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Normal stress distribution of timber-concrete composite panels with an adhesive shear connection under thermal and humidity loadings

https://research.thinkwood.com/en/permalink/catalogue3390
Year of Publication
2021
Topic
Mechanical Properties
Material
Timber-Concrete Composite
Author
Bajzecerová, V.
Kanócz, J.
Kormaníková, E.
Karla, V.
Orolin, P.
Vranay, F.
Organization
University of Košice
Year of Publication
2021
Format
Journal Article
Material
Timber-Concrete Composite
Topic
Mechanical Properties
Keywords
Hygrothermal Load
Hymidity
Temperature
Research Status
Complete
Series
BioResources
Summary
Humidity and temperature conditions have a substantial influence on the stresses and total deformation of timber-concrete composite panels, especially in terms of the high rigidity of the shear connection. In the present research, the normal stresses that resulted from the hygrothermal load of timber-concrete composite panels with an adhesive shear connection were analyzed. Three timber-concrete composite panel specimens were placed in controlled climate conditions. Strains in two orthogonal directions were measured. The stress distribution resulted from an approximate analytical calculation model. The results show that the highest stresses occurred near the shear connection. An increase in timber moisture content by 2.1% was predicted to result in exceeding the flexural tensile strength in the concrete perpendicular to the timber grain direction. At an outdoor temperature range, stresses influenced only by the temperature alone will possibly not cause a failure of timber or concrete. Under winter environmental conditions, the stress in timber can possibly reach 12% of the bending strength of the timber used.
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Cross-laminated timber design by flattened bamboo based on near-infrared spectroscopy and finite element analysis

https://research.thinkwood.com/en/permalink/catalogue3391
Year of Publication
2021
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Li, Chao
Zhang, Lixin
Ma, Xinyu
Wang, Xilong
Organization
Northeast Forestry University
Year of Publication
2021
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Bending Test
Finite Element Analysis
Near-infrared Spectroscopy
Bamboo and Wood Composite
Research Status
Complete
Series
BioResources
Summary
Bamboo-wood composite cross-laminated timber (BCLT) is a new kind of wood structure material. Studies of the mechanical properties of BCLT have the potential to improve its utilization. Compared with the traditional testing method, this paper designs a fast and effective nondestructive testing method. Three types of composite BCLT plates were designed and made. Multi-point sampling of unit-converted timber was done using a 900-1700 nm NIR spectrometer. Mechanical properties of the unit converted timber were obtained through a four-point bending experiment. The data set consisted of near-infrared spectrum data and mechanical property data. The NIR prediction model was obtained by partial least squares method. The coefficients of determination for the density, MOR and MOE prediction models were 0.88, 0.88, and 0.85, respectively. Finally, the finite element modeling analysis of BCLT plate was carried out according to the element material prediction model, and the prediction of mechanical properties of BCLT plate was achieved. For the three BCLT plates, the prediction error of the finite element model was less than 10%, showing that the finite element analysis method is feasible to predict the mechanical properties of BCLT plate.
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Is Cross-Laminated Timber (CLT) a Wood Panel, a Building, or a Construction System? A Systematic Review on Its Functions, Characteristics, Performances, and Applications

