J. of Korean Institute of Fire Sci. & Eng. [ ] Vol. 23, No. 2, 2009 w w w w w w Stud on the Fire Behaviour of Composite Beam with Loading and Unloading ½ *Á û**á½ ***Á½ Sung-Bae Kim* Chang-Nam Lee** Woo-Chul Kim*** Sang-Seup Kim *( ), **( ), ***( ) xf e», w» w œw (2008. 8. 26. / 2009. 4. 16. k) üv ew TSC w w w w w w x, ew k w ü sƒ w. üv 3 ü eƒ 40mm ù 25mm e z ü x w. w t e w w. x TSC w 25mm üv ew w w x 3 ü w ùkû. w w w ü» w, s³ 250 o C w, š 310 o C wƒ. w x k w w. ABSTRACT In this stud, the fire resistance performance of a simple support composite beam, which was spraed with fire protection coatings, was evaluated. Primar valuables of the stud are loading and unloading, shape of composite beam and metal lath of the web. The thickness of the fire protection coating to the three hour resistance is 40mm, but the fire resistance test was performed with 25mm coatings. The test result showed that TSC composit beams with 25mm fire protection coatings can resist on fire for three hours at the both loading and unloading tests. Average and maximum temperatures were less than 250 o C and 310 o C respectivel, compared with the standard temperatures for fire resistance on the loading and unloading tests. Kewords : TSC composite beam, Fire resistance, Loading and unloading, Fire protection coating 1. ƒ w w wš. w» gj p ww w j l v e p œ, gj p w wš. p gj p 1,2) w w w x š. w gj p w» E-mail: kimss@kut.ac.kr 27 gj p w w q. p w ü w gj p w z gj p ü ü w». ù w ü sƒ», x w w w, p w sƒ, üv w. 3-6) üv ew TSC w w w w w x, ew k w ü s ƒ w, t e w w.
28 ½ Á ûá½ Á½ Table 1. Specimen Parameters No. Name Shape Load Lath 1 T4-U-1 TSC IV unloading exclude 2 T2-U-1 TSC II unloading include 3 T2-U-2 TSC II unloading include 4 T4-L-1 TSC IV loading exclude 5 T2-L-1 TSC II loading include 6 H-L-1 H Shape loading exclude 2. x z 2.1 x z x w w x x k Á, w w Á zw. T2-U» x x w xw. x Table 1, 6 x w. x x Figure 1 v p( v ) ( ), w v p( w v ) TSC w, v ƒ Á ù x x TSC II, v ƒ s x TSC IV wš, Hx sww. w w w w w w ƒ w sƒw š, ww x w ü w 2.3 w. d KS F 4552 k (ss 1) 1/2 j ew s v w k d š g. k TSC II x w, TSC IV Hx ew. üv, 25mm e z 3 ü x ww. x v 3 w 40mm Ì w» l ü t. Table 2 üv w. x Figure 1, Figure 2 ¼ ƒ 5.0m š, s 600mm, Ì 150mm sww 550mm. TSC 400 270 6( s Ì, mm) Figure 1. Cross section of specimen (unit: mm). š, Hx ü e H-400 200 8 13(mm) w. 7) t r p z üv sw, üv w w mw. x gj p 27MPa(f ck = 270kgf/cm 2 ) š, w (σ ) Table 2. Weight Mix Proportion of Fire Resisting Material Classfication Vermiculite Cememnt Gpsum Calcium Carbonate Additive Weight Ratio (%) 30 24 23 6 17
