ベイヒバ製材品の強度性能 (Strength of yellow cypress lumber)

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1 (Bulletin of FFPRI) Vol.9 No.3 (No.416) September 2010 研究資料 (Research material) ベイヒバ製材品の強度性能曲げ縦圧縮縦引張りせん断めり込み 1)* 1) 1) Strength of yellow cypress lumber - Bending strength, compressive strength parallel to the grain, tensile strength parallel to the grain, shear strength parallel to the grain, and compressive strength perpendicular to the grain - Hirofumi IDO 1), Hirofumi NAGAO 1) and Hideo KATO 1) Abstract Recently, the use of yellow cypress (Chamaecyparis nootkatensis) has been increasing in constructing the foundations of a house due to its durability. However, at present, the standard strength requirements of yellow cypress that is essential for structural design have not been determined, and there is an urgent need to set rectify this. In this study, various tests were conducted on the strength of yellow cypress lumber and we collected data for use in determining its standard strength. After conducting tests on the bending strength, the compressive strength parallel to the grain, the tensile strength parallel to the grain, the shear strength parallel to the grain and the compressive strength perpendicular to the grain, we have concluded that yellow cypress should be added to the current non-graded lumber category and included among karamatsu (Japanese larch), hiba (false arborvitae), hinoki (Japanese cypress) and Port Onford cedar. Key words : yellow cypress, strength, bending strength, compressive strength parallel to the grain, tensile strength parallel to the grain, shear strength parallel to the grain, compressive strength perpendicular to the grain (Chamaecyparis nootkatensis) 1. (Chamaecyparis nootkatensis) Table 1 (, 2000) Table 2 (, 2001) 供試材 4000mm 105mm 105mm 200 ( ) 2.2 各強度試験への供試材の振り分け 10.3kN/mm % Received 18 May Accepted 9 August ) Depar t ment of Wood Engineer ing, Forest r y and Forest Products Research Instit ute (FFPR I) * Depar t ment of Wood Engineer ing, Forest r y and Forest Products Research Instit ute (FFPR I), I baraki, Japan, ; ido@ff pr i.aff rc.go.jp

2 126 IDO. H et al ( ) ( ) ( ) ( ) Table 3 Fig 強度試験 (, 2003) (2004) Fig (, 2007) 6 (630mm) 18 (1890mm) tf ( 98kN) (NMB TCM-10000) 10mm/min ( CDP-100) ( CDP-10) ( 400mm) 20 65%RH 縦圧縮試験 6 (630mm) 3000kN ( A-300-B4) 600kN mm ( CDP-10) 縦引張り試験 20 (2100mm) 950mm 2000kN ( HZS-200-LB4) mm ( CDP-10) 20 65%RH せん断試験 (, 2004) 150mm 45mm mm 3000kN ( A-300-B4) 150kN めり込み試験 6 (630mm) 90mm 3000kN ( A-300-B4) 300kN 5 2 ( CDP-50) (2008) 9 3, 2010

3 Strength of yellow cypress lumber - Bending strength, compressive strength parallel to the grain, tensile strength parallel to the grain, shear strength parallel to the grain, and compressive strength perpendicular to the grain % 75% 95% 5% 3. Table 曲げ試験 Table 9 508kg/m % 9.34kN/ mm 2 (, 2005) 11.01kN/mm kN/mm 2 (, 2006) E 0 9.0kN/mm N/mm N/mm N/mm 2 5% (, 2006) 5% 5% 26.8N/mm 2 II 26.7N/mm 2 II Table ( % ) Table Table 10 5% N/mm N/mm N/mm N/mm 2 5% JAS (, 2000) N/mm N/mm N/mm N/mm N/mm N/ mm 縦圧縮試験 Table N/mm 2 II 33.1N/mm N/mm 2 IV 28.9N/mm 2 5% 20.4N/ mm 2 II 20.7N/mm 2 (, 1996) ASTM D (ASTM International, 1998) 15% 31.9N/mm 2 15% 5% 21.7N/ mm 2 II 3.3 縦引張り試験 Table kg/m % 5% 17.7N/ mm 2 I 17.7N/mm 2 II Table % N/mm N/mm N/ mm N/mm 2 5% JAS (, 2000) N/mm N/mm N/mm N/mm N/mm N/mm 2 II N/mm N/mm N/mm 2 Bulletin of FFPRI, Vol.9, No.3, 2010