https://research.thinkwood.com/en/permalink/catalogue3387
Year of Publication
2023
Topic
General Information
Material
CLT (Cross-Laminated Timber)
Author
Araujo, Victor De
Aguiar, Fabricio
Jardim, Pedro
Mascarenhas, Fernando
Marini, Lucas
Aquino, Vinicius
Santos, Herisson
Panzera, Tulio
Lahr, Francisco
Christoforo, André
Organization
Federal University of São Carlos
São Paulo State University
University of Coimbra
Federal University of São João del Rei
University of São Paulo
Publisher
MDPI
Year of Publication
2023
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
General Information
Keywords
Forest Products
Engineered Wood Products
Industrialized Buildings
Research Status
Complete
Series
Forests
Summary
Cross-laminated timber (CLT) has been widely discussed as a relevant industrialized construction solution. Numerous publications have considered CLT as a structural wood-based panel, but other documents have mentioned it as a building or even a construction system. Many authors address its application in multistory buildings, although single-family houses and lower building applications have become desirable topics as well. Given these gaps, this review study addresses a systematic method to evince the functions of cross-laminated timber in construction. The elucidation and discussion were led by technical and scientific contents through publications present in scientific websites and the Google web search engine. Intricate perceptions about the knowledge and reference of CLT functions were identified. From prospections, it was possible to state that CLT is a timber-forest product created in Europe, whose function acts as a structural composite panel of the engineered wood product category. However, CLT has been mentioned by many publications as a building or a construction system. Suggestions were raised to clarify to all readers with respect to misconceptions, and elucidate the construction systems capable of using it as the main resource. Discussions evinced the characteristics and potentials of this wood product. Even with its increasing application in tall buildings, the commercial application of CLT in low-rise buildings may be boosted by the possibility of large-scale production of industrialized houses.
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Structural Behaviour of Aluminium–Timber Composite Beams with Partial Shear Connections

https://research.thinkwood.com/en/permalink/catalogue3388
Year of Publication
2023
Topic
Mechanical Properties
Material
LVL (Laminated Veneer Lumber)
Application
Beams
Author
Chybinski, Marcin
Polus, Lukasz
Organization
Poznan University of Technology
Publisher
MDPI
Year of Publication
2023
Format
Journal Article
Material
LVL (Laminated Veneer Lumber)
Application
Beams
Topic
Mechanical Properties
Keywords
Aluminium-Timber Composite Beams
Partial Shear Connection
Screws
Bending Test
Finite Element Method
Research Status
Complete
Series
Applied Sciences
Summary
In this paper, the short-term behaviour of innovative aluminium–timber composite beams was investigated. Laminated veneer lumber panels were attached to aluminium beams with screws. Recently conducted theoretical, experimental, and numerical investigations have focused on aluminium–timber composite beams with almost full shear connections. However, no experiments on aluminium–timber composite beams with partial shear connections have yet been conducted. For this reason, composite action in composite beams with different screw spacing was studied in this paper. Four-point bending tests were performed on aluminium–timber composite beams with different screw spacing to study their structural behaviour (ultimate load, mode of failure, load versus deflection response, load versus slip response, and short-term stiffness). The method used for steel–concrete composite beams with partial shear connection was adopted to estimate the load bearing capacity of the investigated aluminium–timber composite beams. The resistance to sagging bending of the aluminium–timber composite beams with partial shear connections from the theoretical analyses differed by 6–16% from the resistance in the laboratory tests. In addition, four 2D numerical models of the composite beams were developed. One model reflected the behaviour of the composite beam with full shear connection. The remaining models represented the composite beams with partial shear connections and were verified against the laboratory test results. Laminated veneer lumber was modelled as an orthotropic material and its failure was captured using the Hashin damage model. The resistance to sagging bending of the aluminium–timber composite beams with partial shear connections from the numerical analyses were only 3–6% lower than the one from the experiments.
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What really matters in multi-storey building design? A simultaneous sensitivity study of embodied carbon, construction cost, and operational energy

https://research.thinkwood.com/en/permalink/catalogue3389
Year of Publication
2023
Topic
Environmental Impact
Energy Performance
Author
Gauch, H.L.
Dunant, C.F.
Hawkins, W.
Serrenho, A. Cabrera
Organization
University of Cambridge
University of Bath
Publisher
Elsevier
Year of Publication
2023
Format
Journal Article
Topic
Environmental Impact
Energy Performance
Keywords
Multi-storey Buildings
Embodied Carbon
Construction Cost
Frame Material
Research Status
Complete
Series
Applied Energy
Summary
Buildings account for over one-third of global emissions and energy use. Meeting climate pledges will require achieving high operational energy efficiency with low embodied impacts in new construction. Yet, a systematic identification of the relative influence of building design parameters on both operational and embodied efficiencies has rarely been attempted. In this paper we explore for the first time the sensitivity of a wide range of design and operation parameters in terms of embodied carbon, construction cost, as well as heating and cooling loads for multi-storey buildings. We devised a model to estimate the relative importance of a large set of input variables, describing a building’s shape, size, layout, structure, ventilation, windows, insulation, air, and use for residential and office multi-storey buildings, across different climates. We found that increasing building compactness, using steel or timber instead of concrete frames, lowering window-to-wall ratio, choosing the most suitable glazing, and employing mechanical ventilation with heat recovery are the most important measures to decrease embodied emissions and operational energy. The most significant trade-offs with construction cost were found for the choice of frame material and in the decision whether to install mechanical ventilation. We estimate that 28–44% of yearly heating and cooling energy and 6 Gt cumulative embodied CO2e until 2050 could be saved in multi-storey buildings, without employing new technologies.
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The influence of the opening size on the shear performance of the cross-laminated timber (CLT) walls

