Lecture on the new horizon of architecture created by technology of cross laminated timber
https://www.jstage.jst.go.jp/article/jwpa/44/4/44_... [Design/Architectural aspects] [Journal Article] 2018
Chikai Igarashi
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Tensile Performance of the Wood Screw Joint with Steel Plate and Cross Laminated Timber
https://www.jstage.jst.go.jp/article/jaee/16/3/16_... [Connectors] [Journal Article] 2016
Shoichi Nakashima, Yasuhiro Araki, Shiro Nakajima, Hiroshi Isoda
Tensile loading tests of wood screw joint with steel plate and cross laminated were performed. There are two types of tests, the one is single joint shear test, and the other is multiple joint tensile test. The targets of the experiments are the effect of the grain direction and the effect of edge of the laminae which is not glued. The parameters for single joint tests are loading directions and material properties, and exist of border of layers. The parameters for multiple joint tests are loadi...

Development of CLT Panels Bond-In Method for Seismic Retrofitting of RC Frame Structure
https://www.jstage.jst.go.jp/article/aijs/81/726/8... [Seismic Performance] [Journal Article] 2016
Ryota Haba, Akihisa Kitamori, Takuro Mori, Takeshi Fukuhara, Takaaki Kurihara, Hiroshi Isoda
Many RC buildings built before 1981 need seismic retrofit at present in Japan. Installing new RC shear walls or steel braces in RC frame is one of the seismic retrofit techniques. In this paper, the new type of seismic retrofit method using CLT panels as shear walls is proposed. In this method, setting small CLT panels in RC frame and bonding each panel and panel to RC frame with epoxy resin, panels compose shear walls. The advantages of this technique are: There are less dust, noise, and vibrat...

Influence of Edge Bonding and Gaps between Laminae of CLT on Pull-Out Properties of LSB
https://www.jstage.jst.go.jp/article/aijt/23/54/23... [Bonding/Adhesives] [Journal Article] 2017
Makoto Nakatani, Takuro Mori
An influence of edge bonding between laminae, edge gaps between laminae without edge bonding, and edge distance from LSB to egde of a lamina, on pull-out properties of LSB joint embedded into CLT parallel to the grain direction was investigated and confirmed following characteristics. 1. Edge bonding was no effect on pull-out properties. 2. Pull-out properties of LSB embedded into a gap decreased with increasing width of the gap. 3. The edge distance was no effect on pull-out properties, if it ...

Two-hour Fireproof Performance of Cross Laminated Timber (CLT) Covered with Fire-retardant Impregnated Wood
https://www.jstage.jst.go.jp/article/jwrs/65/1/65_... [Fire Performance] [Journal Article] 2019
Toshiro Harada, Daisuke Kamikawa, Atsushi Miyatake, Kenta Shindo, Nobuaki Hattori, Keisuke Ando, Masayuki Miyabayashi
In order to develop 2-hour-fireproof cross laminated timber (CLT) floor and wall structures, covering them with wood impregnated with fire-retardant agent was studied. In the fire test of the CLT wall specimen, two layers of fire-retardant impregnated wood (Cryptomeria japonica D. Don) were alternately laminated with screws to the load-bearing CLT and a fire test was conducted for 2 hours. The total thickness of the covering material was 90 mm. However, the CLT burned due to early drop-off of th...

Proposal of Analysis Model of CLT Structure for Small Width Panel and Accuracy Verification Intended
https://www.jstage.jst.go.jp/article/aijs/82/741/8... [Mechanical Performance] [Journal Article] 2017
Motoshi Sato, Hiroshi Isoda, Yasuhiro Araki, Takafumi Nakagawa, Tatsuya Miyake
In Japan, recently some research projects on CLT (Cross Laminated Timber) construction are conducted to establish the law on the design method of CLT buildings suited with the Japanese regulations of seismic design. However, at the present moment, building with CLT construction have to be structurally designed only under “Approval route” where seismic performance of objective building is verified through the time history response analysis to obtain the approval by the minister of MLIT (Ministry ...

Estimation of Strength Properties of Tensile Bolt Joint for CLT Construction
https://www.jstage.jst.go.jp/article/aijs/81/726/8... [Connectors] [Journal Article] 2016
Kei Suzuki, Kenji Kobayashi, Kenji Aoki, Masahiro Inayama, Takahiro Tsuchimoto
Cross Laminated Timber (CLT) panel is consisted of several layers of lumber stacked crosswise and glued together on their surfaces. In Europe, mid-to-high-rise building using CLT has been already built. Recently, CLT structure attracts attention in Japan as one of the means to promote Wooden Public Buildings. Since the lamina can utilize small or middle diameter wood as the raw materials, expansion of CLT demand would promote local forestry and wood industry. There are various joint methods of C...

