本研究探討使用國產材種以及進口材種，以5層5單片製成之直交集成板（Cross-Laminated Timber, CLT）樓板於火害後的承載能力行為，並利用數值模擬分析軟體SAP2000進行建模，藉由實驗結果並驗證模型的可行性。國產材種為國產柳杉CLT樓板，並使用未火害的對照組，透過實際的實驗數據分析火害前後的力學行為。另外，進口材種分別是日本柳杉+日本扁柏CLT樓板(中間三層為日本柳杉)以及歐洲赤松CLT樓板，來探討國外常見材種火害後的強度性能。
首先，將組裝完成之樓板進行1小時防火加載試驗，隨後切割並量測其炭化深度及殘餘斷面。再利用四點載重試驗測試各試體之抗彎強度和抗彎彈性模數，以規範制定強度基準作為參考及比對，並將實驗結果繪製出力與位移曲線。此外，藉由等值EI的計算得出殘餘斷面的有效彎曲剛度和實驗值進行探討，並驗證其適用性，最後與未火害的斷面強度進行比較。實驗結果顯示，火害後的強度會因拼接、膠合劑的使用及製造過程中有無側拼而產生影響。在國產柳杉CLT樓板的對照組發現，除了斷面減少會影響整體強度與勁度外，溫度也會導致強度的衰減，並使得材料的彈性模數降低約0.9倍。至於日本柳杉+日本扁柏與歐洲赤松製成的CLT樓板，由於使用較薄的斷面尺寸(12 cm)且板片間無側拼，使得火容易從縫隙間竄出，導致斷面燃燒得較快，進而影響了殘餘斷面的強度，整體CLT樓板結構的勁度受損。
本研究以驗證方式利用四點載重試驗之實驗值與SAP2000數值模擬分析方式進行位移結果的探討，並使用等向性和異向性模型來進行分析。結果顯示，未火害斷面使用等向性和異向性分析時，誤差控制於5%以內；火害後斷面進行數值模擬分析時，誤差均在10%以內，且在異向性分析時發現，若需更保守估計火害後斷面時，則需考量材料斷面受到溫度的影響。而本研究也證實兩種模擬分析方式之可行性。

This study investigates the load-bearing capacity of 5-layer Cross-Laminated Timber (CLT) floors after fire damage, using SAP2000 for modeling and validation through experimental results. It examines domestically produced Taiwan Cedar CLT floors and imported Japanese Cedar + Japanese Hinoki and Scots Pine CLT floors to assess post-fire strength properties of commonly used wood species.
After a one-hour fire test on the CLT floors, char depth and residual cross-section are measured. A four-point bending test then evaluates bending strength and modulus of elasticity, compared to standard strength criteria. Effective bending stiffness of the residual cross-section is calculated using equivalent EI, and results are compared with experimental values and the un-heated cross-section's strength. The study finds that post-fire strength is influenced by joints, adhesive use, and edge gluing. In Taiwanese cypress CLT floors, cross-section reduction and temperature decrease strength and reduce the modulus of elasticity by about 0.9 times. For Japanese Cedar + Japanese Hinoki and Scots Pine CLT floors, thinner cross-sections and lack of edge gluing cause faster burning and weaken the residual cross-section strength and overall stiffness.
Using experimental values and SAP2000 numerical simulation analysis, the study investigates displacement with isotropic and orthotropic models. Results show that isotropic and orthotropic analysis errors for un-heated cross-sections are within 5%, and for post-heated cross-sections within 10%. However, in the orthotropic analysis, it was found that considering the temperature effects on the cross-section after fire damage resulted in analysis outcomes that were closer to the experimental values. This study confirms the feasibility of both simulation methods.

[1] M. F. Laguarda Mallo and O. Espinoza, “Awareness, perceptions and willingness to adopt Cross-Laminated Timber by the architecture community in the United States,” Journal of Cleaner Production, vol. 94, pp. 198-210, 2015.
[2] R. Brandner, G. Flatscher, A. Ringhofer, G. Schickhofer, and A. Thiel, “Cross laminated timber (CLT): overview and development,” European Journal of Wood and Wood Products, vol. 74, no. 3, pp. 331-351, 2016.
[3] F. Wiesner, R. Hadden, S. Deeny, and L. Bisby, "Structural fire engineering considerations for cross-laminated timber walls," Construction and Building Materials, vol. 323, 2022.