https://research.thinkwood.com/en/permalink/catalogue3381
Year of Publication
2021
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Author
Zhang, Daiyuan
Shen, Liming
Zhu, Xudong
Zhang, Sujun
Gong, Meng
Organization
Nanjing Forestry University
Yangzhou Polytechnic Institute
University of New Brunswick
Year of Publication
2021
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Topic
Mechanical Properties
Keywords
Opening
Experimental Study
Research Status
Complete
Series
BioResources
Summary
Cross-laminated timber is a wood product with excellent fire resistance and mechanical performance that is often used in tiny houses. Using the ASTM standard E564, the shear performance of cross-laminated timber wall panels, with and without openings, were investigated in this study. The specimens were made of spruce-pine-fir IIc lumber and installed on a test platform using high-strength bolts passing through them. This connection mode limited the displacements obtained in the test, primarily the shear displacements and rocking displacements. By comparing the static load test data of the three specimens with openings and the one without an opening, it was found that openings reduced the shear strength and shear stiffness. For the same sized rectangular opening, the shear stiffness of the cross-laminated timber panel was less when the wider side was horizontal (normal to the direction of the applied force). The shear stiffness of the cross-laminated timber wall panels can be effectively improved by reinforcing the areas near the openings with metal sheets. With reinforcement, the shear strength did not change drastically, but the damage to the cross-laminated timber wall panels was significantly reduced.
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Evaluation of the bending performance of glued CLT-concrete composite floors based on the CFRP reinforcement ratio

https://research.thinkwood.com/en/permalink/catalogue3382
Year of Publication
2022
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Timber-Concrete Composite
Application
Floors
Author
Song, Yo-Jin
Baek, Seong-Yeob
Yu, Seok-Hoon
Kim, Dong-Hyeon
Hong, Soon-I1
Organization
Kangwon National University
Year of Publication
2022
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Timber-Concrete Composite
Application
Floors
Topic
Mechanical Properties
Keywords
Gamma Method
CFRP
Bending Test
Research Status
Complete
Series
BioResources
Summary
A study was conducted on the reinforcement of cross-laminated timber (CLT) concrete composite floors with carbon fiber reinforced plastic (CFRP) to improve its mechanical performance and reliability in wood composite structures. A four-point bending test evaluation was completed on three types of cross-laminated timber concrete composite floors produced with different carbon fiber reinforced plastic reinforcement ratios (33%, 66%, and 100%) on the entire surface of the tensile portion. An increase in the carbon fiber reinforced plastic reinforcement ratio of the composite floors led to an increased bending capacity and a slightly improved yield performance. In the case of a composite floor with a reinforcement ratio of 33%, premature failure occurred in the elastic region due to defects of the CLT such as knots and slopes of the grain. Failure mode analysis revealed that tensile and shear failure coexist when the composite floor has a CFRP reinforcement ratio of 33%. In contrast, reinforcement ratios of 66% and 100% prevented premature failures in the elastic region caused by defects and induced a consistent failure mode. These reinforcement effects reduced the variability in the increased bending capacity of the composite floors and improved the accuracy of the theoretical prediction design via the –method. Meanwhile, the shear connections between the cross-laminated timber and concrete via epoxy adhesive exhibited full-composite behavior without being affected by the reinforcement ratio.
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Shear performances of hybrid notch-screw connections for timber-concrete composite structures

