Jurnal f the Krean Ceramic Sciety Vl. 44, N. 9, pp. 502~509, 2007. Examinatin n Applicatin f High-Perfrmance Cncrete using Fine Fly Ash as Replacement Material f Silica Fume Bum-Sik Lee, Sang-Kyu Kim, Sang-Yun Kim, Sun-Mi Chi, and Gun-Su Lee Husing & Urban Research Institute, Krea Natinal Husing Crp., Sengnam 46-704, Krea (Received August 18, 2007; Accepted September 12, 2007) š gj p e { š v m Á½ ³ Á½ Á Á w kœ k (2007 8 18 ; 2007 9 12 ) ABSTRACT This paper investigated hw Fine Fly Ash (FFA) with 14,000 cm 2 /g f Fineness affects the micr structure and material prperties f High-Perfrmance Cncrete (HPC) befre and after hardening frm Material Test f HPC and Cement Paste. FFA is applied as a substitute f Silica Fume which is used necessarily in prducing HPC. As a Material Test results, 5% FFA series specimen shws the lwer fluidity than SF series specimen. When, hwever, the Fluidity f 10% FFA series specimen is increased reversely t the similar value f SF series specimen. The Prsity f FFA series specimen f day age is displayed t 21~24%, which is higher than 19~20% prsity f SF series specimen, while that f day age is reached t 8~ 9%, which is imprved cmpared with 10% f SF series specimen. It can be thught that FFA has better influence n the prsity f HPC in case f lng term age. The Cmpressive strength f FFA series specimen shws the similar result with the prperty f prsity. The cmpressive strength f day age FFA series specimen is 98~ 106% f SF series specimen and 107% f plain specimen t reveal better strength develpment. Key wrds : High-Perfrmance Cncrete, Fine Fly Ash, Silica Fume, Prsity 1. 19» gj pƒ z g j p t ƒ,» gj p wš w» z» k š gj p w šd, x p y š. šd š š gj p w w yy ƒ š g j p j» w e { v š. ù e { yy w šƒ yy š gj p w œ ƒ, š gj p w wš š gj p z Crrespnding authr : Sang-Kyu Kim E-mail : skkim@jugng.c.kr Tel : +82-1-78-4688 Fax : +82-1-78-4612 w w q. š gj p v wš šƒ e { w yy, y wš w y ey gj p ƒ» v ƒœw š v ( 14,000 cm 2 /g) w. š š gj p e { š v y v w» œw» w š v sww w [ p, FA(, š ), BS] w r p gj p w š v ƒ š gj p y z e w sƒw. 2. x z 2.1. x z š gj p š e { š v sƒ w» w š v ƒ ƒ 5%, 10% 502
š gj p e { š v m 50 Table 1. Design f Experiment Mix plan (wt %) Factr Levels * OPC BS FA SF FFA W/B(%) OPC-100 100 - - - - Plain 60 25 15 - - SF-5 55 25 15 5 - Admixture SF-10 50 25 15 10-2.5 FFA-5 55 25 15-5 FFA-10 50 25 15-10 õ BS:blastfurnaceslag, FA:Flyash, SF:Silicafume, FFA:Fineflyash (blaine 14,000 cm 2 /g) Cncrete Cement paste Testing items Air cntents Fluidity(Slump-flw) Cmpressive strength Hydratin materials(xrd) Hydratin degree(dt-tga) Prsity structure(mip) Micr structure(sem) Micr hydratin heat(tcc) Table 2. The Chemical Cmpnent f Materials (wt %) Blaine (cm 2 /g) SiO 2 Al 2 O Fe 2 O CaO MgO SO Na 2 O K 2 O TiO 2 Ig.lss OPC,44 21.6 5.2.6 62.78 2.7 2.4-0.8-0.90 BS 4,400 4.8 17.5 0.6 42.4.1 0.0 - - - 0.02 FA,400 59.5 25.4 5.8.7 0.7-0.4 1.1 1.6 1.60 SF 200,000 98.5 0. 