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Round timber construction With the Globe Theatre, which was completed in 2023, Coburg has a new highlight of a special kind. The new theatre is not only a four‐storey circular building, but also almost a pure timber construction. It serves as a temporary solution during the general renovation of the venerable Landestheater in the historic city centre. The building ensemble is located close to the city centre on the site of the former goods station and consists of a main building and three adjoining buildings in timber construction. The actual theatre building rises strikingly into the air as a circular structure. The three outbuildings adjoin the main building one behind the other and are connected to each other by a glazed corridor. The circular building made of cross‐laminated timber, glulam and floor slabs in timber‐concrete composite dry construction was a challenge for all planners and builders. ZÜBLIN Timber from Aichach was responsible for ensuring that the planning, production, delivery and installation of the timber‐concrete composite ceilings ran smoothly. The new interim venue has been very popular since its opening and will continue to be used for events after the reopening of the state theatre. [ABSTRACT FROM AUTHOR]

Copyright of China Forest Products Industry is the property of China Forest Products Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Buildings account for approximately 40% of global energy consumption annually, with substantial energy use occurring during both the construction and operation phases. The energy required for the production of construction materials contributes significantly to the overall energy intensity of the building sector. This underscores the critical need for materials with low embodied energy to mitigate the environmental impact associated with building construction and operation. Cross-laminated timber, massive timber product with excellent load-bearing capabilities, is becoming popular in mid-rise buildings worldwide. CLT's environmental, economic, and social benefits surpass traditional materials, and its use is widespread in Europe, America, Canada, and Australia. However, no mid-rise CLT buildings have been constructed in the UAE yet. This study aims to investigate and identify the barriers to adopting CLT as a building material and construction system for mid-rise buildings in the UAE. A qualitative approach is used to study stakeholders' behavior towards CLT construction. A comprehensive questionnaire survey and conversational interviews are conducted, with the responses analyzed to identify patterns and themes. The results identify the existing barriers within the construction industry impeding the adoption of cross-laminated timber (CLT). Additionally, the study discusses strategies necessary to facilitate the widespread adoption of CLT. These findings will inform future research aimed at addressing the obstacles to constructing mid-rise buildings using CLT in the UAE. [ABSTRACT FROM AUTHOR]

Cross-laminated timber (CLT) fails in the outermost tensile lamina under bending loads, or rolling shear failure occurs in the Minoir direction lamina. This study investigated the effect of lamina width (90 mm, 120 mm), modulus of elasticity (MOE), and placement of major direction lamina on the shear strength of Larix kaempferi Carr CLT. The shear test was conducted using the short span bending test. Results showed that the specimen with 90 mm width of lamina underwent rolling shear failure at the minor direction lamina. The specimen with 120 mm width of lamina had suppressed rolling shear failure and failed at the outermost tensile lamina, which resulted in 52% higher shear strength compared to the 90 mm width specimen. CLT with high MOE placed in the outermost tensile lamina had increased shear strength. The specimen with four laminas in the major direction had both the highest strength and the lowest reliability due to the high standard deviation. This suggested that the width of the larch lamina and the MOE affect the strength of CLT. The CLT strength obtained using the FEA and the theoretical analysis were compared with the measured strength values. [ABSTRACT FROM AUTHOR]

Wood is a commonly used building material with numerous advantages over other construction products. However, in engineered wood products such as cross-laminated-timber and laminated veneer lumber moisture absorption can lead to decay, swelling, deformation, and glue line failures, diminishing their properties. Understanding moisture intrusion processes in these materials can aid manufacturers, engineers, and architects in developing effective moisture management strategies during and after construction. The porosity of CLT 3P sections was 56.5%, higher than CLT 2P sections at 36.8%. True density varied among species, with radiata pine, southern pine, and shining gum measuring 1358, 1411, and 1031 kg/m3, respectively. True density values for CLT 3P, CLT 2P, and LVL were 1202, 837, and 1406 kg/m3, respectively. The species and sample type significantly influenced porosity and density values, crucial for future moisture modelling and predicting moisture gain/loss during wetting and drying processes. Moisture sorption and desorption properties were examined for Australian timber species, CLT, and LVL at different temperatures. LVL samples exhibited higher moisture content and dimensional changes, possibly due to improved moisture transfer facilitated by lathe checks. CLT samples demonstrated greater anisotropic behaviours than those of LVL samples. The product type and sample type had significant effects on equilibrium moisture content values. [ABSTRACT FROM AUTHOR]