4 128 IDO. H et al せん断試験 Table 14 5% 5.21N/mm 2 I 2.4N/mm 2, 2006 Table 15 5% 5% 5% II III 2.1N/mm 2 IV 1.8N/mm 2 5% 3.5 めり込み試験 Table 16 5% 5% 4.79N/mm 2 Table 2 7.8N/ mm 2 ISO (ISO, 2005) 20mm f c,90 5% (, 2005) (, 2006) (, 2005) (Ido et al., 2007) 5% Table 17 5% f c,90 5% 4. ASTM International (1998) Standard practice for evaluating allowable properties for grades of structural lumber, ASTM D (2004),, 50, (2006),, 52, Ido, H., Nagao, H. and Kato, H. (2007) Comparison between compression strength perpendicular to the grain and shear strength parallel to the grain of Western hemlock lumber, Bulletin of FFPRI, 402, ISO (2005) Structural timber Characteristic values of strength-graded timber Sampling, full-size testing and evaluation, ISO (2005),, 55, E (2000) Fc Ft Fb Fs, (2001), (2005) <7>,, 56pp. (1996),, 51, (2003) ( ),,, (2006),,, , 399. (2007), (2006),, 56, PE009. (2005) (1),, 55, E (2008),, 369, , 2010

5 Strength of yellow cypress lumber - Bending strength, compressive strength parallel to the grain, tensile strength parallel to the grain, shear strength parallel to the grain, and compressive strength perpendicular to the grain Bulletin of FFPRI, Vol.9, No.3, 2010

6 130 IDO. H et al Table 1. Standard strength requirements for non-graded lumber Species Standard strength requirements Compression parallel to the grain Tension parallel to the grain Bending Shear parallel to the grain I Akamatsu, Kuromatsu, Douglas fir Softwood Hardwood II Karamatsu, Hiba, Hinoki, Port Onford cedar III Tsuga, Western hemlock IV Momi, Ezomatsu, Todomatsu, Benimatsu, Sugi, Western red cedar, Spruce I Kashi II Kuri, Nara, Buna, Keyaki Table 2. Standard requirements for compressive strength perpendicular to the grain for lumber Softwood Hardwood Species Akamatsu, Kuromatsu, Douglas fir Karamatsu, Hiba, Hinoki, Port Onford cedar Tsuga, Western hemlock, Momi, Ezomatsu, Todomatsu, Benimatsu, Sugi, Western red cedar, Spruce Standard strength requirements Kashi 12.0 Kuri, Nara, Buna, Keyaki Table 3. Average of apparent density and Young s modulus by longitudinal vibration method in each group Test group of bending strength, compressive strength parallel to the grain, shear strength parallel to the grain and compressive strength perpendicular to the grain 523 (6.82) 10.3 (15.3) 521 (6.46) 10.3 (15.2) Test group of tensile strength parallel to the grain ρ: Density, : Young s modulus by longitudinal vibration method. Value in the parentheses is coefficient of variance. 9 3, 2010

7 Strength of yellow cypress lumber - Bending strength, compressive strength parallel to the grain, tensile strength parallel to the grain, shear strength parallel to the grain, and compressive strength perpendicular to the grain Table 4. Test results on bending strength Apparent E b True E b σ bp σ b JAS II JAS visual grading (in loading span) JAS II JAS visual grading (in full length) Bulletin of FFPRI, Vol.9, No.3, 2010

8 132 IDO. H et al Table 4. Test results on bending strength (cont.) Apparent E b True E b σ bp σ b JAS II JAS visual grading (in loading span) JAS II JAS visual grading (in full length) , 2010

9 Strength of yellow cypress lumber - Bending strength, compressive strength parallel to the grain, tensile strength parallel to the grain, shear strength parallel to the grain, and compressive strength perpendicular to the grain Table 4. Test results on bending strength (cont.) Apparent E b True E b σ bp σ b JAS II JAS visual grading (in loading span) JAS II JAS visual grading (in full length) TP No Mean CV Min Max Moisture content, Density, Young's modulus by longitudinal vibration method, E b Bending Young's modulus, σ bp Bending stress at the proportional limit, σ b Bending strength, JAS Japanese agricultural standards for sawn lumber, CV Coefficient of variance Bulletin of FFPRI, Vol.9, No.3, 2010

