The connectors for the CLT shear wall with drift pin joint were suggested. The wall composed of five layers Japanese cedar CLT, steel connectors and drift pins (diameter d = 16mm). The horizontal shear performances of the walls were evaluated by static experiment and 2D frame analysis. The experimental parameter was number and position of drift pins. Characteristic failure was shear failure on the border of the laminae. There were good agreement on initial stiffness, yield load and second stiffness between experiment and calculation.
The Japanese domestic forests have never been maintained enough, and it was a great fear that the multiple functions of the forest such as watershed conservation, the land conservation, and so on has been declined. The construction employing the cross laminates timber (CLT) panels was offered as a method of large scale building in domestic and foreign countries. However, the seismic design method of CLT panel construction has never completed. So, in order to consider the seismic design method, the shaking table tests and static lateral load tests were conducted to the modelized CLT panel construction.
This study introduces a new resilient slip friction joint for framed hybrid structures. The proposed connection has a self-centring behaviour in addition to damping characteristic. This innovative Resilient Slip Friction (RSF) joint is replaced with the conventional beam to column connections. The RSF joint provides energy dissipation...
A reduction coefficient is applied in usual design of multiple dowels type connections. The numbers of stiffeners in row is one of important factor to decide this coefficient. CLT drift pinned joint showed small orthotropy against in plane tensile load. Tensile tests of multiple drift pins joints were performed to evaluate the effect of array. Numbers of drift pins n in each specimen were same (n=12), but the arrangements were different (2 x 6, 3 x 4, 4 x 3, 6 x 2). Also the grain directions were parameters (0, 90 degrees). The reduction of initial stiffness and proportional limit load showed good agreement between theoretical prediction and experimental results.
This paper presents an experimental evaluation of the fire resistance of glued-in rod timber joints using epoxy resin, with and without modification. A heat-resistant modified resin was designed by adding inorganic additives into the epoxy resin, aiming to improve the heat resistance. Joints that were made using the modified epoxy resin at room temperature showed a bearing capacity comparable to those with commercial epoxy resin. Twenty-one joint specimens with the modified epoxy resin and six with a commercial epoxy resin were tested in a fire furnace to evaluate the fire resistance. The main failure mode was the pull-out of the rod, which is typical in fire tests of this type of joints. As to the effects of the test parameters, this study considered the effects of adhesive types, sectional sizes, stress levels, and fireproof coatings. The test results showed that the fire resistance period of a joint can be evidently improved by modifying the resin and using the fireproof coating, as the improvements reached 73% and 35%, respectively, compared with the joint specimens with commercial epoxy resin. It was also found that, for all specimens, the fire resistance period decreased with an increase in the stress level and increased with an increase in the sectional sizes.
This testing report summarises the experimental investigations on finger-jointed timber speci- mens, glued with different types of adhesives, loaded in tension and exposed to standard ISO-fire. The tests were performed as part of the project entitled “Fire safety of bonded structural timber elements” in the frame of a CTI-project (Commission for Technology and Innovation). The extensive testing programme on finger-jointed timber specimens was performed in cooperation with industry partners at the Swiss Federal Institute of Technology Zurich (ETH Zurich). The main aim of this research project is to clarify if the currently used design model for the fire re- sistance of bonded structural timber elements, such as glued-laminated timber, should consider the behaviour of adhesives at elevated temperatures. In this experimental study, different adhesives available on the market from adhesive man- ufacturer from Europe (such as Casco AG, Dynea AG, Jowat AG, Türmerleim AG, Purbond AG) were tested. Adhesives being used for structural applications as well as adhesives not certified according to current European testing standards for the use in structural applications were tested. The fire performance of 12 different adhesives - of type 1C PUR, MUF, PRF, EPI, PVAc, UF - were tested in a finger-jointed connection for cross-sections with a width of 80, 140 and 200 mm. In total, 49 fire tests were performed under ISO-fire exposure at the Swiss Federal Labora- tories for Materials Testing and Research (EMPA) in Duebendorf/ Switzerland. Two tests were conducted with specimens equipped with thermocouples to determine the temperature distribu- tion along the cross-section width. In the other tests, different parameters and their influence on the fire resistance were varied, such as the adhesive in the finger joint, the width of the specimen, the load level and the type of fire exposure on the testing lamella. The tests were performed in two test series in March and April, 2011 as well as in July and August, 2012. The second test series was extended by five additional tests with higher graded timber in August 2013. The main result from the first test series can be concluded as follows: The adhesives tested (2 x PUR, 1 x MUF) fulfil current approval criteria according to EN 301 (2013c) and EN 15425 (2008) for the use in load-bearing timber components in Europe. The adhesives fulfil at least the A7 test at 70 ° C according to EN 302-1 (2013a). Taking into account the failure pattern, no significant difference was observed between these adhesives. It could be shown that the higher loss of strength for some adhesives tested at elevated temperature does not necessarily lead to the same loss of strength in fire, since defects like knots may be dominant - depending on the strength class (grading). The main result from the second test series can be concluded as follows: No substantial difference was obtained for finger-jointed specimens glued with PRF and other structural ad- hesives. The PUR adhesive fulfilling the ASTM D7247 (2007) standard test at temperatures higher than 200 C did not reach a higher fire resistance than PUR adhesives which do not fulfil this standard. It was found that adhesives, which are used in structural timber members such as glued-laminated timber beams, need sufficient strength at lower temperatures than 200 C. iv This is especially explained by the steep temperature gradient typical for timber members such as glued-laminated timber. In addition to the fire tests, about 120 tensile tests on finger-jointed lamellas were performed at normal temperature. These lamellas were produced with the same types of adhesives as studied in the fire tests. The results of the whole investigation are summarised in this test report
In a process before being finished in a sawing factory after felled in forest, we clarified the actual situation of the carbon income and expenditure with edge materials and the fuel, and calculated the carbon balance of the house made by Nagano’s local wood. In this report, we carried out the actual survey and a hearing investigation in the laminated lumber factory and, calculated carbon balance of Japanese larch finger joint wood and glued laminated timber of eastern Nagano prefecture.