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1 No e pude motrar la imagen vinculada. Puede que e haya movido, cambiado de nombre Comparion of the fire reitance of two tructural wall ytem in Light Steel Framing Fabricio Bolina, Roberto Chrit, Andrea Metzler, Uziel Quinino & Bernardo Tutikian Facultad de Ingeniería, Univeridade do Vale do Rio do Sino, São Leopoldo, Brail. andreametzler@hotmail.com, fabriciolb@uniino.br, rchrit@uniino.br, uquinino@uniino.br, bftutikian@uniino.br Received: June 08 th, Received in revied form: December 13 th, Accepted: January 30 th, Abtract The technological development of civil contruction ector ha led to the exploration of indutrialized building ytem. One of thi ytem i the tructural Light Steel Framing (LSF), which conit in cold formed teel frame juxtapoed with drywall encloure of different material, uch a cement board, wood board and platerboard. Depite of the advantage of thi ytem, there i till a concern about their fire afety. Therefore, thi paper aimed to verify the fire reitance of LSF ytem with two type of platerboard, one compoed of tandard platerboard (common) and the other one by fire-reitant platerboard. The ample were teted according to the [1]. It wa evaluated integrity, thermal inulation and tructural tability of each olution. The reult preented the ytem with fire-reitant platerboard more ecure when compared to the tandard platerboard (common). In both cae, the ample failure occurred due to the lo of integrity in the panel' joint. Keyword: Fire reitance; light teel frame; fire-reitant platerboard. Comparación de la reitencia al fuego de do itema de parede etructurale en Light Steel Framing Reumen El dearrollo de la contrucción civil ha llevado a itema de contrucción indutrializado. Uno de eto e el Light Steel Framing (LSF), marco de acero conformado en frío yuxtapueto con cerramiento de panele de tablero de cemento, madera o placa de yeo. Todavía hay una preocupación acerca de u eguridad contra incendio. Ete etudio objetivó verificar la reitencia al fuego de lo itema de LSF con do tipo de placa de yeo, uno compueto por placa etándar y el otro con yeo reitente al fuego. La muetra fueron analizada a travé de la curva de fuego [1]. Durante la prueba, e evaluó la integridad, ailamiento térmico y etabilidad etructural de cada olución. Lo reultado preentaron el itema con placa de yeo reitente al fuego má eguro que la placa de yeo etándar. En ambo cao, el fracao fue debido a la pérdida de integridad de la articulacione de lo panele. Palabra clave: Reitencia al fuego; light teel frame; placa de yeo reitente al fuego. 1. Introduction The growth of contruction market in indutrialized countrie ha increaed the ue of innovative contruction ytem into reidential building. Building with reduced cot and more efficient contruction proce i a real need in the indutry. In order to fulfill thi purpoe the ector i heading indutrial procee [2]. However, the performance of thee alternative mut be analyzed and teted to evaluate it ue a a building ytem [3,4], ince it ue i growing in the world [2]. Every ytem mut meet the minimum performance requirement for it ue, uch a thoe precribed by the tandard [5,6]. The [5] and [6] have a mainly qualitative approach and it i baed on the minimum requirement of (a) utainability, (b) houing and (c) afety of the building and it ytem How to cite: Bolina, F., Chrit, R., Metzler, A., Quinino, U., and Tutikian, B., Comparion of the fire reitance of two tructural wall ytem in light teel framing. DYNA 84(201), pp , The author; licenee Univeridad Nacional de Colombia. DYNA 84(201), pp , June, Medellín. ISSN Printed, ISSN Online DOI:

2 [4,7]. Among the afety requirement there i the fire reitance of tructural ytem. In the event of a fire, a tructural ytem hould not compromie the evacuation of uer, nor the integrity of the urrounding building and the work of recue team [8]. The minimum fire reitance time of thee ytem i a function of time, occupation and ue of the building. However, the Light Steel Framing (LSF) ytem preent a hort reitance period of time when expoed to a fire ituation [9]. In ome cae, thee ytem do not meet the minimum afety condition [10]. LSF i one of the tructural ytem not pecified by fire deign tandard. It i a building ytem tructured with cold haped galvanized teel frame coated with treated board, which together form partition ytem able