0.1 0.5 0.1 0.1 0.1 - - 0.70 FFA 14,000 5.1 17.4 16.0 6.4 0.8 0.2 0.2 1.5-6.46 x z w, e { 5%, 10% w x OPC x (OPC, BS, FA) x z w ƒƒ w r p gj p x w x ww. š v ƒ š gj p e w sƒw» w r p x w œ y sƒw, š gj p x w v y z sƒw. zw š gj p 80 MPa( t 96 MPa), x z d w Table 1. 2.2. x p š ü S, v K q š w. e { ü š Fig. 1. SEM f raw materials. w eù w, e { w š v 14,000 (Blaine, cm /g) š ü W 2 w w. k w š x w v w y w. ƒ yy yw Table 2. Fig. 1 SEM w e {, v, š v x w, š v e { x w e,» OPCù š x w ƒ ù š, v š x û w e. x w, 19 mm w w. š AE ü W š w t w. 2.. x d 2..1. x e { š v sƒw» w š gj p y z w sƒ p r p w sƒƒ w. w Table 1 x z w x, gj p œ w. š š v 44«9y(2007)
504 Á½ ³Á½ Á Á e { š gj p y e w sƒw» w v w yp w» w p r p x w. ƒ x d ¾ z d w, x w x ww d w. 2..2. d 1) gj p ƒ yy y» s ƒwš, š v ƒ swwš k w yy mw» w x ww. x w z v v x š w w 1 z y d w. 2) š gj p d KS F 2405 gj p w ww. ) y y w x w gj p w e, ³ wù š v e { š gj p e w w» w y d w. y mw» w w 50% Cnductin calrimeter 7 w y d w. 4) y w ƒ ùkù y x y w» w XRD 5~65 d w š, y Ca(OH) 2 ( w CH w) C-S-H y w DT-TGA 10 C/min 25~1000 C¾ d w, y w» w SEM Fig. 2. Fluidity f fresh cncrete. ww. 5) œ e { w š gj p š w y s w œ œ ƒ, e { š v w w œ w» w pr p œ 1 1 1cm j» w y z (Mercury Intrusin Prsimetry, MIP) w d w. x 10~60,000 psi.2 nm l 50 µm œ œ j» s w.. x š.1. gj p p v w w k w yy w w. š v gj p e w» w w z 1 z y w Fig. 2. Fig. 2 e { w x w š v w x v v ƒ wš, v v ƒ 50 cm w ƒw ù, v v ƒ 55 ±5cm ƒ j š š v 10% w ùkû. š v w v ƒ jš v k šƒ 1) w z ƒ k w d š v e { ƒ w..2. p r p yp.2.1. y p m yy w z 7 y y y ƒƒ Table Fig. ùkü. 7 ¾ y OPC w ƒ ùkùš, y Plain>SF-5> FFA-10>FFA-5>SF-10 ùkùš. y e { w e { w» z ƒ yw y š š, e { w š v 10% w w wz
š gj p e { š v m 505 Table. Ttal Hydratin Heat fr 7 Day Specimen OPC Plain SF5 SF10 FFA5 FFA10 Hydratin heat 11 257 240 214 221 26 (J/g) Fig.. Hydratin heat accrding t time. vjƒ ùkû. s³,» y 4) j, 2,) Y. Halse v 1 vj w š w, x š v 10% w w w w..2.2. y, w XRD Fig. 4 ùküš. 10 z p ƒ p r p vj» d w»ƒ. OPC100 x w e { w CH w ù š v w CH w ùkû. ù š v w CH w e {» w e, š v z w w e q. w w 1 ƒƒ d SEM. Fig. 5 1 x SEM w w, p» p ƒ pƒ j e w, x š œ p ƒ pƒ w e w. OPC w w p ƒ p C-S-H š, e{ w C-S-Hƒ ù š v w y š y. š v w x. ù š v w 1 CH C-S-H y. w š v w 1 ¾ j z ¾ š w w 1 z C-S-H z ùkû. w š v 10% w OPC 100% x w x w C-S-H š, XRD 11 z y w š v y w s w w SiO 2 CH w C-S-H. Fig. 4. XRD patterns accrding t the age. 44«9y(2007)
