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1 Journal of the Korean Ceramic Society Vol. 45, No. 6, pp. 336~344, Rheological Properties of Cement Paste Blended Blast Furnace Slag or Fly Ash Powder Jong Taek Song, Hyo Sang Park, Seung Ho Byun, and Dong Woo Yoo Department of Materials Science and Engineering, Dankook University, Cheonan , Korea (Received April 26, 2008; Accepted June 13, 2008) š v yww p r p p k Á z Á yá w œw ( ; ) ABSTRACT Rheological properties of cement pastes containing blast furnace slag (BFS: 3,900, 7,910 cm 2 /g) or fly ash powder (FA: 4,120, 8,100 cm 2 /g) according to the ratio of water/binder (W/B) and the dosage of polycarboxylate type superplasticizer (PC) were investigated by a mini slump and a coaxial cylinder viscometer. In this experiment, the ratio of replacing OPC with BFS or FA was 30 wt%, the W/B was from 30 to 70 wt%. As a result, the fluidity of cement paste containing BFS or FA was improved with increasing W/B and the dosage of PC. BFS or FA replaced cement paste with W/B 70% and PC 0.3% showed the highest fluidity. The segregation range of cement paste was occurred below 10 d/cm 2 of the yield stress and below 50 cps of the plastic viscosity by the coaxial cylinder viscometer. And also it was formed that the plastic viscosity and the yield stress of FA replaced cement paste were higher than them of BFS replaced cement paste. Key words : Fly ash, Blast furnace slag, Rheological properties, Yield stress, Plastic viscosity 1. šd ƒ gj p št y, ü w š. gj p t w w gj p yw ey ƒ yw w ƒ y w š. p yw 1-6), yw yw w gj p yw gj p j ù. t gj p yw 7) š, v, e v, ke w y š. w š y k z w s v ey» w, ƒƒ s w gj p» ü w» w. 2) p yw w, p y w, š v m sp Corresponding author : Jong-Taek Song Song8253@dankook.ac.kr Tel : Fax : d y, CO 2 y w j w š š. gj p yw ƒw p r p p š y yw ey y p 7-9) š ù š w v Ÿ p w w w., š v (4,120, 8,100 cm /g)w w ( w W/B 2 w) s e p š y (šx 20%) ƒ y p v z d mw š w. 2. x 2.1. x p S m sp p ( w OPC w) w, yw S š ( w BFS w) w. v ( w FA w) s y w. Blaine BFS 3,900, 7910 cm 2 /g ( w S1, S2 š w), FA 4,120, 8,100 cm 2 /g ( w F1, F2 š 336

2 Table 1. Chemical Compositions of Raw Materials BFS FA š v yww p r p p 337 Average Partical Al 2 O 3 SiO 2 Fe 2 O 3 CaO MgO TiO 2 K 2 O Na 2 O SO 3 Ig.loss Blaine (cm 2 /g) Size (µm) OPC ,350 S ,900 S ,910 F ,120 F ,100 (wt%) w) w w, OPC BFS, FA yw Table 1 ùkü. š y ü L s e p š y ( w PC w) w. x w Table 2 ùkü, BFS FA W/B y PC ƒ p r p v z d mw p w v x d v x» w p r p w W/B PC ƒ w d w. x 10) v x k p r p p w yw z w» w š x. w w v g v g š v v w y ùküš 11) p. x w v g p r p 1 ew z, v g r p r ù ƒ 4 w s ³ w t w. w, 90 ¾ y d w d 1 w. x p r pù gj p d w» w» x w sƒ v v x(ks F 2402) ù v x yw» w x š, y w Table 2. Experimental Factors Leverls Factors W/B 30, 50, 70 (wt%) Admixtures BFS (S1, S2), FA (F1, F2) Replacement Ratio of Mineral Admixtures 30 (wt%) Dosages of PC 0, 0.3, 0.5 (wt%) (plastic viscosity) w (yield stress) ƒ š. 2) Table 2 w r p 3 z mx» š v 1rpm 150 rpm z w w d w. x rpm w ùkù (Shear Stress) mw (Plastic Viscosity) w (Yield Stress) w.» š r p ³ew ùkü» ƒ w w 150/sec 30/sec w l xz w»»ƒ r p ƒ. w l l d š w š (0/sec) ù r r p w ƒ. 12) x z Brookfield RVDV II+(USA), spindle SC4-29 w. w r p yw ey 30 wt% W/B 30%, 50%, 70%, PC 0%, 0.3%, 0.5% ƒw x ww. 3. x š 3.1. p r p BFS FA yww p r p W/B y PC w v Fig. 1, 2 ùkü. PC ƒ W/Bƒ ƒw š, w W/B PC w FA BFSƒ ùkü. d S1>S2, F2>F1, S1>S2>F2>F1 ùkû. W/B 30%, PC ƒ S1 S2, F1 F2 W/B 30% PC ƒ ƒw v d w. BFSƒ w» š q, t š w ñ š w xk. w BFS s³ p p œ ƒ» 45«6y(2008)