to withtand the deign action. Depending on the lenderne of thee frame, thee ytem may have a tructural function. Since it i an indutrialized and dry contruction ytem, the LSF ha great execution peed and material rationalization [3], and promote a foundation relief due to it low total weight. On the other hand, there i till a gap on teting and employability reearch tudie, depite of the increae in it ue in the market [11]. It wa noted that there i till heitation about it actual performance a building ytem [12], a their behavior in a fire ituation and it effective applicability in thi condition [11]. Recognized a a lightweight contruction ytem, it i characterized by it low fire reitance, which can be improved by the ue of pecial material. The behavior of thi type of ytem i connected to everal parameter, epecially on it configuration and/or type of panel, geometric apect and the load rate applied [13], which make harder to undertand their actual behavior in a fire ituation. The deduction of thi et of factor emphaize the need of carrying out fire reitance experimental tudie and the knowledge of their behavior during a fire [11]. The fire reitance evaluation of a tructural wall ytem i tandardized by the [14-17]. Thee tandard generally tate that three condition mut be meet: (a) integrity, (b) thermal inulation, and (c) tructural tability. During the tet, the furnace hall conform to a tandardized rie of e, uch a [1]. Thi curve i a well-accepted imulation of the fire curve in a building to carry out thi type of analyi, ince a real fire curve i influenced by everal factor, uch a fuel load, ventilated area, etc. [18] In order to determine the performance of tructural LSF ytem in a fire ituation, thi paper aimed to analyze and compare two tructural wall of thi ytem, both with the ame thickne and layering, but with different type of platerboard: tandard (common) board and the known a fire-reitant board. Following the tandard precription, the wall have been teted in full cale, with dimenion of 315x300cm expoed to the action of high e from a tandardized and calibrated vertical furnace, which conform to the e curve defined by [1]. The tudy wa divided into four tage: (1t) introduction; (2nd) experimental ; (3rd) reult and dicuion; and (4th) concluion. 2. Experimental Fig. 1 preent the layer that compoe the tudied ytem. Figure 1. Sytem layer characterization. The material ued in the compoition of ample are following detailed Material Steel frame The cold haped metal frame (tened C hape) have height of 90mm and width of 40mm with thickne of 12mm, produced with galvanized teel. The teel ha a yield tre of 600MPa. The teel frame received a urface treatment of zinc and aluminum, which enure a high corroion reitance Wood particleboar The wood particleboard are tructural panel of oriented trand board (OSB) wood type compriing thin trip and oriented perpendicularly to each other in everal layer, which increae it rigidity and trength. Thee trip are attached with a rein applied under high e and preure, phenolic type. The board have thicknee of 11.1mm and denity kg/m³ Cement board The cement board are ued to protect the wall ytem ( area of the building) and are made from a mixture baed on cement and ynthetic fiber. The board have thicknee of 10.0mm and denity of 1.20g/cm³ Platerboard The platerboard have a denity of 1.45g/cm², are noncombutible and have flexural trength of 9MPa. Two type of platerboard were ued. The board named Standard, which i ideal to ue only in dry environment i made of natural gypum. The other board, named fire reitant", i produced from natural gypum with the addition of natural fiber and admixture to improve it reitance to fire. 124

3 Gla wool The gla wool i ued for a better thermal and acoutic inulation and ha a thermal reitance of 1.52m². C/W, denity 40.00kg/m³ and a thickne of 50.0mm Specimen The ample have 315cm of width, 300cm of height and 13.5cm of thickne. The teel frame ued in the aembly of thi ytem were paced every 60cm, with a thickne of 90.0mm. The arrangement of the frame wa choen according to the ultimate bending moment reitance of the internal wall ytem (plater and wood board), auming a afety factor of 1.4. The ample labeled "A" i a wall with OSB compoite board, 11.1mm thick, applied both internally and ly. Thi board ha a bracing tructural function of the board. The platerboard ued wa the tandard