https://research.thinkwood.com/en/permalink/catalogue3383
Year of Publication
2022
Topic
Connections
Mechanical Properties
Material
Timber-Concrete Composite
Application
Floors
Author
Shi, Benkai
Dai, Yongqing
Tao, Haotian
Yang, Huifeng
Organization
Nanjing Tech University
Southeast University
Year of Publication
2022
Format
Journal Article
Material
Timber-Concrete Composite
Application
Floors
Topic
Connections
Mechanical Properties
Keywords
Hybrid Notch-screw Connection
Ductility
Slip Modulus
Push-Out Tests
Research Status
Complete
Series
BioResources
Summary
This paper presents the push-out experimental results of hybrid notch-screw (HNS) connections for timber-concrete composite structures. A total of 7 groups of specimens were designed and tested. The experimental parameters included the loading constraint conditions (i.e., the test specimens were loaded either in local compression or in uniform compression), shapes of notches in the wood, screw number in notch, notch width, and the inclusion of a self-tapping screw reinforcement for timber or not. The experimental results were discussed in terms of failure modes, ultimate strength, slip moduli, and ductility. The yield strengths and ductility factors were determined based on the load-slip curves according to existing standards. The experimental results showed that both the shear timber width and the self-tapping screw reinforcement played important roles in terms of the ultimate strengths, ductility, and deformability. Rectangular notched connections with screw reinforcements displayed timber shear failure coupled with brittle failure. With the trapezoidal notch, the ductility of the connections improved, coupled with a decrease in the slip modulus. The self-tapping screw reinforcement for shear timber could greatly improve the ductility performance of the HNS connections. The slip modulus models for the connection with vertical deep notches were provided, which were in agreement with the experimental results.
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Experimental static and seismic behaviour of glulam beam-to-column connection with screwed-in threaded rod joints

https://research.thinkwood.com/en/permalink/catalogue3384
Year of Publication
2021
Topic
Mechanical Properties
Seismic
Material
Glulam (Glue-Laminated Timber)
Author
Yang, Huifeng
Wang, Chaochao
Hu, Junbin
Tao, Haotian
Liu, Jiwei
Tang, Liqiu
Shi, Benkai
Organization
Nanjing Tech University
Southeast University
Year of Publication
2021
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Topic
Mechanical Properties
Seismic
Keywords
Threaded Rods
Beam-to-column Connection
Energy Dissipater
Research Status
Complete
Series
BioResources
Summary
To evaluate the static and seismic behaviour of glulam beam-to-column connections with screwed-in threaded rods, nine specimens grouped in three were tested under both monotonic and reversed cyclic loads. The failure modes, moment resistance, initial rotation stiffness, ductility, and energy dissipation capacity of the developed connections were investigated. The results indicated that the developed beam-to-column connections showed superior structural performance. Furthermore, with the introduction of a steel bracket, the hybrid screwed-in threaded rod connection features larger stiffness, higher load-carrying capacity, remarkable ductility, and better energy dissipation capacity. The main failure modes included the yielding of steel brackets, as well as the yielding or rupture of the threaded rods, which indicated a ductile behaviour. The connection specimens with steel columns showed larger stiffness than those with glulam columns, which is reasonable for the bigger compressive deformation of glulam columns.
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Experimental study on notched connectors for glulam-lightweight concrete composite beams

https://research.thinkwood.com/en/permalink/catalogue3385
Year of Publication
2020
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Timber-Concrete Composite
Author
Jiang, Yuchen
Hu, Xiamin
Hong, Wan
Zhang, Jun
He, Fangqian
Organization
Taihu University of Wuxi
Nanjing Tech University
Year of Publication
2020
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Timber-Concrete Composite
Topic
Mechanical Properties
Keywords
Notched Connection
Push-out Test
Shear Capacity
Slip Modulus
Research Status
Complete
Series
BioResources
Summary
A new type of structural element, the timber-concrete composite beam, exhibited excellent structural performance. The notched connector is widely used in timber-concrete composite systems as a result of its considerable shear capacity and stiffness. Six groups of push-out tests were performed to investigate the shear performance of the notched connectors for the timber-concrete composite beams, with consideration to the varying concrete types, the shear length of the timber, and whether the notch was reinforced. From the test results, the notched connectors that corresponded to the shear fracture of concrete or timber had a low shear capacity and poor ductility. Notched connectors that simultaneously failed at the concrete slab (via shear force), as well as at the lag screw reinforcement point during bending presented the greatest shear capacity. This was followed by the notched connectors that exhibited diagonal-compression failure at the concrete slab. Screw fasteners in the notch were shown to improve the strength, ductility, and post-peak behavior of the notched connectors. In addition, the concrete type, the shear length of the timber, and whether the notch was reinforced were found to have no major influence on the slip modulus of the notched connectors.
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Performance evaluation of a novel cross-laminated timber made from flattened bamboo and wood lumber