[4] CLT Handbook (USA Edition), FPInnovations, 2013。
[5] 經濟部標準檢驗局，「中華民國國家標準CNS 16114直交集成板」，2019。
[6] European Committee for Standardization (CEN), “EN 16351.Timber structures—Cross laminated timber—Requirements”, 2021.
[7] American National Standards Institute (ANSI) and APA—The Engineered Wood Association, “ANSI/APA PRG 320.Standard for Performance-Rated Cross-Laminated Timber”, 2019.
[8] A. Ceccotti, C. Sandhaas, M. Okabe, M. Yasumura, C. Minowa, and N. Kawai, “SOFIE project – 3D shaking table test on a seven‐storey full‐scale cross‐laminated timber building,” Earthquake Engineering & Structural Dynamics, vol. 42, no. 13, pp. 2003-2021, 2013.
[9] X. Zhao, B. Zhang, T. Kilpatrick, and I. Sanderson, “Numerical Analysis on Global Serviceability Behaviours of Tall CLT Buildings to the Eurocodes and UK National Annexes,” Buildings, vol. 11, no. 3, 2021.
[10] R. Cherry, A. Manalo, W. Karunasena, and G. Stringer, “Out-of-grade sawn pine: A state-of-the-art review on challenges and new opportunities in cross laminated timber (CLT),” Construction and Building Materials, vol. 211, pp. 858-868, 2019.
[11] Q. Zhou, M. Gong, Y. H. Chui, and M. Mohammad, "Measurement of rolling shear modulus and strength of cross laminated timber fabricated with black spruce," Construction and Building Materials, vol. 64, pp. 379-386, 2014.
[12] P. Fellmoser and H. J. Blaß, "Influence of rolling shear modulus on strength and stiffness of structural bonded timber elements," in CIB-W18 meeting, 2004, vol. 37.
[13] P. Mestek, H. Kreuzinger, and S. Winter, "Design of cross laminated timber (CLT)," in 10th world conference on timber engineering, 2008, pp. 156-163.
[14] C. O’Ceallaigh, K. Sikora, and A. Harte, “The Influence of Panel Lay-Up on the Characteristic Bending and Rolling Shear Strength of CLT,” Buildings, vol. 8, no. 9, 2018.
[15] D. P. Hindman and J. C. Bouldin, “Mechanical Properties of Southern Pine Cross-Laminated Timber,” Journal of Materials in Civil Engineering, vol. 27, no. 9, 2015.
[16] 林志憲，「國產材於直交集成板之製造及其工程性能評估」，國立中興大學森林學研究所博士論文，臺中市，2020。
[17] R. Stöd, J. Marttila, L. Tomppo, A. Haapala, and E. Verkasalo, “Modulus of Elasticity and Bending Strength of Scots Pine (Pinus sylvestris L.) Wood from Commercial Thinnings,” Forests, vol. 15, no. 3, 2024.
[18] A. S. Yusoh, M. K. A. Uyup, P. Md Tahir, L. Seng Hua, and O. C. Beng, “Mechanical performance and failure characteristics of cross laminated timber (CLT) manufactured from tropical hardwoods species,” Physical Sciences Reviews, vol. 9, no. 1, pp. 85-94, 2024.
[19] S. Pradhan, M. Mohammadabadi, E. D. Entsminger, and K. Ragon, “Influence of densification on structural performance and failure mode of cross-laminated timber under bending load,” BioResources, vol. 19, no. 2, pp. 2342-2352, 2024.
[20] H. Li, L. Wang, Y. Wei, B. J. Wang, and H. Jin, “Bending and shear performance of cross-laminated timber and glued-laminated timber beams: A comparative investigation,” Journal of Building Engineering, vol. 45, 2022.
[21] H. Li, B. J. Wang, L. Wang, and Y. Wei, “An experimental and modeling study on apparent bending moduli of cross-laminated bamboo and timber (CLBT) in orthogonal strength directions,” Case Studies in Construction Materials, vol. 16, 2022.
[22] European Committee for Standardization (CEN), “EN 1995-1-2.Eurocode 5: Design of Timber Structures—Part 1-2: General—Structural Fire Design”, 2004.
[23] M. Fragiacomo, A. Menis, I. Clemente, G. Bochicchio, and A. Ceccotti, “Fire Resistance of Cross-Laminated Timber Panels Loaded Out of Plane,” Journal of Structural Engineering, vol. 139, no. 12, 2013.
[24] A.H.Buchanan, “Structural design for fire safety,” Wiley,Chichester, UK, 2002.