3 338 ká z Á yá Fig. 1. Change of Mini Slump with time in cement pastes. (a) W/B : 30% S1, F1 (b) W/B : 50% S1,F1 (c) W/B : 70% S1, F1 (d) W/ B : 30% S2, F2 (e) W/B : 50% S2, F2 (f) W/B : 70% S2, F2. ( : Segregation) w wz

4 고로슬래그 및 플라이 애시 분말을 혼합한 시멘트 페이스트의 유동특성 Fig Change of Mini Slump as a function of PC dosage in cement pastes. (a) PC 0% (b) PC 0.3% (c) PC 0.5% ( : Segregation) 동성에 관여하는 자유수가 증가하여 FA보다 높은 유동성 을 나타낸 것으로 판단된다. FA는 미분화된 물질로 입형 이 구형이고, 표면이 매끄러운 입자여서 유동성이 우수하 지만 미소량 함유된 미연소탄소량에 의해 BFS보다는 유 동성이 감소된 것 이라 생각된다. BFS와 FA의 입형사 13,14) Fig. 3. 진을 SEM을 통하여 Fig. 3에 나타내었다. 또한 동일한 W/B와 PC 첨가량에서 F2>F1으로 F2가 유동성이 우수한 것으로 나타났는데 이는 분쇄에 의한 비표면적의 증가로 페이스트의 전체적인 충전율이 증가하여 구속수가 줄어 들어 F1보다 유동성이 증가된 것 으로 판단된다. 2,15) SEM photographs of BFS and FA powder. 제 45 권 제 6호(2008)

5 340 ká z Á yá Fig. 4. Rheological curves as a function of PC dosage for the samples with various W/B of BFS and FA (blaine 4000 cm 2 /g) (a) W/B 30%, (b) W/B 50%, and (c) W/B 70%. S1, F1 W/B 50, 70%, PC 0.5%, S2, F2 W/B 70%, PC 0.5% x BFS FA w. p t j w» w w w, p r p p ƒ kƒ 2 w k. 16) ù W/B PC ƒ w x ƒ p W/B PC ƒ y p r p š d mw Figs. 4, 5 ùkü. x y ùk w wz ü., w š w š»», r w w. w l v (Hysterisis Loop) z ƒ w š w w w p r p yƒ w q (Structural breakdown) ùkü ƒ w. PC ƒ W/B ƒ l v w ùkû. v x w W/B PC w BFSƒ FA w ùkü BFS ƒ FA l v w š F2ƒ F1 û ùkü.

6 š v yww p r p p 341 Fig. 5. Rheological curves as a function of PC dosage for the samples with various W/B of BFS and FA (blaine 8000 cm 2 /g) (a) W/B 30%, (b) W/B 50%, and (c) W/B 70%. d W/B 70%, PC 0.3% ƒ BFS FA ƒ w ùkü. S1, F1 W/B 50, 70%, PC 0.5%, S2, F2 W/B 70%, PC 0.5% x BFS FA w. W/B ƒ w PC ƒ ƒ w v w» yy w» x. 17) W/B 70% PC 0.3% d w, W/B ƒ w ü ùk ý ƒ. š w w w xz w Figs. 6, 7 ù kü. v x PC ƒ W/B ƒ w w š, ƒ w ùkü W/B 70%, PC 0.3% ƒ û w ùkü. w BFS w w ùkü FA w Ÿ p W/B w w ùkü. w FA BFS 1.3~1.9, w 1.6~1.9 ùkû. w t w ƒw, x w 18) š ƒ. w x 50 cps w, w 10 d/cm w ƒƒ 2 w xz PC ƒ W/B y xz w 45«6y(2008)