https://research.thinkwood.com/en/permalink/catalogue3386
Year of Publication
2021
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Wei, Peixing
Wang, Brad Jianhe
Li, Hao
Wang, Libin
Gong, Yingchun
Huang, Suyong
Organization
Nanjing Forestry University
Southwest Forestry University
Year of Publication
2021
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Flattened Bamboo
Axial Compression
Bending Performance
Research Status
Complete
Series
BioResources
Summary
A novel flattened bamboo-wood composite cross-laminated timber (CCLT) made from flattened bamboo and hemlock lumber was developed, and its mechanical performance was investigated and quantified in this work. The results demonstrated that the CCLT columns and control hemlock CLT counterparts had nearly equal axial compression strength, but the CCLT yielded a higher compression modulus of elasticity (MOE). Additionally, the CCLT compression behaviors were not significantly affected by the height. Compared with hemlock CLT, the CCLT exhibited a slightly higher flatwise bending MOE and strength in the major strength direction. Furthermore, the MOE and strength of the CCLT under edgewise bending were 17.3% less and 16.2% greater than those under flatwise bending, respectively. The load-carrying capacity of the CCLT was mainly governed by the interfacial failure between the bamboo and wood, in which no rolling shear failure was observed. Those features are unique for the new CCLT for engineered applications.
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A literature review on cold-formed steel-timber composite structures

https://research.thinkwood.com/en/permalink/catalogue3378
Year of Publication
2021
Topic
General Information
Material
CLT (Cross-Laminated Timber)
Steel-Timber Composite
Author
Moritani, Fabiana Y.
Martins, Carlos E. J.
Dias, Alfredo M. P. G.
Organization
Universidade de Coimbra
Year of Publication
2021
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Steel-Timber Composite
Topic
General Information
Keywords
Cold-Formed Steel
Composite Structures
Hybrid Structure
Research Status
Complete
Series
BioResources
Summary
State-of-the-art steel-timber composite structures (STC), using cold-formed steel (CFS) and cross-laminated timber (CLT), are considered in this review. Literature on this type of construction solution is reviewed to provide an overview of the characteristics and advantages of STC. Previous experimental and numerical studies with STC structures, mainly composite solutions with CFS beams and CLT panels, are discussed to assess the behavior of this structural typology. A comprehensive description of the connection systems performance in different STC structures is also provided. Furthermore, the design and analytical methods currently available are presented. Likewise, details on aspects related to dynamic properties and fire resistance are discussed.
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Comparative study on connection properties of shear bolt and screw of thin cross-laminated timber panel

https://research.thinkwood.com/en/permalink/catalogue3379
Year of Publication
2023
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Author
Zhang, Daiyuan
Shen, Liming
Zhu, Xudong
Zhang, Sujun
Gong, Meng
Gao, Yuewen
Organization
Nanjing Forestry University
University of New Brunswick
Year of Publication
2023
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Connection Properties
Bolt
Screw
Research Status
Complete
Series
BioResources
Summary
Cross-laminated timber (CLT), a wood product with excellent shear resistance, is often used in modern timber constructions. Using the standards ASTM D1761-12 (2020) and NDS-2012 (2012), this study investigated the connection properties of shear bolts and screws in CLT panels. The specimens were made from spruce-pine-fir lumber and installed on a test platform using one high-strength bolt or eight screws, and then an upward load was applied to the top of the specimen. The results showed that the bolt connection provided a higher ultimate bearing capacity and elastic stiffness. The bolt exhibited virtually no deformation, and the CLT panel did not noticeably deteriorate when the connection was damaged. The distance between the bolt hole and the bottom of the CLT specimen and the angle between the outer-layer grain direction of the CLT panel and the load direction were both measured. Changes in the ductility coefficient value had an obvious effect on the connection performance of the shear bolts when the outer-layer grain direction of the CLT panel was consistent with the load direction. Contrastingly, when the outer-layer grain direction of the CLT panel was perpendicular to the load direction, the effect was negligible, and the yield load was nearly unchanged.
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Bending performance of cross-laminated timber-concrete composite slabs according to the composite method