w w w w w w 29 Figure 2. Plan view of test set up. Table 3. Material Properties of Concrete Slump (cm) W/C (%) S/a (%) Cement Unit Weight (kg/m 3 ) 18 47.0 47.0 347 Table 4. Material Properties of Steel σ (MPa) σ u (MPa) Elongation (%) TSC II 311 459 25 TSC IV 295 458 27 Figure 3. Detail of thermocouple. 235MPa(SS400, F = 2,400kgf/cm 2 ), w 400MPa(f = 4,000kgf/cm 2 ). gj p p (Mill sheets) w, ƒƒ Table 3, Table 4. 2.2 x w w x t d w Figure 3 w. ƒ ü s 4m 1/4, 2/4, 3/4 e ƒƒ 4 t ew š, KS C 1615 KS C 1602 0.75 ƒ Kx. e 3z g e e ew w. 7) sƒ w q» w x, KS F 2257-1 w x x (D = L /400d) x x 2 (dd/dt = L /9000d) 2 q w, L/30 w w. w x d w s³ ƒ 538 o C(1,000 o F), 649 o C(1,200 F) o w. x w q» w x x. 8) D = L 2 ----------- = 400d 4, 200 2 ---------------------- = 80.2 ( mm) 400 550 Figure 4. Photo of test set up. dd L 2 4, 200 2 ------ = ---------------- = dt 9, 000d 9 ---------------------------, 000 550 = 3.56 ( mm/min ) L ----- = 4 -------------, 000 = 140 ( mm) 30 30 ƒ x t š w ƒ x ww, x q ƒ Figure 2, Figure 4. ƒ w 4 ƒ w š, w d w. 2.3 ww ww ü x (KS F J. of Korean Institute of Fire Sci. & Eng., Vol. 23, No. 2, 2009
30 ½ Á ûá½ Á½ Ágj p : Á ----- = 475mm t c = 40 + 15 2 Figure 5. Detail of shape. 2257-1) w xw ³ ³ ƒ w w wš. x 2003 x 8) w w w š,» w w w ww w. w x 9) Figure 1 TSC» w,»t Figure 5. 1) Á (SS400) w : F = 235MPa Ágj p : f ck = 27MPa Á l f l : φ16 @200 ÁTSC w (400 270 6) : ÁA f = 980mm 2 ÁA w = 4,608mm 2 ÁA p = 2,220mm 2 ÁA s = 7,808mm 2 t f = 393mm t w =198mm t p =13mm t s = 169.9mm ÁTSC w (400 270 6) 2 p: ÁI s = 1.64 10 8 mm 4 2) w Ágj p k : ÁE c = 4,700 = 24,422N/mm 2 Á k : E s = 206,000N/mm 2 Ák : f ck n = E s ---- = 8.44 E c Ágj p ƒ : Ágj p ƒ 2 p: I Á--- c = b 3 e t ------------ s = 2.0 10 7 mm 4 n 12n Á : Á t f + A w t A ----- c = 10, 664mm 2 n = A f w + A p ------------------------------------------------------------------ t p = 169.9mm t s A f + A w + A p Áw : Á = A s t s + A c /n t 0 A s + A c /n Á 2 p: ÁI tr = I s + A s =6.04 10 8 (mm 4 ) Áw d : ÁS te = I tr ----- = 1.75 10 6 mm 3 Áw d : ÁS ce = I tr I ----- = tr 3) ww (P = 162kN ƒ ) ww (4)w { m gj p w mw. Á š w Ágj p : 4.66kN/m ÁTSC : 0.60kN/m Áš w : Á(4.66 + 0.60) 4.2 = 22.1kN Á p : ÁM max (= M D +M L ) = 1.3P = 239kNÁm 4) { m { m ew ew w, x TSC š z gj p k w e w. { ew mw. Á m: Áf b = M + M D L ---------------------- F b Á t --------------------------------------------- c = 346.0mm t o t 0 S te ( t 0 t s ) 2 + I c --- + A c -----( t c t 0 ) 2 n n -------------------------- = 2.96 10 6 mm 3 H + t s t 0 239 106 f b = ---------------------- = 136.6 ( N / m m 2 ) F b 1.75 10 6 ÁF b = 0.66F = 155.1(N/mm 2 ) O.K Ágj p m: Áf bc = M + M D L ---------------------- F bc ns ce