type, with 12.5mm thick, applied over the OSB board. In the urface, alo on the OSB board, a cement board with thickne of 10mm wa intalled. Sample "B" wa compoed of the ame material than ample A, except the platerboard, which wa the fire reitant type, 12.5mm thick. Table 1 give a breakdown of the contituent layer of thee ample. Fig. 2 how the tep of mounting and the appearance of the finihed ample. Fig. 2a tand out the intallation of the teel frame (rigid frame), Fig. 2b detail OSB board application on halfway up to the platerboard, and Fig. 2c i the finihed ample coupled to the vertical furnace. Figure 2. Sample-mounting equence: (a) board with teel frame, (b) ytem encloure (c) ample coupled to the furnace Table 2. Lit of the equioment ued in tet Decription Model Calibration Vertical furnace Thermographic camera Laer tape GFT FG A325 GLM 80 Profeional Reolution 0,01 ºC Thermal capacity 1200º FLIR Boch 2.3. Vertical furnace The vertical furnace i heated by four liquefied petroleum ga burner, controlled by differential preure a the examined area. The burner are intalled at the furnace idewall (two per wall) and are calibrated to increae the e according to the curve etablihed by [1] The e development i monitored during the tet by two thermocouple intalled inide the furnace. In the event of a deviation, a correction of the flame intenity produced i performed automatically. The e of ample Table 1. Detail of tet ample Sample Cutting Compoition A - Cement board 10mm; - Steel fram 90x40x12mm; - Gla wool 50mm; - Standard (ST) platerboard 12.5mm B - Cement board 10mm; - Steel fram 90x40x12mm; - Gla wool 50mm; - Fire-reitant (RF) platerboard 12.5mm Figure 3. Numbering of internal thermocouple Figure 4. Numbering of thermocouple urface i meaured by five thermocouple, alo intalled within the furnace. The e of ample expoed urface i the of the e meaured by thermocouple arranged ymmetrically on the furnace inner region, in number equal to five, with one for each 1.5m² of expoed urface. Temperature are meaured with an accuracy of ±1.5% Intrumentation Table 2 preent the equipment ued during the tet. The internal (face of the ample expoed to fire) and thermocouple (face of the ample not expoed to fire) are type K with diameter of 4 mm and 2 mm, repectively. Fig. 3 and Fig. 4 illutrate the poition of the thermocouple. 125

4 2.5. Evaluation criteria For the analyi of both ytem, it wa evaluated the parameter of integrity, thermal inulation and tructural tability, a defined [14-17] to check the fire reitance of tructural wall. The analyi of the thermal inulation i made by the thermocouple meaurement in the urface not expoed to fire of the ample. In order to be thermal inulated, the maximum rie of e mut be le or equal to 180 C in each thermocouple or 140 C on the of all the thermocouple, whichever occur firt, adding the initial e of the trial [14,16,17]. The crack found in the ample during the tet are not allowed to releae hot gae through it opening. The integrity i verified with a dry cotton wool pad poitioned on the crack for 10 econd, which can not inflame during the expoure, a define [14-16]. Crack that have not caued the inflammation of cotton wool pad were diregarded in thi tudy, a it doe not compromie the integrity parameter. To ait the identification of the crack during the tet, a thermographic camera wa ued on the urface not expoed to fire. The tructural tability wa verified by the horizontal deformation developed during the tet, which wa meaured uing a laer tape pointed to the center of the not expoed urface. The ytem wa ubjected to the action of a uniformly ditributed load of 15kN/m, imulating a lab action load. According [14], the fire reitance time of the ample correpond to 80% of the time period in which the element wa charged and ubjected to the tet. Regarding the overall deformation of the load-bearing wall ytem, the tandard tate that it can not be exceive, admitting a maximum deformation of 1/30 of the pan. 3. Reult and dicuion 3.1. Thermal inulation The e recorded in the ample "A" and Sample "B" are preented in Fig. 5 and Fig. 6, repectively. Manifetation occurring during the tet are preented Table 3. Figure 6. Specimen B urface e Fire Reitant (FR) platerboard. The ambient e at the tet beginning wa 24.5 C and in turn the tet limit i C for the e of five thermocouple and C for each thermocouple (thermal