https://research.thinkwood.com/en/permalink/catalogue3380
Year of Publication
2021
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Timber-Concrete Composite
Application
Floors
Author
Baek, Seung-Youp
Song, Yo-Jin
Yu, Seok-Hoon
Kim, Dong-Hyeon
Hong, Soon-I1
Organization
Kangwon National University
Year of Publication
2021
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Timber-Concrete Composite
Application
Floors
Topic
Mechanical Properties
Keywords
Shear Connection
CFRP
Failure Mode
Research Status
Complete
Series
BioResources
Summary
Bending strength tests were conducted of cross-laminated timber (CLT)-concrete composite slabs according to the shear connection method and carbon fiber reinforced plastic (CFRP) reinforcement. The bending strength of the composite slab that was shear-connected with an epoxy adhesive was 17% higher than that of a composite slab that was shear-connected with a self-tapping screw. In addition, the CLT-concrete slip of the former composite slab was also measured as 20% lower than the latter under the same load, showing a behavior close to that of a full composite. Both shear connection methods generated a failure in a low load-deformation section when there was a defect in the outermost tensile laminae of the CLT. In contrast, the CFRP reinforcement in the tension part of the composite slab suppressed the failure at the defect in the outermost tensile laminae. This reinforcement effect increased the reliability of the bending performance of the composite slab by preventing the failure of the composite slab while in a constant failure mode. Furthermore, the slip of the composite slab decreased 49% after its reinforcement with CFRP, showing a behavior close to that of a full composite.
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Shear stiffness of notched connectors in glue laminated timber-concrete composite beams under fire conditions

https://research.thinkwood.com/en/permalink/catalogue3375
Year of Publication
2022
Topic
Mechanical Properties
Material
Timber-Concrete Composite
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Shi, D.
Hu, X.
Zhang, J.
Du, H.
Organization
Nanjing Tech University
Year of Publication
2022
Format
Journal Article
Material
Timber-Concrete Composite
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Mechanical Properties
Keywords
Notched Connection
Shear Stiffness
ISO Fire
Research Status
Complete
Series
BioResources
Summary
Shear connectors ensure effective interaction between wood beams and concrete slabs of composite beams, and their properties noticeably affect the fire resistance of timber-concrete composite beams. To investigate the shear stiffness of notched connectors in glued laminated timber (GLT)-concrete composite beams under fire conditions, 16 shear tests were conducted. The effects of fire duration and notch length on shear properties of the connectors for a given spacing were studied. The fire tests indicated that the reduction of the notch length from 200 mm to 150 mm remarkably affected the failure mode of the shear specimens, changing from compression failure of notched wood to shear failure of notched concrete. The increase in fire duration reduced effective width of the notched wood, negatively affected the shear stiffness and shear capacity of the connectors, and the shear stiffness decreased more rapidly. The notch length did not have a substantial effect on the shear stiffness of connectors. Based on the experimental results, an analytical model to estimate the shear stiffness of notched connectors in GLT-concrete beam under fire conditions was established.
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Influence of glue-free zones on the withdrawal capacity of glued-in steel threaded rods