The proper choice of raw materials and manufacturing parameters for Cross Laminated Timber is essential to promote the proper bonding of the lamellas, aiming at their application in construction. However, few Brazilian species are currently used in the production of Cross Laminated Timber. The aim of this work was to characterize the bonding quality of four Brazilian reforestation species (Pinus elliottii (pino ellioti), Eucalyptus grandis (eucalipto), Toona ciliata (toona) and Acrocarpus fraxinifolius (lazcar)) in the manufacture of Cross Laminated Timber with two-component polyurethane adhesive and five different pressure levels (from 0,1 MPa to 1,3 MPa). Bonding quality was evaluated through delamination and glue line shear tests based on the European standard. Delamination was affected by the wood species, and the best adhesion occurred for the Cross Laminated Timber manufactured with Pinus elliottii (pino ellioti) and Acrocarpus fraxinifolius (lazcar) at the bonding pressure of 0,7 MPa. Cross Laminated Timber bonding pressure did not affect the percentage of wood in the shear test fractured surface, whereas higher density Cross Laminated Timber showed higher percentages. [ABSTRACT FROM AUTHOR]

Cross laminated timber (CLT), with its typical orthogonal layering and exposure to out-of-plane bending, develops inherent rolling shear stresses. These stresses need to be checked during the ultimate limit state design process. With the ongoing revision of Eurocode 5, a discussion regarding the characteristic value of the rolling shear strength of CLT has arisen. One obstacle in the discussion is seen in the lack of harmonized regulations concerning how to determine rolling shear properties. This circumstance manifests in the greatly diverging test results of different institutions testing the rolling shear strength. The paper at hand aims to propose a candidate for such harmonized regulations. To achieve this, the most common test setups, such as the inclined shear test, three- and four-point bending tests, etc., were numerically and experimentally investigated. Within the numerical investigations, a comparison of the most common calculation methods (Timoshenko beam theory, modified γ-method, Shear Analogy Method, and Finite Element Analysis) for evaluating rolling shear stresses was included. In the experimental program, parameters such as the specimen width, number, and thickness of the cross layer(s), shear length, optional reinforcement against the stresses perpendicular to the grain, and the overall test setup were varied. It was found that the used test setups themselves and the area of the cross layer(s) (shear length, number, and thickness of the cross layer(s)) have a major impact on the rolling shear strength. In contrast, no effect was found from the calculation methods. Based on these findings and on a database of approx. 300 four-point bending rolling shear tests on CLT specimens from five well-established CLT manufacturers, a model for the regulation of the rolling shear strength of CLT is proposed, in combination with a corresponding four-point bending test setup. Afterwards, with two additionally conducted four-point bending test series, the proposed model is successfully validated. The conclusions and recommendations in respect to the test setup (four-point bending), evaluation procedure (Timoshenko beam theory), reference characteristic rolling shear strength, and the model, which allows adapting the reference rolling shear strength to individual conditions, are seen as a worthy basis for a more objective discussion on this topic. [ABSTRACT FROM AUTHOR]