10 134 IDO. H et al Table 5. Test results on compressive strength parallel to the grain E c σ cp σ c E c σ cp σ c , 2010

11 Strength of yellow cypress lumber - Bending strength, compressive strength parallel to the grain, tensile strength parallel to the grain, shear strength parallel to the grain, and compressive strength perpendicular to the grain Table 5. Test results on compressive strength parallel to the grain (cont.) E c σ cp σ c TP No Mean CV Min Max Moisture content, ρ Density, Young's modulus by longitudinal vibration method, E c Compressive Young's modulus, σ cp Compressive stress at the proportional limit, σ c Compressive strength parallel to the grain, CV Coefficient of variance Bulletin of FFPRI, Vol.9, No.3, 2010

12 136 IDO. H et al Table 6. Test results on tensile strength parallel to the grain E t σ tp σ t JAS II JAS visual grading (between the grips) , 2010

13 Strength of yellow cypress lumber - Bending strength, compressive strength parallel to the grain, tensile strength parallel to the grain, shear strength parallel to the grain, and compressive strength perpendicular to the grain Table 6. ( ) Test results on tensile strength parallel to the grain (cont.) E t σ tp σ t JAS II JAS visual grading (between the grips) Bulletin of FFPRI, Vol.9, No.3, 2010

14 138 IDO. H et al Table 6. ( ) Test results on tensile strength parallel to the grain (cont.) E t σ tp σ t JAS II JAS visual grading (between the grips) TP No Mean CV Min Max Moisture content, ρ Density, Young's modulus by longitudinal vibration method, E t Tensile Young's modulus, σ tp Tensile stress at the proportional limit, σ t Tensile strength parallel to the grain, JAS Japanese agricultural standards for sawn lumber, CV Coefficient of variance 9 3, 2010

15 Strength of yellow cypress lumber - Bending strength, compressive strength parallel to the grain, tensile strength parallel to the grain, shear strength parallel to the grain, and compressive strength perpendicular to the grain Table 7. Test results on shear strength parallel to the grain σ s σ s TP No Mean CV Min Max Moisture content, ρ Density, σ s Shear strength parallel to thegrain, CV Coefficient of variance σ s Bulletin of FFPRI, Vol.9, No.3, 2010

16 140 IDO. H et al Table 8. Test results on compressive strength perpendicular to the grain 5% σ cv-5% f c,90 f c,90,y K c,90 (N/mm 3 ) , 2010

17 Strength of yellow cypress lumber - Bending strength, compressive strength parallel to the grain, tensile strength parallel to the grain, shear strength parallel to the grain, and compressive strength perpendicular to the grain Table 8. Test results on compressive strength perpendicular to the grain (cont.) 5% σ cv-5% f c,90 f c,90,y K c,90 (N/mm 3 ) Bulletin of FFPRI, Vol.9, No.3, 2010

18 142 IDO. H et al Table 8. Test results on compressive strength perpendicular to the grain (cont.) 5% σ cv-5% f c,90 f c,90,y K c,90 (N/mm 3 ) TP No Mean CV Min Max Moisture content, ρ Density, Young's modulus by longitudinal vibration method, σ CV-5% 5% Compressive stress perpendicular to the grain at 5% deflection, f c,90 : Compressive strength perpendicular to the grain, f c,90,y : Yeild strength of compression perpendicular to the grain, K c,90 : Stiffness of compression perpendicular to the grain, CV Coefficient of variance 9 3, 2010

19 Strength of yellow cypress lumber - Bending strength, compressive strength parallel to the grain, tensile strength parallel to the grain, shear strength parallel to the grain, and compressive strength perpendicular to the grain Table 9. Summary of test results on bending strengh Apparent E b True E b σ b 5% TP No Mean CV Min Max Moisture content, ρ Density, Young's modulus by longitudinal vibration method, E b Bending Young's modulus, σ b Bending strength, CV Coefficient of variance Bulletin of FFPRI, Vol.9, No.3, 2010