이범식 김상규 김상연 최선미 이건수 506 Fig. 5. Fig. 6은 SEM images accrding t the age. 재령 일에 결합재에 따른 DT-TGA 측정결 과를 그래프로 나타낸 것이고, Table 4는 TGA측정에 의 한 온도에 따른 질량 감량율을 나타낸 것이다. 일반적으 로 알려진 수화물들의 온도에 의한 변화는 C-S-H계 수화 물은 100~10 C에서 탈수, 에트링가이트는 100 C 이하 및 100 C, 160~180 C에서 최대피크를 보이며, 250~270 C에서 작은 피크를 보이며 단계적으로 탈수한 다. 또한 모노설페이트는 50~150 C 및 200~00 C에서 세단계로 탈수하고, CH는 400~500 C에서 물과 CaO로 분 해된다고 보고되고 있다. Fig. 6에 의하면 100 C 전후와 170 C 근처의 피크는 에 트링가이트와 모노설페이트의 탈수에 의한 것이라 사료 되며 이 피크는 고분말 플라이애시를 사용한 경우 가장 5) Fig. 6. DT-TGA curve at the day curing. 한국세라믹학회지 크게 나타나고 있고, 이를 통해 고분말 플라이애시는 초 기의 모노설페이트 및 CAH상 생성에 영향을 미친다고 사료된다. 또한 450 C 전후에서의 흡열 피크는 CH의 피크로 재 령 일에 OPC가 가장 크고, Plain, 실리카흄, 고분말 플 라이애시 순으로 나타났다. 이러한 경향은 TGA곡선을 보 아도 동일하게 나타나며, 감량을 정량화 해본 결과 OPC >Plain>SF-5>FFA-10>FFA-5>SF10의 순으로 나타났다. OPC만을 사용한 경우는 재령 일에 최종 CH생성량이 14.9%로 나타났고, 실리카흄 10%의 경우 5.5%, 고분말 Results f Gravimetric Thermal Analysis f Cement Pastes after, Days Curing Cmpsitin f blend Weight lss (%) 400-480- Ca(OH)2 age 100(wt %) (day) 420C 480 C 1000C wt (%) 5.6 2.6 1.7 10.5 OPC 8.4.6 2.1 14.9 5.9 1.9 2.8 7.9 Plain 8.4 2.0 1.8 8. 5.8 1.6 1.7 6.5 5 10.6 2.2 2.0 9.2 SF 5.8 1.4 2.2 5.6 10 6.6 1. 2.0 5.5 5.8 1.7.2 7.0 5 8.0 1.7 1.8 6.9 FFA 5.5 1.6.1 6.7 10 8.9 1.8.0 7.2 Table 4.
š gj p e { š v m 507 Table 5. Results f Prsimetry f Cement Pastes after, Days Curing Cmpsitin f blend Plain SF FFA (wt %) 5 10 5 10 age (day) Prsity (%) Ttal pre Median pre vl (ml/g) Diameter (nm) 19.8 0.098 9.8 10.4 0.0494 4.5 19.5 0.1011. 9.9 0.0488 4.4 19.2 0.1072 19. 10.2 0.0500 4.5 21. 0.1115 29.1 9.0 0.04 4.4 2.1 0.1227 29.5 8.1 0.091 4.2 Fig. 7. Prsity f cement paste accrding t the age. Fig. 8. The distributin curve f pre size. v 10% 7.2% ùkû. w OPC w yy w ƒ p w s Fig. 9. Pre size distributin f cement paste. w w... œ Table 5 prsimeter d w œ, œ, s³ œ w ùkü š, Figs. 7~9 Table 5 ùkù vyw ùkü. gj p œ ùkü œ œ, œ s, Fig. 7 œ r» Plain w e { w w w œ ùkü, š v yww ƒ ƒ œ ùkü š v» z w. ù» š v ƒ œ œ w SEM š v z z w. Fig. 8 œ s ùkü» OPC 100% x ƒ ƒ û ùk ü ù, œ j» wš š v w x ƒ œ ƒ ùkù. Fig. 9 w w» 10 ~ 50 nm œ s, 5nm w œ œ j»ƒ. w w OPC w s yy yww. s ƒ SiO 2ƒ p y CH yww ³ e (CaO SiO 2 nh 2 O) g y w jš,» y 44«9y(2007)
508 Á½ ³Á½ Á Á Fig. 10. Cmpressive strength f cncrete. Fig. 11. Relatinship f cmpressive strength with prsity. w z ùkü. w OPC w w x j œ š 10 nm w œ w j» w. Fig. 10 ƒ w Plain w w.» e { š v w ƒ wš ù 7 5% ƒ Plain w w ùkü,» Plain w zw, ƒw w ùkû. x t 80 MPa w e{ w 5%, š v w ƒ j 100 MPa w ùkû. Fig. 11 w s ƒ w œ yƒ e w» w œ v txw. œ w ƒ š, œ w ƒw. s ƒ z s w CH e f p y y w œ, œ» q. 4. š v e { š gj p w» w» w» w w x mw w. 1. š v w š w wƒ w ù, š v ƒ ƒw ƒ w ùkû. 2. XRD SEM mw y, š v» wù z e{ w ùk ü.. œ, OPC w x w y y w ƒ ùkû. e { w w š v w û œ ùkü. w yy w» œ ƒ y ùk û. w w w ƒ š, š v w ƒ œ w ƒ xw ùkû. 4. e { 5% w yp w e ùkû ù, š v 10% w 5% w p ùkü e { w š g j p x d ƒ w. Acknwlengement m 05 w» ( y :05 w D11) w w š g j p w šd œ k Ì ¾. REFERENCES 1. K. Ogawa, Uchikawa, and K. Takemt, The Mechanism w wz
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