Featured Application: Ecological alternative for wall–ceiling connections with cross-laminated timber elements. No additional metal fasteners are required for connecting and suspending the ceiling elements. In timber construction, there are still no standardized wall–ceiling system connectors made of wood for cross laminated timber construction (CLT). Based on experimental investigations of the bar-shaped dovetail connections, a wood–wood system connection was developed at the University of Innsbruck. First, the traditional dovetail connection for bar-shaped beam connections was investigated. The findings showed the high potential of force transmission in the flank area, especially for beam connections of the same height, where the height of the pre-timber is too small. To date, the load-bearing capacity of the flanks has not been taken into account in the calculation methods. To increase the force transmission paths in the base of the tenon, it was shaped in steps. This led to a load redistribution and thus delayed the failure of the connection. The knowledge gained formed the basis for an independent connecting element that resulted in the so-called "double dovetail". The connector is a three-dimensional, statically effective double dovetail element. The wood system connector is made of block-glued laminated veneer lumber (LVL) and is manufactured in a CNC-milling process. The results of the tests showed the high performance potential of the LVL system connector, which can play an important role in future timber construction. [ABSTRACT FROM AUTHOR]

A strengthening of cross laminated timber (CLT) by a composite effect with steel girders can act as a sustainable option to replace concrete or composite slabs for spans of more than 7 m. The efficiency of a composite structure is strongly influenced by the stiffness of the shear connectors. Therefore, fully threaded screws and shear studs were investigated in double push‐out tests. The screws are inclined to increase their stiffness and are rotated within the drilled hole towards the web, so that a multidimensional load situation with both axial and shear loads results. The shear studs are placed in openings of the CLT and cast in with mortar. The shear tests confirmed that their load bearing behaviour can basically be described with existing analytical calculation approaches. The findings were extended in large‐scale 4‐point bending tests to investigate the bending behaviour of the composite beam. [ABSTRACT FROM AUTHOR]

This paper examines the response of steel‐timber hybrid (STH) lateral stability systems for medium‐rise buildings. A ten‐storey baseline STH structure was designed to codified procedures and compared with a steel‐concrete composite structure. Detailed numerical models were constructed in which specific constitutive representations were assigned to steel‐timber and timber‐timber connections. Parametric investigations on the STH structure were carried out in which the cross laminated timber panel layups, timber shear wall length, and connection characteristics were modified. The study indicated that the STH structure had larger lateral deformations compared to the steel‐concrete structure, both within code limits. For the same design loads, the reduction in self‐weight from the steel‐concrete structure to the STH structure was 73.1%, whilst the floor depth was reduced by 17.2%, respectively. Parametric studies showed that the lateral response of STHs is generally improved with the effective thickness of the timber infill panel and is influenced by the panel layup. Increasing the shear wall length generally enhances the lateral stiffness, yet the overall performance is reduced with the increase of panel connections. The reduction in self‐weight, member sizes and replacement of the concrete with timber led to a reduction in embodied carbon of more than 32.7% whilst achieving similar structural performance. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering & Architectural Faculty of Eskisehir Osmangazi University / Eskişehir Osmangazi Üniversitesi Mühendislik ve Mimarlık Fakültesi Dergisi is the property of Eskisehir Osmangazi University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Forest Products Industry is the property of China Forest Products Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The proper choice of raw materials and manufacturing parameters for Cross Laminated Timber is essential to promote the proper bonding of the lamellas, aiming at their application in construction. However, few Brazilian species are currently used in the production of Cross Laminated Timber. The aim of this work was to characterize the bonding quality of four Brazilian reforestation species (Pinus elliottii, Eucalyptus grandis, Toona ciliata and Acrocarpus fraxinifolius) in the manufacture of Cross Laminated Timber with two-component polyurethane adhesive and five different pressure levels (from 0,1 MPa to 1,3 MPa). Bonding quality was evaluated through delamination and glue line shear tests based on the standard EN 14080 (2013). Delamination was affected by the wood species, and the best adhesion occurred for the Cross Laminated Timber manufactured with Pinus elliottii and Acrocarpus fraxinifolius at the bonding pressure of 0,7 MPa. Cross Laminated Timber bonding pressure did not affect the percentage of wood in the shear test fractured surface, whereas higher density Cross Laminated Timber showed higher percentages.