20 144 IDO. H et al Table 10. Test results on bending strength by visual grading according to Japanese agricultural standards for sawn lumber II 1 For bending member II 1st grade Apparent E b σ b 5% TP No Mean CV Min Max II 2 For bending member II 2nd grade Apparent E b σ b 5% TP No Mean CV Min Max II 3 For bending member II 3rd grade Apparent E b σ b 5% TP No Mean CV Min Max II For bending member II out of grade Apparent E b σ b 5% TP No Mean CV Min Max Moisture content, ρ Density, Young's modulus by longitudinal vibration method, E b Bending Young's modulus, σ b Bending strength, CV Coefficient of variance 9 3, 2010

21 Strength of yellow cypress lumber - Bending strength, compressive strength parallel to the grain, tensile strength parallel to the grain, shear strength parallel to the grain, and compressive strength perpendicular to the grain Table 11. Summary of test results on compressive strength parallel to the grain E c σ c 5% TP No Mean CV Min Max Moisture content, ρ Density, Young's modulus by longitudinal vibration method, E c Compressive Young's modulus, σ c Compressive strength parallel to the grain, CV Coefficient of variance Table 12. Summary of test results on tensile strength parallel to the grain E t σ t 5% TP No Mean CV Min Max Moisture content, ρ Density, Young's modulus by longitudinal vibration method, E t Tensile Young's modulus, σ t Tensile strength parallel to the grain, CV Coefficient of variance Bulletin of FFPRI, Vol.9, No.3, 2010

22 146 IDO. H et al Table 13. Test results on tensile strength parallel to the grain by visual grading according to Japanese agricultural standards for sawn lumber II 1 For bending member II 1st grade Apparent E t σ t 5% TP No Mean CV Min Max II 2 For bending member II 2nd grade Apparent E t σ t 5% TP No Mean CV Min Max II 3 For bending member II 3rd grade Apparent E t σ t 5% TP No Mean CV Min Max II For bending member II out of grade Apparent E t σ t 5% TP No Mean CV Min Max Moisture content, ρ Density, Young's modulus by longitudinal vibration method, E t Tensile Young's modulus, σ t Tensile strength parallel to the grain, CV Coefficient of variance 9 3, 2010

23 Strength of yellow cypress lumber - Bending strength, compressive strength parallel to the grain, tensile strength parallel to the grain, shear strength parallel to the grain, and compressive strength perpendicular to the grain Table 14. Summary of test results on shear strength parallel to the grain σ s 5% TP No Mean CV Min Max Moisture content, ρ Density, σ s Shear strength parallel to the grain, CV Coefficient of variance Table 15. Comparison with other species using the full-scale block shear test σ s Species Mean ρ Mean 5% CV Standard strength requirements Douglas fir Hinoki Western hemlock Yellow cypress Sugi ρ Density, σ s Shear strength parallel to the grain, CV Coefficient of variance Bulletin of FFPRI, Vol.9, No.3, 2010

24 148 IDO. H et al Table 16. Summary of test results on compressive strength perpendicular to the grain 5% σ cv-5% 5% 試験体数 TP No 平均値 Mean 変動係数 CV 最小値 Min 最大値 Max : 含水率 Moisture content, ρ: 密度 Density, : 縦振動法のヤング係数 Young's modulus by longitudinal vibration method, σ CV-5% :5% 変形時の応力 Compressive stress perpendicular to the grain at 5% deflection, CV: 変動係数 Coefficient of variance Table 17. ISO Comparison with other species by ISO test method Species TP number Mean ρ Mean f c,90 5% CV Standard strength requirements Karamatsu Hiba Yellow cypress Sugi Western hemlock ρ Density, f c,90 : Compressive strength perpendicular to the grain, CV Coefficient of variance 9 3, 2010

2 800 lb/in 2 5,000 12,000 lb/in 2 1/ lb/in lb/in lb/in a, b 1989, 1990a 102 Table AWCOM 1977a, b, c, d, e, f, g AWCOM

2 800 lb/in 2 5,000 12,000 lb/in 2 1/ lb/in lb/in lb/in a, b 1989, 1990a 102 Table AWCOM 1977a, b, c, d, e, f, g AWCOM (Bulletin of FFPRI) Vol.17 No.1 (No.445) 1-33 March 2018 1 総説 (Review article) 我が国の製材規格と許容応力度の変遷 1 1. f b f c f t f s f cv F b F c F t F s F cv 23 1948 f b f c f t f s f cv kg/cm 2 kgf/cm 2 2. 39 12 1906