[25] D. Hopkin et al., "Large-Scale Enclosure Fire Experiments Adopting CLT Slabs with Different Types of Polyurethane Adhesives: Genesis and Preliminary Findings," Fire, vol. 5, no. 2, 2022.
[26] I. M. Okuni and T. E. Bradford, "Modelling of Elevated Temperature Performance of Adhesives Used in Cross Laminated Timber: An Application of ANSYS Mechanical 2020 R1 Structural Analysis Software," presented at the The 1st International Electronic Conference on Forests—Forests for a Better Future: Sustainability, Innovation, Interdisciplinarity, 2020.
[27] L. Muszyński, R. Gupta, S. h. Hong, N. Osborn, and B. Pickett, "Fire resistance of unprotected cross-laminated timber (CLT) floor assemblies produced in the USA," Fire Safety Journal, vol. 107, pp. 126-136, 2019.
[28] F. Wiesner, R. Hadden, S. Deeny, and L. Bisby, "Structural fire engineering considerations for cross-laminated timber walls," Construction and Building Materials, vol. 323, 2022.
[29] SAP2000, “CSI Analysis Reference Manual,” Computers and Structures, Inc., USA, 2017.
[30] 侯政伯、廖硃岑，「直交集成板斷面性質之數值模擬分析」，建築學報，(125)，1-14，2023。
[31] M. He, X. Sun, and Z. Li, “Bending and compressive properties of cross-laminated timber (CLT) panels made from Canadian hemlock,” Construction and Building Materials, vol. 185, pp. 175-183, 2018.
[32] M. He, X. Sun, Z. Li, and W. Feng, “Bending, shear, and compressive properties of three- and five-layer cross-laminated timber fabricated with black spruce,” Journal of Wood Science, vol. 66, no. 1, 2020.
[33] X. Li, M. Ashraf, M. Subhani, P. Kremer, B. Kafle, and K. Ghabraie, “Experimental and numerical study on bending properties of heterogeneous lamella layups in cross laminated timber using Australian Radiata Pine,” Construction and Building Materials, vol. 247, 2020.
[34] P. Dobeš, A. Lokaj, and K. Vavrušová, “Stiffness and Deformation Analysis of Cross-Laminated Timber (CLT) Panels Made of Nordic Spruce Based on Experimental Testing, Analytical Calculation and Numerical Modeling,” Buildings, vol. 13, no. 1, 2023.
[35] 汪姮慈，「直交集成板(CLT)之炭化速率及火害後抗彎強度研究」，國立臺灣科技大學建築研究所碩士論文，臺北市，2021。
[36] Japanese Agriculture Standards (JAS), “JAS 3079.Cross Laminated Timber,” Ministry of Agriculture, Forestry and Fishers, Tokyo, 2019.
[37] 經濟部標準檢驗局，「中華民國國家標準CNS 12514-5/A3305-5 建築物構造構件耐火試驗法-第5部：承重水平區劃構件特定要求」，2014。
[38] 中華民國內政部營建署，「建築技術規則-建築構造編」，2020年11月。
[39] 中華民國內政部營建署，「木構造建築物設計及施工技術規範-構材設計」，2021年1月。
[40] Y. Wang, J. Zhang, F. Mei, J. Liao, and W. Li, "Experimental and numerical analysis on fire behaviour of loaded cross-laminated timber panels," Advances in Structural Engineering, vol. 23, no. 1, pp. 22-36, 2020.
[41] S. Krzosek, M. Grześkiewicz, I. B. Kupniewska, P. Mańkowski, and M. Wieruszewski, “Mechanical Properties of Polish-Grown Pinus Sylvestris L. Structural Sawn Timber from the Butt, Middle and Top Logs,” Wood Research, vol. 66, no. 2, pp. 231-242, 2021.
[42] 王寶芬，「CLT牆版於既有鋼筋混凝土建築物耐震補強之可行性分析研究」，國立成功大學土木工程研究所碩士論文，臺南市，2022。
[43] 李佳如、林志憲、蔡明哲，「評估臺灣三種針葉木材製造直交集成板之燃燒性質」，國立臺灣大學生物資源暨農學院實驗林研究報告，38(1)，1-16，2024。
[44] S. Ukyo, A. Miyatake, K. Shindo, and Y. Hiramatsu, "Shear strength properties of hybrid (hinoki cypress and Japanese cedar) cross-laminated timber," Journal of Wood Science, vol. 67, no. 1, 2021.