Cross Laminated Timber (CLT) is thriving as a wood engineered material across the globe. As demand increases, lamstock solutions become necessary to supply the demand, and low-quality lumber has been pointed as an option to solve this problem. Nevertheless, low-quality lumber has significant warping that spreads skepticism towards bonding failure due to out-of-plane defects. This article aims to investigate bonding failure using a pressure mapping, built with a Pressure Prediction Model, comparing theoretical results with block shear and cyclic delamination tests observations. Block shear test indicates no significant difference of wood failure results among different pressures zones using 2-ply lamination samples with a manufacturing press of 414 kPa. Cyclic delamination occurred in an insignificant frequency for samples in all pressure zones analyzed. In summary, for this study, the bonding strength could resist the residual stresses caused by warping experimentally. The findings of this investigation can encourage CLT manufacturers to utilize undervalued and low-grade materials such as small diameter timber (SDT) as a feedstock and contribute to the sustainability of CLT market growth.

Compression Perpendicular to Grain (CPG) is a crucial aspect of timber design, particularly with the advent of engineering wood products like Cross Laminated Timber (CLT), often used in point-supported structures. After many years of discussion, the mechanics-based model by Van der Put has finally been included in the new Eurocode draft. This model offers a more systematic approach to design with a solid theoretical foundation for stress dispersion. However, there is still a need for improvement, especially in two areas: accounting for the capacity increment associated with increasing levels of deformation and determining the maximum effective height to be assumed in calculating the load spreading in deep timber elements. In this paper, the authors focus on these two areas of improvement for GLT, solid timber and CLT timber products. They analyse the data of two extensive experimental campaigns conducted at Norsk Treteknisk Institutt (Norwegian Institute of Wood Technology) and at the Norwegian University of Science and Technology (NTNU) on Glued Laminated Timber (GLT), Solid Timber (ST) and CLT. Additionally, they validated a parametric finite element (FE) model in Abaqus to assess the effect of the height of the timber element on stress distribution. A parametric approach developed in Abaqus aims to find the optimal height threshold to be assumed in the new code formulation. • An extensive experimental campaign on ST, GLT and CLT is conducted. • Support type, load position, load plate size and loading scenario influence is analysed. • The capacity increment associated with increasing levels of deformation is assessed. • A linear dependence of the average capacity on the deformation level was observed. • The maximum effective height to be assumed in calculating the load spreading is determined. [ABSTRACT FROM AUTHOR]

Understanding the burning rate (mass loss rate, MLR) of timber products is essential in characterizing the ignition characteristics, fire size, and extinction phenomena experienced by timber. Key parameters for timber, such as self-extinction criteria, are presented throughout literature. These parameters are often determined using bench-scale experiments in relatively low trial quantities (e.g., n = 3). This study investigates the influence of trial quantity on the observed statistical variation in key burning rate metrics for timber products (e.g., peak MLR, MLR at extinction). Experiments were performed using a conical heater to conduct 100 repeat trials at incident heat fluxes of 20 kW/m2, 40 kW/m2, and 50 kW/m2 on 12.7 mm (0.5 in.) thick ACX cross laminated plywood samples. Significant variability was observed in trials conducted at 40 kW/m2 due to bimodal behavior where 39% of samples experienced self-extinction and the remaining 61% of samples sustained combustion until burnout (i.e., complete pyrolysis of the material). The MLR at extinction for the trials at 40 kW/m2 displayed nearly double the magnitude compared to trials conducted at 20 kW/m2 due to the breakdown of the semi-infinite solid condition. The results from this work illustrate the significance of large trial quantities when investigating complex phenomena. • 300 experiments conducted on plywood samples using a bench-scale conical heater. • Experiments were conducted under a range of external heat fluxes. • Statistical analyses were conducted on the peak MLR and MLR at extinction/burnout. • Samples exposed to 40 kW/m2 were found to exhibit self-extinction and burnout. • Marginal gain in statistical uncertainty found to be minimized after 15–20 trials. [ABSTRACT FROM AUTHOR]