Á 239 10 6 f bc = -------------------------------------- = 9.57( tf/cm 2 ) F bc 8.44 2.96 10 6 ÁF bc = 0.4F ck = 10.8(N/mm 2 ) O.K 5) ww ƒ w w (P = 162kN) w gj p x ü ww Figure 2 2P w, 2P = 2 162 = 324kN(= 33tf) x ww w. ww TSC II TSC IV ƒ w TSC w w w ƒ w. w Hx w ƒ e z w š w ww 265kN(= 27tf) w. 2.4 x œ t w k» z w, k» w t w»». t KS M 6030 1 w w Ÿ wr p w, v z, ( v ) ww. 10) w» ü w x t w z e s w x ww. ù x k š q w ü x w w sƒw. 1) t w.»w w w ( ) (Anode reaction) ƒ w e ( ) (Cathod reaction) ww. w (1)~ (3) tx. (Fe(OH) 2 :, ) (4) w (Fe(OH) 3 ) š, e w γ-fe 2 O 3 -nh 2 O( k: k)ƒ. 11) e w w t 2~6µm Ì k(passivit)v v (γ-fe 2 O 3 -nh 2 O) x l w. e üv e (Ca(OH) 2 ) w ph w w w w w w 31 12.0~13.5 w e k. 12) t e üv v w t k v w w. Fe Fe 2+ +2e ( ) (1) 1/2O 2 +H 2 O+2e 2OH (e ) (2) Fe + 1/2O 2 +H 2 O Fe(OH) 2 ( ) Fe(OH) 2 +1/2H 2 O + 1/4O 2 Fe(OH) 3 ( k ) (3) (4) 2) œ»á Á k w, wš w ƒ w. m (Pb 3 O 4 ) ƒ w. 3) x x w ³ KS F 2902 w w, (5) w w. q ü ƒ w q (cohesive strength) k ü e q (adhesive strength). B=F/A B: (N/mm 2 ), F: (N) A: mx (mm 2 ) Figure 6. Photo of adhesion test set up. (5) J. of Korean Institute of Fire Sci. & Eng., Vol. 23, No. 2, 2009
32 ½ Á ûá½ Á½ x 300 300(mm) w j» q k, k»» k q w 3 w. q ü v e z 1 w w (83mm) x e s w g. s ƒ z x»(utm) w ü e v q d w, ƒ 10mm/min. Figure 6 x. l k, k»» k. 3. x š 3.1 x Table 5 x. x q k» e 363 10 4 (N/mm 2 ). ù k ù k» Table 5. Relation of Adhesion Strength and Finish States of Steel Plate ( 10 4 N/mm 2 ) Corrosion Steel Protected Corrosion Paint Bared Steel 1st 570 480 590 2nd 580 490 570 3rd 580 480 590 Average 577 483 583» k q (bared steel) w 15~20% w. q e üv» ¼ w x ƒ,» 6 ƒ» 1 w. 11,13) t e z 1 w» sƒ wì» š w w. x e ü v k» j w ùkû. 3.2 x Table 6 w w w w x. ü q» w v x s³ š wù, w x x ü sƒw. ù Table 6 w x x, x wì»w, s³ ƒ A, B, C (Figure 3 ) š w. x TSC w w 25mm ü v ew w w x 3 (180 ) ü w ùkû.» s³ š ƒƒ 20 w ùküš. p x x k Á, w Á w w. ù Hx ü 112,» w 105 Table 6. Summar of Test Results Name Allowable Average Temperature or Deflection over Time Time (min) Temperature/Deflection (mm) Allowable Max. Temperature or Strain Rate over Time Time (min) Temperature/Strain Rate (mm/min) Fire Resistance Time (min) T4-U-1 180 237.3 180 308.6 180 T2-U-1 180 242.2 180 298.1 180 T2-U-2 180 250.1 180 306.6 180 T4-L-1 180 T2-L-1 180 H-L-1 244.2 301.2 180 10.2 0.2 237.4 287.4 180 10.0 0.7 106 590.9 105 649.8 112 90.2 109 4.2 180 180 112