Bending Properties of Mixed-Species, Three-Ply CLTs (Cross-Laminated Timbers) with Inner Layer of Sugi
https://www.jstage.jst.go.jp/article/jwrs/60/6/60_... [Raw Materials] [Journal Article] 2014
Takashi Goto, Akira Fukushima, Shigeo Nakayama, Takeshi Furuno
Two types of mixed-species three-ply CLTs (Cross-Laminated Timbers) composed of hinoki-sugi-hinoki and akamatsu-sugi-akamatsu were manufactured in this study. The relationships between modulus of dynamic elasticity using frequency (Efr) of logs or lamina graded visually for knots, and modulus of elasticity (MOE) of edge-glued laminae were investigated. Moreover, mixed-species three-ply CLTs were examined by static bending tests to clarify the bending properties. The results are summarized as fol...

Embedment and Shear Strengths of Cross Laminated Timber and Their Dependence on Angular Orientation
https://www.jstage.jst.go.jp/article/jwrs/60/4/60_... [Mechanical Performance] [Journal Article] 2014
Shoichi Nakashima, Akihisa Kitamori, Kohei Komatsu
In order to evaluate the dependence of angular orientation of Cross Laminated Timber (CLT) in terms of embedment and shear strengths, we derived a prediction formula and compared it with experimental results. The assumptions used in the formula based on independence of each layer are: (a) For embedment of circular steel bar against the CLT, the total embedment strength is the average strength of each layer. (b) Embedment strength of a layer inclined to the loading direction is expressed by Hanki...

OS0405 The Image Displacement and Strain Measurement in Wooden Laminated Panel under Static Load
https://www.jstage.jst.go.jp/article/jsmekanto/201... [Mechanical Performance] [Journal Article] 2016
Kota Kobayashi, Takaaki Iiduka, Mami Wada, Akihisa Kitamori, Hirosi Isoda, Tasusi Niitsu
The digital image correlation method can measure the strain in the vibration and strength testing of the structure. In general, the strain measurement with digital image correlation is performed by applying a random pattern on the specimen as a target. However, when the strain of the specimen is increased, the collapses of the pattern occur and the strain measurement may be unsuccessful. In the load examination that a strain has more than several percent, there are a few measurement cases with t...

Study on Floor Impact Sound Reduction Effect by Double Ceiling System with Cross Laminated Timber Panels
https://www.jstage.jst.go.jp/article/aije/82/736/8... [Vibration/Acoustic Performance] [Journal Article] 2017
Manabu Tanaka, Tsuyoshi Murakami, Yusuke Kasai, Makoto Kawai
In order to improve the floor impact sound insulation of a cross laminated timber (=CLT) floor slab, several variations of double ceiling systems with cross laminated timber panels of its thickness 90mm were attached under the CLT floor slab. These floor and ceiling specimens were installed in the laboratory, and their floor impact sound levels were measured. Results of those experiments are as follows. (1) In case of attaching a double ceiling system of CLT panels of panel thickness 90mm with...

Lateral Structural Performance of Narrow Size Cross Laminated Timber Connected With Tensile Bolts
https://www.jstage.jst.go.jp/article/aijs/81/721/8... [Connectors] [Journal Article] 2016
Sota Miura, Hirosi Isoda, Takahiro Tsuchimoto, Takahumi Nakagawa, Akihisa Kitamori, Kei Suzuki, Chihiro Tsuda
Shear wall tests of single CLT wall of which size is 1x3m were conducted to evaluate the shear performance and 4m width shear wall with opening tests consisting of double 1x3m of CLT panels and hanging panels were also conducted. Tensile bolts were used as connection between the shear wall and foundation, shear wall and hanging wall, and top-bottom of shear walls. Simple tensile tests for every bolt joint, compression, shear and bending tests for CLT panel were conducted to calculate the load-di...

Experimental Study on Airborne Sound Insulation of Cross Laminated Timber Panel Walls
https://www.jstage.jst.go.jp/article/aije/81/730/8... [Vibration/Acoustic Performance] [Journal Article] 2016
Manabu Tanaka, Yusuke Kasai, Tsuyoshi Murakami, Shoji Kawatani
The purpose of this study is to estimate the airborne sound insulation performance of partition walls with cross laminated timber panels (=CLT panels). Results of sound insulation experiments in the laboratory are as follows. (1) In case of a partition wall without slit between CLT panels, its sound transmission loss increases monotonically to frequency up to 3150 Hz band. Regression line formula is applicable in this frequency range with a high correlation coefficient. (2) In case of partitio...