Moment-resisting frames provide open space and architectural flexibility, yet their application in multistorey timber buildings is limited. Research on the pullout behaviour of threaded rods screwed into timber has demonstrated high strength and stiffness. This paper presents an innovative, slip-friction, beam-to-column, moment-resisting connection, which utilizes threaded rods screwed into cross laminated timber beams and columns. The connection employs the concept of slip-friction, which has been successfully used in several steel structures and allows for energy dissipation though friction slip, hence realize a damage free energy dissipation mechanism. Four full-scale tests have been carried out, in which specimens have been first subjected to service-level cyclic loading, followed by a destructive cyclic loading. Under service-level cyclic loading, the connection featured stiffness in the range of 10,000–20,000 kNm/rad and approximately 4 % equivalent viscous damping ratio. Under destructive cyclic loading, the connection exhibited high moment capacity in the range of 164–180 kNm. Furthermore, ductile behaviour was observed with failure associated with plastic hinging in the threaded rods. Ductility ratios were estimated based on cyclic envelop curves and found to be in the range of 4.0–6.6. • A new metallic friction-based moment resisting timber connection is introduced. • The properties of the connection were investigated through four full scale tests. • The connection was tested under cyclic service-level and destructive loading. • The connection exhibited high stiffness under service-level loading. • The connection exhibited high capacity and ductility under destructive loading. [ABSTRACT FROM AUTHOR]

Cross laminated timber (CLT), with its typical orthogonal layering and exposure to out-of-plane bending, develops inherent rolling shear stresses. These stresses need to be checked during the ultimate limit state design process. With the ongoing revision of Eurocode 5, a discussion regarding the characteristic value of the rolling shear strength of CLT has arisen. One obstacle in the discussion is seen in the lack of harmonized regulations concerning how to determine rolling shear properties. This circumstance manifests in the greatly diverging test results of different institutions testing the rolling shear strength. The paper at hand aims to propose a candidate for such harmonized regulations. To achieve this, the most common test setups, such as the inclined shear test, three- and four-point bending tests, etc., were numerically and experimentally investigated. Within the numerical investigations, a comparison of the most common calculation methods (Timoshenko beam theory, modified γ-method, Shear Analogy Method, and Finite Element Analysis) for evaluating rolling shear stresses was included. In the experimental program, parameters such as the specimen width, number, and thickness of the cross layer(s), shear length, optional reinforcement against the stresses perpendicular to the grain, and the overall test setup were varied. It was found that the used test setups themselves and the area of the cross layer(s) (shear length, number, and thickness of the cross layer(s)) have a major impact on the rolling shear strength. In contrast, no effect was found from the calculation methods. Based on these findings and on a database of approx. 300 four-point bending rolling shear tests on CLT specimens from five well-established CLT manufacturers, a model for the regulation of the rolling shear strength of CLT is proposed, in combination with a corresponding four-point bending test setup. Afterwards, with two additionally conducted four-point bending test series, the proposed model is successfully validated. The conclusions and recommendations in respect to the test setup (four-point bending), evaluation procedure (Timoshenko beam theory), reference characteristic rolling shear strength, and the model, which allows adapting the reference rolling shear strength to individual conditions, are seen as a worthy basis for a more objective discussion on this topic.

This paper gives a short introduction of the development of cross laminated timber (CLT) concrete composite walls with a glued connection. In the composite walls, prefabricated ultra-high-performance concrete (UHPC) lamellas replace timber lamellas at the core layer of the CLT elements. To check the feasibility of gluing timber to UHPC small-scale shear, delamination and bonding tests were performed and showed promising results. The load bearing behaviour was analysed with centrically and eccentrically loaded tests on wall segments. Analytic modelling of the wall experiments using an effective bending stiffness, based on shear analogy method, showed a good correlation to the experimental results.