하중재하 영향에 의한 합성보의 화재거동에 관한 연구 Figure 7. T2-U-1 specimen before test. Figure 8. T2-U-1 specimen after test. Figure 9. 33 Temperature development against time of unloading specimen. Figure Figure 10. 11. specimen. H-L-1 specimen after test. TSC 합성보에 비해 상당히 저하되었다. Figure 7~Figure 9는 TSC 합성보와 H형강 보의 시 험 전 후의 모습이다. H형강 실험체의 경우 하부 플 랜지의 피복재가 휨변형에 의해 탈락되어 급격한 온도 상승과 함께 내력이 저하되었으며, 단부가 크게 변형 되었다. 반면 TSC 보 실험체는 재하 및 비재하 실험 Mid span deflection against time of loading 모두 실험 종료 후에도 내화피복재의 탈락이 발생되지 않았다. 각 실험체의 실험진행 양상을 육안 관찰한 결 과 수증기 발생 및 상부 슬래브 수분발생, 마구리면의 수분 분출 순으로 수증기 및 수분이 관찰되었으나, 분 출 시점은 각 실험체 마다 상이하였다. Figure 10은 비재하 실험체의 온도와 시간 그래프이 며, Figure 11은 재하실험체의 변형과 시간 그래프이다. 비재하 실험체의 경우 최고온도와 평균온도 모두 실험 체의 종류 및 형상에 따른 차이를 보이지 않고 있다. 또한 재하 실험체의 경우 변형과 시간 그래프는 H형 강의 경우 큰 차이를 보이고 있으나, TSC 보 실험체 는 형상과 메탈라스 부착에 의한 영향은 없는 것으로 나타났다. 3.3 위치별 온도분포 Table 7은 비재하 실험체의 각 단면에 부착한 열전 대의 온도분포를 실험이 종료한 시점(180분 경과)으로 정리한 것이다. 열전대 부착번호는 Figure 3과 같이 A J. of Korean Institute of Fire Sci. & Eng., Vol. 23, No. 2, 2009
34 ½ Á ûá½ Á½ Table 7. Summar of Thermocouple of Unloading Specimen (at 180minute) Specimen T4-U-1 T2-U-1 T2-U-2 Thermocouple No. ( o C) 1 2 3 4 5 6 7 8 9 10 11 12 251.1 211.3 256.2 150.0 308.6 249.3 252.9 138.3 295.1 238.8 251.3 138.6 297.3 243.0 243.5 185.1 298.1 243.5 238.5 177.7 288.0 246.4 246.4 145.7 304.3 279.5 257.7 159.0 306.6 259.3 241.8 158.5 301.5 239.1 243.3 168.4 l 1~4, B 5~8, C 9~12. ƒ ü w KS ³ w š š, w w. d e(1~4, 5~8, 9~12 ƒ e) w, w v ƒ. w d e(a, B, C ) w ƒ w ùküš. e s» 100~150 o C š ù, d e 10 o C ƒ j. e w, 1 2 ( 5 6, 9 10 ) w v ù, 1Á5Á9 2Á6Á10 50 C o w. w w 2Á6Á10 ƒ e 1Á5Á9 w gj p w ƒ w» q. TSC w ƒ Hx w š ƒ û gj p w w. 3.4 x w Figure 12 x w w w k e Á ƒ x s³ š w. w w w sƒ wù» š. w Figure 12. Relation of load-temperature and lath-temperature. k e Á w w» j ƒ k Á w š q. d k ü v e w e w w ü w w ew ù, x û w. w ƒ m mw w v ƒ š q. x x w Table 6, Figure 12 mw, v x w xá x, Hx x Á x j š. w TSC H x TSC ü gj pƒ k gj p š jš, gj p ü ƒ w j z {w» q. 4. w (TSC w ) w w w k e w, x ü x ww x. 1. TSC w 25mm üv ew w w x 3 ü w ùkû. w w w ü» w, s³ 250 o C w, š 310 o C wƒ. w TSC, x k Á w w 5% ü ùkû.
2. d e ù, e w ƒ j ùkû. e w w v ƒ ƒ š w, w v w v 50 o C w. w w v ƒ w gj p w ƒ w» q, w TSC w ƒ Hx w š ƒ û gj p w w. 3. q k k,, k»» k w x q k» e 363 10 4 (N/mm 2 ). ù w kù k»» k q (bared steel) w 15~20% w. š x 1., Ÿ, Ÿ, ½, e œ w itech beam { sƒ, w wz Vol.18, No.4, pp.67-74(2002). 2.», e, z, ½ w,, w, e dš x w œ Process œ, w k wz, Vol.7, 6(2007). w w w w w w 35 3. w z,, ½, e Hx w v ü w, w w z, Vol.19, No.4, pp.235-246(2006). 4., ½, TSC w p w x - w w ü w, w wz, Vol.24, No.1, pp.27-35(2008). 5. ½, w z,, Hx w w x, w wz, Vol.22, No.2, pp.84-90(2008). 6. Deric J. Oehlers and Mark A. Bradford, Elementar Behaviour of Composite Steel and Concrete Structural Members, Butterworth-Heinemann(1999). 7. m š 2005-122, ü e - ü t x (2005). 8. w t xz, KS F 2257 - ü x (2005). 9. w wz, (2004). 10. w wz, m œ t» (2006). 11. ³,»w w gj p sƒ (2006. 12). 12. zœ z, gj p ü e w (2005. 6). 13., eüv w x. J. of Korean Institute of Fire Sci. & Eng., Vol. 23, No. 2, 2009