Experimental study of lateral resistance of bolted joints using Japanese cedar (Cryptomeria japonica) treated with resin impregnation

Abstract

The development of wooden joints possessing high resistance performance has become an important issue for the construction of newer buildings. This study attempts to strengthen the lateral resistance of bolted joints using the previously reported plasticizing technique. This technique consists of two processing stages: incising the surface of the wood using an ultraviolet wavelength short-pulse laser and impregnating the resin into the incised area. This technique makes it possible to plasticize only a local part of the wood surface. Bolted joint specimens were assembled using plasticized wood around the bolt hole, and the lateral tests were conducted. Acrylic monomer and urethane prepolymer were used as the impregnating resins and their incision depths were set as 4 and 10 mm. When the lateral load acted parallel to the grain, changes in the lateral resistance characteristics were observed, especially for the stiffness and yield load. For example, when acryl was used, and the incision depth was 10 mm, an increment of 73% in the yield load was observed, as compared to the non-impregnated specimens. The specimen groups impregnated with acryl exhibited greater changes in their properties than those using urethane. When loaded perpendicular to the grain, an increase in properties were observed; however, these increments were lower than those of the groups loaded parallel to the grain.

Embedment properties of Japanese cedar (Cryptomeria japonica) treated with resin impregnation

“…Although the thickness of the board was 20 mm, the incisions were created from both the top and rear facings, such that the incisions pierced the board. Other laser irradiation parameters are shown in Table 2, and were determined according to previous studies [12,13].…”

“…Based on the results, two types of resin were chosen, which hardly decreased the mechanical property of cell wall due to swelling. The chosen resins were the same as in our previous study [13]. The first was a urethane prepolymer (PS-NY6, Kotobukikakou Co., Ltd.) (hereafter, urethane).…”

“…Previously, the authors tried to apply resin impregnation to bolted joints, and significant improvements in the initial stiffness and yield load were demonstrated [13].…”

Comparison of the elastic limit and yield load of nailed joints connecting solid wood and wood-based board material

“…The first was a perfect elasto-plastic model (EPM) [13,21]. Although this method was originally proposed for analyzing wood-frame structures, there are many examples of researchers applying it to joint analyses [22][23][24][25]. The method for determining the yield load is illustrated in Fig.…”

Acrylic Resin Filling Cell Lumen Enabled Laminated Poplar Veneer Lumber as Structural Building Material

“…Therefore, the development of an environmentally friendly resin system for impregnating and filling the cell lumen is a breakthrough to solve the bottleneck problem of poplar. Water-based acrylic resins [ 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ], furfuryl alcohol resins [ 48 , 49 , 50 , 51 ], polyester resins [ 52 , 53 , 54 ] and 2D resins [ 55 , 56 , 57 ] have been studied as environmentally friendly filler modifiers to replace aldehyde resins [ 58 ].…”