inulation). The ample A tet lated 51.5 minute, wherea the ample B lated 62.0 minute when the tet were finihed. However, the e of the five thermocouple ha not reached C in both cae, or any individual thermocouple e reached C. Therefore, the ample with fire reitant platerboard had tet duration 10.5 minute, or 20.3%, higher than the ample with tandard platerboard. According to the picture and e graph preented on Table 3, the ample had a imilar behavior up to 40 minute of tet. The wall uing the tandard platerboard (ample A ) had initially a heat concentration at the joint, being later ditributed throughout the ytem urface. The ame occurred with the ample with fire reitant platerboard (ample 'B'), which, however, preented a better performance for 10.5 minute when compared to ample A. In both cae, it wa noted that the metal bolt are the firt element to preent an abrupt. It wa evident that it protection, or ubtitution by inulating material, can contribute to the thermal inulation of wall ytem uing platerboard. The bolt and joint might be conidered a weak point of thi kind of ytem Integrity Figure 5. Specimen A urface e Standard (ST) platerboard. After 45 minute from the beginning of the tet, it wa noticed a vertical crack between two cement board () on ample A (Fig. 7). At the ame moment, the cotton wool pad tet wa performed. With the crack propagation, the tet wa repeated at 51.5 minute and, at thi occaion, the hot gae expelled caued the cotton wool pad inflammation, characterizing the ytem lo of integrity. In the tet of ample B, vertical crack were identified between board (at the joint) 50.0 minute after the beginning of the tet (Fig. 8). However, trhough the cotton wool pad tet the ample till maintain it integrity. After 62 minute of teting, the action of the hot gae produced by thi opening ha paed to compromie ytem integrity and the tet wa finihed. 126

5 Table 3. Temperature evolution at the unexpoed picemen urface Sample A Sample B 0 minute Comment 0 minute Comment The tart with e of the urface at 24.5 C. The tart with e of the urface at 24.5 C. 15 minute Comment 15 minute Comment Highlighte d the bolt. Note the e on the center-left area of the ample. Marked of the bolt, with remarkable e rie in the joint between board. 30 minute Comment 30 minute Comment External e i 33.8 C and the maximum regitered i 38.5 C External temp. i 30.1 C. There i a heat in the upper region of the ample. 45 minute Comment 45 minute Comment internal furnace temp. i C and the temp. of ti 50.0 C. The temp. i 37.4 C. Heat ditribution ample urface. 51,5 minute Comment 62 minute Comment End of the due the cracking followed by detachmen t between board, lo of integrity. End of the due the cracking followed by detachment between board, lo of integrity. Note that the joint have proved to be the weaket point of the ytem, independently from the type of platerboard ued. For thi reaon, it i emphaized the importance of Figure 7. Lo of integrity moment of (a) ample A and (b) ample B. Figure 8. Deformation veru time. enuring the fire reitance propertie in all component of the ytem, not only at the platerboard, a well a it joint Structural tability Fig. 8 preent the evolution of meaured deformation during both tet. Since the expoed pan length wa mm, the deformation limit i 83.3mm. For both ample, the deformation wa very imilar up to 30.0 minute of tet and le than 10.0mm. From the 30.0 minute, ample A preented higher total deformation, leading to a lo tructural tability. However, the deformation did not compromie the ue of both ample, even though ample A reached 80.0mm at 50.0 minute of teting. 4. Concluion It wa concluded that the ample with fire-reitant platerboard type preented a better fire performance when compared to the tandard platerboard type for all the analyzed parameter: thermal inulation, integrity and tructural tability. The ample with fire-reitant platerboard had tet duration of 10.5 minute longer than 127