Building with cross laminated timber (CLT) has gain increased interest over the last years, but in common to other wood-based building systems, inadequate low-frequency sound insulation is seen as a problem. This paper deals with two methods to improve the sound insulation of CLT panels, normally made from spruce: 1) heavy CLT, introducing compressed, i.e. densified, spruce as well as alternative wood species, and 2) elastic layer based upon shear motion. In addition to a series of laboratory measurements, a full-scale CLT floor made of two 60 mm birch panels with a 12 mm elastic layer in between was tested in a two-room test mock-up. The results from the acoustical measurements showed that the floor has about 7 dB greater airborne and impact sound insulation for one-third octave bands, 50–3150 Hz, compared to a standard CLT floor of the same total height.

Cross Laminated Timber (CLT) has been considered a feasible and sustainable option as a building material for many building applications. However, lowering costs and the ability to use a wide spectrum of lower quality lamstock can be critical for this product growth. Off-spec timber often has a significant number of out-plane defects that prevent the lamstock from lying flat and creating an intimate bond between the corresponding CLT layers. This paper aims to introduce a mechanical model to estimate the amount of pressure that makes a warped lumber flat and allow proper contact for an adhesive bond. The difference between experimental and theoretical values were less than 5 kPa for most samples analyzed. The proposed model is an important step to allowing low-quality lumber associated with out-of-plane defects to be further explored by the wood industry in order to create new options for CLT feedstock. This is especially true when considering utilization of small diameter timber (SDT), which is often not considered a viable option for many CLT lamstocks. As a desired outcome, this could minimize losses and optimize industrial manufacturing by using low-quality materials that would positively impact the forest health and mitigate wildfires, while creating economic opportunities. [ABSTRACT FROM AUTHOR]

Nowadays, advanced hygrothermal simulation tools are available and they are widely used to predict moisture-related risks in building components, such as mold growth and increased conductive heat losses. This paper takes advantage of these capabilities to analyze moisture-related risks in the innovative wood-based retrofit solutions, developed in the ongoing H2020 "e-SAFE" project. In particular, simulations carried out through the Delphin software for the warm Mediterranean climate of Catania (Italy) allowed assessing the effectiveness of several insulating materials used in the wall assembly and the moisture-related performance determined by adopting either a waterproof membrane or a vapor barrier in convenient positions. The results show that the solutions with highly permeable and highly moisture-capacitive insulation (e.g., wood fiber) are mold free, but at the expense of increased heat losses by up to 12%, compared to dry materials). In some circumstances, foam glass or extruded polyurethane could be preferable, due to their high resistance to mold growth and their flat sorption curve. The vapor-open waterproof membrane applied to the outer side of the insulation is suggested, while a vapor barrier on the outer side of the existing wall worsens mold-related issues. [ABSTRACT FROM AUTHOR]

Determining the membrane, bending, and shear stiffness of cross-laminated timber (CLT) and innovative panels requires advanced finite element computations and homogenization techniques based on thin and thick plate theories. These computations may not be easily implemented by engineers. To address this issue, this paper implements and makes accessible a machine-learning model that directly predicts the linear elastic properties of CLT and innovative panels. First, a large database of plate stiffness moduli is built from finite element computations taking into account microstructural characteristics such as the layers' thicknesses, board width, gaps width, longitudinal modulus of elasticity, and longitudinal and rolling shear stiffness moduli of timber. Second, three approximations are built and investigated: closed-form solutions, an artificial neural network trained on the database, and another artificial neural network that uses the closed-form solutions as prior knowledge before being trained on the data. The results demonstrate the superiority of artificial neural networks with prior knowledge and a very satisfying accuracy for engineering applications. The root mean square percentage error (RMSPE) values range from 0.23% to 3.01%, and the maximum absolute percentage error (MaxAPE) values range from 1.12% to 20%. • The homogenization of a thick plate theory is applied to various CLT configurations. • A large dataset is built varying both geometric and stiffness parameters. • Artificial neural networks are trained on the dataset to provide a surrogate model. • The dataset and the artificial neural network are made available on a repository. [ABSTRACT FROM AUTHOR]

