminated timber buildings

Apparent sound insulation in cross-laminated timber buildings

Thus, the direct sound transmission loss of the bare separating CLT wall or floor (and the in-situ sound transmission loss for each bare CLT flanking surface) is taken as equal to the [r]

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Solutions for mid-rise wood construction: apartment fire test with encapsulated cross laminated timber construction: Test APT-CLT: report to Research Consortium for Wood and Wood-Hybrid Mid-Rise Buildings

Solutions for mid-rise wood construction: apartment fire test with encapsulated cross laminated timber construction: Test APT-CLT: report to Research Consortium for Wood and Wood-Hybrid Mid-Rise Buildings

Nine thermocouples were located on the unexposed side of the floor between the single layer of gypsum board (ceiling) in the lowest (first) storey and the CLT panels in the floor assemb[r]

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Fire demonstration: cross-laminated timber stair/elevator shaft

Fire demonstration: cross-laminated timber stair/elevator shaft

As shown in Figure 14 and Figure 16 , nine thermocouples were installed on the 16 mm thick Type X gypsum board face layer at the interface with the air gap behind the lightweight stee[r]

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Fire endurance of exposed cross-laminated timber floor for tall buildings

Fire endurance of exposed cross-laminated timber floor for tall buildings

2 Test Specimen 2.1 Full-scale floor assembly The floor assembly, which measured 4815 mm (15'-10") in length by 3607 mm (11'-10") in width, was constructed from three panels of 175 mm thick 5-ply CLT of grade E1 manufactured by Nordic. The panels were aligned such that the grain of the outer layers of timber (on both the exposed and unexposed sides) ran along the length of the floor assembly. The CLT panels were joined on the unexposed side with strips of 12.7 mm thick plywood nailed on each panel every 300 mm (starting at 150 mm from the edge of the assembly) with common 75 mm metal nails. Figure 1 and Figure 2 show drawings of the full-scale floor assembly and details of its spline joints and nailing schedule.
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Predicting the fire-resistance of cross-laminated timber assemblies

Predicting the fire-resistance of cross-laminated timber assemblies

L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB. World Conference on Timber Engineering 2012 [Proceedings], 2012 READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE. https://nrc-publications.canada.ca/eng/copyright

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Mechanical behaviour of unclassified timber walls against horizontal forces

Mechanical behaviour of unclassified timber walls against horizontal forces

1. Introduction Timber walls are the structural system in the buildings that designed for the purpose of resisting lateral loads and transmitting these forces to the foundations in a ductile behavior [1]. According to the European Standard EN 594, [2] the timber shear wall consists of timber frame and sheathing board connected together by fasteners. The sheathing board can be from different materials such as Gypsum, Plywood, Fibre board and OSB [3]. In this study, the methodology of cross planks wall has been investigated experimentally against the lateral load and an elastic analytical model has been created to describe the behavior of these walls and calculating the load carrying capacity.
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Solar timber kilns: State of the art and foreseeable developments

Solar timber kilns: State of the art and foreseeable developments

Quality control of the product is now carried out by monitoring humidity and controlling the flow of drying air via control variables (VP). The different entities then improve their efficiency. In accordance with the next two laws (law 2: energy conductivity and law 3: coordination of rhythms), we note that insulation in the kilns has got better and better. The insulating materials derive from resources available in the local environment. The notion of rhythm can be found in arrangement 3 where the alternating day/night rhythm is taken into account. The use of strategically placed fans which in most cases draw in air in front of the timber stacks serves a similar purpose.
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Timber construction methods for roof stacking: Classification and comparative analysis

Timber construction methods for roof stacking: Classification and comparative analysis

Figure 1: Case Studies around Europe classified and analysed 3.1 BUILDING MATERIALS Existing buildings with roof stacking cases were characterized by two different structural systems. Buildings that return back to the nineteenth century and early twentieth century had load bearing constructional system counting on the exterior massive walls, while buildings from late twentieth century had skeleton structure out of reinforced concrete or steel structure [31]. Building materials that have been involved in the process of roof stacking for a structural purpose have been documented throughout the 60 different analyzed cases. Even though multiple materials have been listed, it was possible to classify them under 4 main types; reinforced concrete, steel, timber, and composite (a mixture of steel and timber), while the structure of the existing buildings were found in 3 main building materials; Masonry, reinforced concrete and steel as shown in Figure 4.
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BONDING PERFORMANCE OF TROPICAL MULTI SPECIES GLUED SOLID TIMBER

BONDING PERFORMANCE OF TROPICAL MULTI SPECIES GLUED SOLID TIMBER

KEYWORDS: Tropical species, Glued Solid Timber, Cracking, Stress intensity factor, Energy release rate. 1 INTRODUCTION 123 The stabilization of environmental effects, harmful to our environment, today requires the preservation of tropical forests such as that of Gabon in the Congo Basin, which is one of the true lungs of the planet. One solution is to maximize the mechanical strength of the currently debited species by incorporating lower quality ones into the GST structures in order to sustain service structures. This technique minimizes losses due to sawing, maximizes the mechanical strengths of the structural elements obtained and, therefore, allows to control the costs of wood construction still considered high in view of the immense resource’s forests available to the country. Previous studies have already shown the feasibility of using composites glued from tropical woods and also that GST resistance depends on the position and the density of individual lamella or DUO or TRIO combinations met structural requirements [1,2].
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Deforestation--policies toward a more sustainable tropical timber industry

Deforestation--policies toward a more sustainable tropical timber industry

Along these lines, N- the World Bank, the United Nations Development Programme and the World Resources Institute stated in their 1985 Tropical Forests: A Call for Action [r]

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Time-based combinatorial auction for timber allocation and delivery coordination

Time-based combinatorial auction for timber allocation and delivery coordination

(e.g., sawing, pulp and paper, cabinet, wood floor, furniture, engineered wood product) that transform timber of various types into different products. The practical consequence of such a diverse market is that each bidder may be interested in only part of a stand instead of the entire stand. Our combinatorial model therefore allows bidders to bid not only on entire forest stands, but also on any subset of products (i.e., mix of species and quality) of these stands. Consequently, because each product is sold individually, a combinatorial auction model allows the auctioneer to allocate separately each product in order to maximize revenue. However, bidders cannot bid on part of a product (i.e., a portion of the available volume of a product). Their bids must cover all or nothing of the products available for sale in the stand. For instance, a bidder may want to make an offer for all the available volume of all quality levels of a specific species. In practice, this is not a problem for bidders as volumes available are smaller than their transformation capacity. Furthermore, logs can be stored for a while, before they deteriorate. Consequently, the implementation of such an auction model could lead to many winners with complementary bids in each stand for sale.
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Behaviour of lightweight-framed timber construction under elevated temperatures

Behaviour of lightweight-framed timber construction under elevated temperatures

P = π (1) where P cr is the elastic buckling-load (N), E is the modulus of elasticity of the resisting member (MPa), I is the moment of inertia (mm 4 ), and KL is the effective stud length (mm), with K = 1 in this case. The values of the moment of inertia and modulus of elasticity change with time. For the moment of inertia, the temperature profile and pre-set charring temperature provide an estimation of the remaining cross-section of the stud, thus allowing for calculation of the time-dependent moment of inertia. For the modulus of elasticity, the change with temperature is obtained from the literature [4]. Structural failure is assumed to occur when the load applied on the wall exceeds the buckling load. The out-of- plane deflection of the stud, as predicted for a hinged-hinged eccentric column, can be calculated by considering the stud as a beam-column structure. The out-of-plane deflection, y, at any height x on the stud at any time, is:
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