https://research.thinkwood.com/en/permalink/catalogue3376
Year of Publication
2023
Topic
Mechanical Properties
Connections
Author
Pugovics, Karlis
Spulle, Uldis
Arhipova, Irina
Grants, Edvins
Klancbergs, Kristians
Organization
Latvia University of Life Sciences and Technologies
Year of Publication
2023
Format
Journal Article
Topic
Mechanical Properties
Connections
Keywords
Glued-in Steel Treaded Rod
Glue-free Zone
Withdrawal Capacity
Destructive Testing
Research Status
Complete
Series
BioResources
Summary
The hidden nature of a glued-in rod joint presents considerable challenges with regards to quality control, and there has been minimal research on the subject to fully understand the influence of defects on the joint performance. In this study, voids in adhesive line or glue-free zones were simulated in various depths of the embedded rod, and the results were compared to a reference sample population without defects. Withdrawal capacity of glued-in steel threaded rods were lower compared to reference group samples without gluing defects, when glue simulated voids or glue-free zones were positioned in the middle part and upper (closer to sample crosscut surface) part of the glued-in rods. And no difference was observed of simulated glue-free zones in the lower (the deepest) part, closer to the end of the glued-in rod, compared to reference group samples without gluing defects.
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Review of connections for timber-concrete composite structures under fire

https://research.thinkwood.com/en/permalink/catalogue3377
Year of Publication
2022
Topic
Fire
Material
Timber-Concrete Composite
Author
Shi, D.
Hu, X.
Hong, W.
Zhang, J.
Du, H.
Organization
Nanjing Tech University
Year of Publication
2022
Format
Journal Article
Material
Timber-Concrete Composite
Topic
Fire
Keywords
Shear Connection
Research Status
Complete
Series
BioResources
Summary
A timber-concrete composite structure has the advantages of energy saving, environmental protection, and low carbon, and has wide application prospects. However, the effects of fire on timber-concrete composite structures are complicated. It is important to study the fire performance of connections and their influencing factors for the promotion and application of timber-concrete composite structures. This paper summarizes the research progress of connections for timber-concrete composite structures under fire. Firstly, research on the performance of connections in timber-concrete composite structures under fire is introduced, including screwed connections, notched, and grooved connections, and steel truss plate connections. Secondly, the calculation methods focused on connections of timber-concrete composite structures under fire are introduced. Finally, the main points of modeling timber-concrete composite structures under fire are also briefly introduced.
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Experimental and theoretical investigation on shear performances of glued-in perforated steel plate connections for prefabricated timber–concrete composite beams

https://research.thinkwood.com/en/permalink/catalogue3373
Year of Publication
2023
Topic
Mechanical Properties
Material
Timber-Concrete Composite
Application
Beams
Floors
Author
Yang, Huifeng
Lu, Yan
Ling, Xiu
Tao, Haotian
Shi, Benkai
Organization
Nanjing Tech University
Southeast University
Publisher
Elsevier
Year of Publication
2023
Format
Journal Article
Material
Timber-Concrete Composite
Application
Beams
Floors
Topic
Mechanical Properties
Keywords
Glued-in Perforated Steel Plate
Prefabricated Concrete Slab
Slip Modulus
Experimental Study
Research Status
Complete
Series
Case Studies in Construction Materials
Summary
Glued-in perforated steel plate (GIPSP) connections demonstrate significant shear strength and high slip modulus. Consequently, they indicate substantial potential for application in timber–concrete composite (TCC) structures according to the emerging tendencies in high-storey and large-span buildings. However, the application pattern in prefabricated TCC structures and the theoretical analysis of the shear performances of GIPSP connections are highly deficient. This hinders the application of this type of shear connection. In this study, the shear performances of GIPSP connections were evaluated using push-out tests. Ten groups of push-out specimens with different steel plate numbers, steel plate lengths, and concrete slab types were tested. The concrete slab types investigated in the experiments included a prefabricated concrete slab and cast-in-situ concrete slab. The experimental results were discussed in terms of the failure mode, load-carrying capacity, and slip modulus. The theoretical models for the load-carrying capacity related to the associate failure mode were discussed based on an analysis of the failure mechanisms. In addition, design proposals with regard to the load-carrying capacity and slip modulus of the GIPSP connection were presented. The research results can provide design guidance for TCC beams using GIPSP connections and prefabricated concrete slabs.
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Free
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Dimensional behavior of nail-laminated timber-concrete composite caused by changes in ambient air, and correlation among temperature, relative humidity, and strain