This study investigated the bending and shear strength of hybrid cross-laminated timber (CLT) manufactured from beech (Fagus orientalis) and poplar (Populus deltoides) wood using experimental and finite element methods. The CLT panels were manufactured at various span to depth ratios 6, 10, 15, 20 and 25 with width of 30 cm and thickness of 2 cm in both major and minor directions. Then, the bending and shear strength of CLTs were measured using three-point bending test according to ASTM test methods. The results indicated that with the increase of span to depth ratio of the beam from 6 to 25, the averages modulus of elasticity (MOE) and modulus of rupture (MOR) values were increased in both major and minor directions. On the contrary, the averages shear modulus (𝜏𝑚𝑎𝑥) values of specimens in both directions were decreased. Moreover, the results of finite elements showed that the amounts of stress distributions and their locations were different in major and minor directions of the beam. In the major direction, the surface layers were primarily contributed load-carrying capacity of CLT panels, while in the minor direction the middle layer played the most significant role for load-carrying capacity. In this research, it was resulted that specimens with span to depth ratio greater than 15 based on ASTM D198 can be used for calculating MOE and MOR of CLT panels. Furthermore, due to existence of lower difference than 10% between experimental and numerical results, modules of elasticity of CLTs were predictable according to finite element method. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift für Herz-, Thorax- und Gefaesschirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper gives a short introduction of the development of cross laminated timber (CLT) concrete composite walls with a glued connection. In the composite walls, prefabricated ultra-highperformance concrete (UHPC) lamellas replace timber lamellas at the core layer of the CLT elements. To check the feasibility of gluing timber to UHPC small-scale shear, delamination and bonding tests were performed and showed promising results. The load bearing behaviour was analysed with centrically and eccentrically loaded tests on wall segments. Analytic modelling of the wall experiments using an effective bending stiffness, based on shear analogy method, showed a good correlation to the experimental results. [ABSTRACT FROM AUTHOR]

The compressive strength in the major direction of cross-laminated timber CLT is the key to supporting the building load when CLT is used as load-bearing walls in high-rise wood structures. This study mainly aims to present a model for predicting the average compressive strength of CLT and promoting the utilization of CLT made out of planted larch. The densities and compressive strengths of lamina specimens and CLT samples with widths of 89 and 178 mm were evaluated, and their relationship was analyzed to build a prediction model by using Monte Carlo simulation. The results reveal that the average density of the lamina and CLT were about equal, whereas the average compressive strength of the CLT was just about 72% of that of the lamina. Width exerted no significant effect on the average compressive strength of the CLT, but homogenization caused the wider CLT to have a smaller variation than that of the lamina. The average compressive strength of the lamina could be calculated by using the average density of lamina multiply by 103.10, and the average compressive strength of the CLT could be calculated according to the compression strength of lamina in major and minor direction, therefore, a new prediction model is determined to predict the average compression strength of CLT by using the average density of lamina or CLT, the average compression strength of CLT made in this study is about 74.23 times of the average density of the lamina. The results presented in this study can be used to predict the average compressive strength of CLT by using the average density of lamina and provide a fundamental basis for supporting the utilization of CLT as load-bearing walls. [ABSTRACT FROM AUTHOR]