6 the tandard type, or 20.3% higher than the ample with tandard platerboard, preenting the efficiency of uing thi type of material. From the 30.0 minute, ample A preented higher total deformation, probably due to the higher increae of e on the urface, leading to a lo tructural tability. After 45 minute from the beginning of the tet, it wa noticed a vertical crack between two cement board on ample A, intead ample B, 50 minute. In both cae, the joint between panel and bolt were critical in their behavior during the fire expoure, being reponible for the lo of integrity due the paage of gae. Therefore, attention hould be taken to the thermal protection of thee element in order to promote a greater fire afety of tructural LSF ytem. Reference [1] International Organization for Standardization (ISO). ISO 834-1: Firereitance tet - Element of building contruction - Part 1: General requirement Genebra, [2] Veljkovic, M. and Johanon, B., Light teel framing for reidential building. Thin-Walled Structure, 44(12), pp , DOI: /j.tw [3] Lorenzi, L.S., Análie crítica e propoiçõe de avanço na metodologia de enaio experimentai de deempenho à luz da ABNT NBR (2013) para edificaçõe habitacionai de interee ocial térrea. [.l.] Univeridade Federal do Rio Grande do Sul, [4] Okamoto, P.S. e Melhado, S.B., A norma braileira de deempenho e o proceo de projeto de empreendimento reidenciai. Maceió: XV ENTAC, 2014 [5] ABNT. Aociação Braileira de Norma Técnica. NBR : Edificaçõe Habitacionai Deempenho. Rio de Janeiro, [6] International Organization for Standardization (ISO). ISO 6241: Performance tandard in building - Principle for their preparation and factor to be conidered. Genebra, [7] Sorgatto, M.J. et al., Análie do procedimento de imulação da NBR para avaliação do deempenho térmico de edificaçõe reidenciai. Ambiente Contruido, 14(4), pp , [8] Guo, Q. et al., Probabilitic evaluation of tructural fire reitance. Fire Technology, 49(3), pp , DOI: / [9] Gunalan, S. and Mahendran, M., Finite element modelling of load bearing cold-formed teel wall ytem under fire condition. Engineering Structure, 56, pp , DOI: /j.engtruct [10] Kodur, V.K.R. and Sultan, M.A., Factor influencing fire reitance of load-bearing teel tud wall. Fire Technology, 42(1), pp. 5-26, 2006 DOI: / y [11] Alfawakhiri, F. Sultan, M.A. and Mackinnon, D.H., Fire reitance of loadbearing teel-tud wall protected with gypum board: A review, Fire Technology, 35(49, pp , DOI: /A: [12] Gome, A.P., de Souza, H.A. and Tribe, A., Impact of thermal bridging on the performance of building uing Light Steel Framing in Brazil. Applied Thermal Engineering, 52(1), pp , DOI: /j.applthermaleng [13] Gunalan, S. and Mahendran, M., Development of improved fire deign rule for cold-formed teel wall ytem. Journal of Contructional Steel Reearch, 88, pp , DOI: /j.jcr [14] ABNT. Aociação Braileira de Norma Técnica. NBR. 5628: Componente contrutivo Determinação da reitência ao fogo. Rio de Janeiro, [15] Japanee Standard Aociation (JIS). JIS A 1304: Method of fire reitance tet for trucutral part of building. Tóquio, [16] Standard Aociation of Autralia. AS : Method for fire tet to building material, component and tructure. Camberra, [17] Britih Standard. BS 476. Fire tet on building material and tructure. London, [18] Cadorin, J.F., Comportment fire model for tructural engineering. They. Univerité de Liége. Liége, F. Bolina, received the MSc. degree in 2016 from Uniino, Brazil. He i a profeor of teel tructure at Uniino, Civil Eng. Dept. Hi reearch interet include: performance of tructure in fire. ORCID: X R. Chrit, received the BSc. in Civil Engineering in 2011 and MSc. degree in Engeneering in 2014, all of them from the Uniino, Brazil. He i a profeor of tructure and material at Uniino, Civil Engineering Dept. Hi reearch interet include: performance of building material. ORCID: A. Metzler, received the BSc. in Civil Engineering in 2015 from Uniino, Brazil. ORCID: U. Quinino, received the BSc. Eng. in Civil Engineering in 2001 from UFPB, the MSc. degree (2004) and the PhD degree in Structural Engeneering (2015) from the UFRGS, Brazil. He i a profeor of tructure at Uniino Hi reearch interet include: fiber reinforced concrete and tructure analyi. ORCID: B. Tutikian, received the BSc. Eng in Civil Engineering in 2002, MSc. degree in 2004 and the PhD degree in Civil Engineering in 2007, all of them from UFRGS, Brazil. He i a profeor at Uniino, hi reearch interet include: concrete technology and performance of building material. ORCID: Área Curricular de Ingeniería Civil Oferta de Pogrado Epecialización en Vía y Tranporte Epecialización en Etructura Maetría en Ingeniería - Infraetructura y Sitema de Tranporte Maetría en Ingeniería Geotecnia Doctorado en Ingeniería - Ingeniería Civil Mayor información: aiacic_med@unal.edu.co Teléfono: (57-4)