An Experimental Study on Keyed Beam Design Method for Two-Way Flat Slab Composed of Cross Laminated Timber
https://www.jstage.jst.go.jp/article/aijt/24/57/24... [Mechanical Performance] [Journal Article] 2018
Katsuhide Murakami, Azusa Mimatsu, Yoshisato Esaka, Masao Shiozaki, Kenji Komatsu, Masahide Murakami
Authors have developed a two-way flat slab system that is composed of double layered Cross Laminated Timber (CLT) in order that strong axial directions of CLT can be orthogonally arranged in the slab. Glued-in-rod (GIR) joint system is adopted for joining between the CLTs. Performance of GIR joint systems in several parts of the slab is investigated by using element experiments in tensile, and performance of CLT keyed beam for the CLT flat slab is investigated by using actual slab experiments in...

Measurement of Thermal Performance of CLT Building Made From Hokkaido Larch
https://www.jstage.jst.go.jp/article/aijt/24/58/24... [Other] [Journal Article] 2018
Taro Mori, Atsushi Takano, Wataru Oshima, Takeyoshi Uematsu
In recent years, CLT (Cross Laminated Timber) has attracted attention as domestic forestry revitalization and reduction of LCCO2 of buildings are required. Hokkaido Larch accounts for 30% of the planted forests in Hokkaido. For that reason, CLT buildings using Hokkaido Larch are important for the utilization of forest resources and reduction of LCCO2 in Hokkaido. In this report, we report on the result of examining the thermal performance which has a big influence on energy reduction during oper...

Bond Qualities and Test Methods of Wood Adhesives for Structural Wood-based Materials
https://www.jstage.jst.go.jp/article/jwrs/62/2/62_... [Bonding/Adhesives] [Journal Article] 2016
Shin-ichiro Tohmura
Use of engineered wood products, particularly structural glued laminated timber and/or cross-laminated timber (CLT), is indispensable for recent large-scale wooden buildings. Durability of adhesion of these materials is quite important for assurance of reliable mechanical properties throughout their service life. Therefore, only some highly reliable adhesives are permitted for use. Resorcinol resin adhesive has been used for a long time as a load-bearing structural wood adhesive. In addition, ne...

Bond Qualities and Test Methods of Wood Adhesives for Structural Wood-based Materials
http://www.rinya.maff.go.jp/j/riyou/koukyou/pdf/ho... [Bonding/Adhesives] [Journal Article] 2016
Shin-ichiro Tohmura
Use of engineered wood products, particularly structural glued laminated timber and/or cross-laminated timber (CLT), is indispensable for recent large-scale wooden buildings. Durability of adhesion of these materials is quite important for assurance of reliable mechanical properties throughout their service life. Therefore, only some highly reliable adhesives are permitted for use. Resorcinol resin adhesive has been used for a long time as a load-bearing structural wood adhesive. In addition, ne...

Development of Timber Shear Wall in Steel Frame Structure
https://www.jstage.jst.go.jp/article/aijt/24/57/24... [Alternative/Hybrid Configurations] [Journal Article] 2016
Nobuhiko Akiyama, Shigefumi Okamoto, Tomohiro Morimoto, Masahide Murakami
We developed a timber shear wall in steel frame structure and　estimated the required performances to be introduced in the 5 storey building. Firstly, we designed the shear walls of this system to satisfy the requirements and conducted the full-scale shear tests to grasp the characteristics of the failure behaviors and the actual properties of the walls. Secondly, we proposed the analytical model and compared to the test results to verify the possibility for predicting them. It was concluded that...

In-Plain Shear Test of Joint of CLT Floor Adapting CSTS System
https://www.jstage.jst.go.jp/article/aijt/24/56/24... [Mechanical Performance] [Journal Article] 2018
Masanori Fujita, Mayo Otaki, Yuki Okoshi, Takamasa Kikuchi, Kazuhisa Koyano, Mamoru Iwata
In light of the global environment, the authors proposed a building system comprising steel and timber (Hereafter referred to as CSTS), which consist of rolled section steels and timbers. A design method of the CSTS uses the concept of a damage controlled structure and its mechanical model is established based on the previous tests. In this study, we propose floor structure adapting for the CSTS using cross laminated timber. In-plane shear test of the joint which are consisted of unheaded studs ...

Development of CLT manufacturing technology as the new use of the Akamatus for promotion of tree species conversion
https://www.jstage.jst.go.jp/article/jfsc/129/0/12... [Raw Materials] [Journal Article] 2018
Yukihiro Goto, Hironori Taniuchi
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