This paper examines the seismic behavior of CLT-steel hybrid walls at 6- and 10-story heights to increase seismic force resistance compared to conventional wooden walls. The ultra-strong shear walls proposed in this paper are called Framing Panel Shear Walls (FPSW), which are based on a robust articulated steel frame braced with CLT board panels and steel tendons. Timber structures are well-known for their ecological benefits, as well as their excellent seismic performance, mainly due to the high strength-to-weight ratio compared to steel and concrete ones, flexibility, and redundancy. However, in order to meet the requirements regarding the maximum inter-story drifts prescribed in seismic design codes, a challenging engineering problem emerges, because sufficiently resistant, rigid and ductile connections and lateral assemblies are not available for timber to meet both the technical and economical restrictions. Therefore, it is necessary to develop strong and cost-effective timber-based lateral systems, in order to become a real alternative to mid- and high-rises, especially in seismic countries. In this investigation, the dynamic response of cross-laminated timber (CLT) combined with hollow steel profiles has been investigated in shear wall configuration. After experimental work, research was also carried out into numerical modelling for simulating the cyclic behavior of a hybrid FPSW wall and the spectral modal analysis of buildings of 6- and a 10-stories with FPSW. A FPSW shear wall can double the capacity and stiffness. [ABSTRACT FROM AUTHOR]

Copyright of Annals of Warsaw University of Life Sciences - SGGW, Forestry & Wood Technology is the property of Wydawnictwo SGGW and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of timber constructions recently increased. In particular, Cross Laminated Timber floors are often used in multi-story buildings. The development of standardization processes, product testing, design of details and joints, the speed of construction, and the advantages of eco-sustainability are the main reasons why these structures play a paramount role on the international building scene. However, for further developments, it is essential to investigate sound insulation properties, in order to meet the requirements of indoor comfort and comply with current building regulations. This work presents the results obtained by in field measurements developed using different sound sources (tapping machine, impact rubber ball, and airborne dodecahedral speaker) on Cross Laminated Timber floors, changing different sound insulation layering (suspended ceiling and floating floors). Results clearly show that the influence on noise reduction caused by different layering stimulated by diverse noise source is not constant and furthermore that no available analytical model is able to correctly predict Cross Laminated Timber floors acoustic performances. [ABSTRACT FROM AUTHOR]

Experimental tests of Cross Laminated Timber (CLT) under in-plane beam loading conditions are presented. The influence of the element layup, the individual lamination width, and the beam overhang at the supports on the shear force capacity was investigated. All the CLT beams had the same gross cross section, and a 4-point-bending test setup was used. The experimentally determined load-bearing capacities are compared with the load-bearing capacities resulting from analytical methods proposed for structural design, focusing on shear failure in the crossing areas of flatwise bonded laminations (shear failure mode III). The test results indicate no or very small influence of the element layup and the lamination width on the shear force capacity. These results partly contradict the predictions of the proposed design methods. Of the three studied beam geometry parameters, the beam overhang at the support had the greatest influence on the load-bearing capacity. • Lamination width was found to have small influence on load-bearing capacity. • Element layup was found to have small influence on load-bearing capacity. • Beam overhang length was found to influence the load-bearing capacity. • Test results are partly in disagreement with available design proposals. [ABSTRACT FROM AUTHOR]

Cross-Laminated Timber (CLT) is an innovative industrial wood product, especially as a structural wall in order to meet the rigidity and strength requirements in multi-storey timber buildings. CLT members are assembled with metal connectors (angle bracket, joining plates, etc.) via nails, screws, dowels, etc. For energy-absorbing structural CLT connections, many experimental studies have been conducted on the effectiveness of the connections, especially for the earthquake prone regions. There is no scientific study in this context in Turkey yet. For this purpose; the performance of a full-scale CLT wall-to-floor specimen assembled with metal connection was experimentally investigated under axial tensile force due to bending moments of seismic loads. Domestic angle bracket, plates, and phosphate coated annular ring nails were used. All the displacements and strains were measured and collected during the test of the specimen, behavior of connection and the failure mode was observed. As a result, the back side deformation of CLT wall member was prevented with the plates for a longer period compared with no-plate case and the withdrawal resistance of from CLT floor increased through phosphate coated annular ring nails and extra three nails in the corner of angle bracket on the front side. Domestic metal connectors were used in the experiments to support the metal industry and the production with low cost. This study is a pioneering study in Turkiye on the experimental performance of CLT connections for the structural utilization. The results are promising, and the further experimental researches will continue for the most effective connection type.