https://research.thinkwood.com/en/permalink/catalogue3374
Year of Publication
2023
Topic
Moisture
Material
NLT (Nail-Laminated Timber)
Timber-Concrete Composite
Author
Hwang, Sung-Wook
Chung, Hyunwoo
Lee, Taekyeong
Ahm, Kyung-Sun
Pang, Sung-Jun
Kim, Ji Yong
Bang, Junsik
Jung, Minjung
Oh, Jung-Kwon
Kwak, Hyo Won
Yeo, Hwanmyeong
Organization
Seoul National University
Year of Publication
2023
Format
Journal Article
Material
NLT (Nail-Laminated Timber)
Timber-Concrete Composite
Topic
Moisture
Keywords
Correlation
Dimensional Change
Moisture Content
Monitoring
Research Status
Complete
Series
BioResources
Summary
A timber-concrete composite (TCC) slab composed of nail-laminated timber (NLT) and topping concrete (TC) was developed for flooring applications. The NLT was laminated alternately with lumber and plywood. To investigate the dimensional behavior of the TCC slab, the temperature, relative humidity (RH), and dimensional changes of the slab exposed to outdoor air were monitored for 205 days. Temperature change was directly transmitted to both components, and RH change was gradually transmitted to the NLT. Concrete pouring caused a sharp increase in NLT width, which was the laminating direction of the nails. This resulted from swelling of the wood because of the moisture in the concrete mixture and loosening of the nail lamination. The member composition for the nail-laminating system, fastener type, and concrete volume help to secure the dimensional stability of the NLT. Cracks in the TC caused width deformation, which was recovered by drying shrinkage of the TC. Correlation analysis among temperature, RH, and strain indicated that dimensional changes in NLT correlated strongly with RH, while those in TC correlated strongly with temperature. The correlation between longitudinal strain in the TC and strain in the three directions of the NLT was attributed to the notches designed for mechanical connection.
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Free
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A life cycle and product type based estimator for quantifying the carbon stored in wood products

https://research.thinkwood.com/en/permalink/catalogue3371
Year of Publication
2023
Topic
Environmental Impact
Author
Wei, Xinyuan
Zhao, Jianheng
Hayes, Daniel J.
Daigneault, Adam
Zhu, He
Organization
Oak Ridge National Laboratory
University of Maine
Chinese Academy of Sciences
Publisher
Springer
Year of Publication
2023
Format
Journal Article
Topic
Environmental Impact
Keywords
Carbon Pool
Carbon Storage
Life Cycle
Wood Products
Research Status
Complete
Series
Carbon Balance and Management
Summary
Background Timber harvesting and industrial wood processing laterally transfer the carbon stored in forest sectors to wood products creating a wood products carbon pool. The carbon stored in wood products is allocated to end-use wood products (e.g., paper, furniture), landfill, and charcoal. Wood products can store substantial amounts of carbon and contribute to the mitigation of greenhouse effects. Therefore, accurate accounts for the size of wood products carbon pools for different regions are essential to estimating the land-atmosphere carbon exchange by using the bottom-up approach of carbon stock change. Results To quantify the carbon stored in wood products, we developed a state-of-the-art estimator (Wood Products Carbon Storage Estimator, WPsCS Estimator) that includes the wood products disposal, recycling, and waste wood decomposition processes. The wood products carbon pool in this estimator has three subpools: (1) end-use wood products, (2) landfill, and (3) charcoal carbon. In addition, it has a user-friendly interface, which can be used to easily parameterize and calibrate an estimation. To evaluate its performance, we applied this estimator to account for the carbon stored in wood products made from the timber harvested in Maine, USA, and the carbon storage of wood products consumed in the United States. Conclusion The WPsCS Estimator can efficiently and easily quantify the carbon stored in harvested wood products for a given region over a specific period, which was demonstrated with two illustrative examples. In addition, WPsCS Estimator has a user-friendly interface, and all parameters can be easily modified.
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Free
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