7 342 ká z Á yá Fig. 6. Change of Plastic Viscosity and Yield stress as function of PC dosage for the samples with various W/B of BFS and FA (blaine 4000 cm 2 /g) (a) W/B 30%, (b) W/B 50%, and (c) W/B 70%. ( þ : Segregation) w d ww y š wš Fig. 8 ùkü. y w, v d w w š, ƒƒ R( ) ùkü. w wz 4. PC ƒ W/B ƒ š v yww p r p p q w» w x w. 1. PC ƒ W/B ƒ v x d W/B 70%, PC 0.3% ƒ BFS FA ƒ w ùkü cps w, w 10 d/cm 2 w x. S1, F1 W/B 50, 70%, PC 0.5%, S2, F2 W/B 70%, PC 0.5% BFS FA w. 3. w FA BFS 1.3~1.9, w 1.6~1.9 ùkù FA j v w ùkû. 4. F2(8,100 cm 2 /g)ƒ F1(4,120 cm 2 /g) w ùkü. w t ƒ r p ƒw F1 ƒ q. 5. BFS W/B 30% PC0%, FA W/B 30% PC 0%, 0.3%, 0.5% v d ƒ w. FA y x

8 š v yww p r p p 343 Fig. 7. Change of Plastic Viscosity and Yield stress as fuuntion of PC dosage for the samples with various W/B of BFS and FA(blaine 8000 cm 2 /g) (a) W/B 30%, (b) W/B 50%, and (c) W/B 70%. ( þ : Segregation) Fig. 8. Rheological factors as a function of PC dosage for the samples with various W/B of BFS and FA.( stress & Plastic viscosity, (b) Mini-slump & Yield stress. : segregation) (a) Yield 45«6y(2008)

9 344 ká z Á yá x š, t ñ w w k w BFS ƒ. Acknowledgment 2008w w w,. REFERENCES 1. B. S. Lee, S. K. Kim, S. Y. Kim, S. M. Choi, and G. S. Lee, Examination on Application of High-Performance Concrete Using Fine Fly Ash as Replacement Material of Silica Fume, J. of the Korea Concrete Institute., 44 [9] (2007). 2. T. H. Park, M. H. Noh, and C. K. Park, Characterization of Rheology on the Multi-Ingredients Paste Systems Mixed with Mineral Admixtures, J. of the Korea Concrete Institute., 16 [2] (2004). 3. C. F. Ferraris, K. H. Obla, and R. Hill, The Influence of Mineral Admixtures on the Rheology of Cement Paste and Concrete, Cem. Concr. Res., 31 [2] (2001). 4. J. H. Sin, Rheological Properties and Early Hydration of Cement Paste Containing Mineral Admixtures, J. Kor. Ceram. Soc., 42 [11] (2005). 5. K. S. Wang and H. N. Hsieh, Pozzolanic Reactions in Municipal Solid Waste Incinerator Fly-ash-slag-blended Cements, Cem. Concr. Res., In Press, Corrected Proof (2004). 6. D. W. Yoo, S. H. Byun, and J. T. Song, Physical Properties of Ultrafine Ash Blended Cement, J. Kor. Ceram. Soc., 44 [9] (2007). 7. S. K. Yang, W. J. Lee, D. S. Kim, Y. S. Chung, J. S. Ryu, and J. R. Lee, Rheological Properties of Cement Using Admixtures, J. of the Korea Concrete Institute., 15 [1] (2003). 8. C. Jturapitakkul, K. Koattokomol, and V. Sata, Use of Ground Coarse Fly Ash as a Replacement of Cendensed Silica Fume in Producing High-strength Concrete, Cem. Concr. Res., 34 [4] (2004). 9. P. Termkhajornkit and T. Nawa, The Fluidity of Fly Ashcement Paste Containing Naphthalene Sulfonate Superplasticizer, Cem. Concr. Res., 34 [6] (2004). 10. V. S. Ramachandran, Mini Slump of Research Techniques, pp. 78-9, Concrete Admixtures Handbook, V. S. Ramachandran, Z. Shihua, and J. J. Beaudoin, Application of Miniature Tests for Workability of Superplasticizer Cement Systems, Il Cemento, (1988). 12. C. K. Park, M. H. Noh, H. Y. Kim, J. P. Lee, and T. H. Park, A Study on the Rheology Properties of Cement Paste with Variation of Quantity and Type of Mineral Admixture, J. of the Korea Concrete Institute., 15 [1] (2003). 13. Y. J. Choi, J. H. Kim, N. Y. Jee, and W. J. Kim, The Rheological Properties of Cement Paste Using Fly Ash and Slag Powder, J. of Architecture Institute of korea., 14 [6] (1998). 14. H. C. Shin, H. K. Kang, S. J. Choi, G. Y. Kim, J. M. Kim, and M. H. Kim, An Experimental Study on the Quality of High Flowing Concrete according to Ignition Loss of Flyash, J. of the Korea Concrete Institute., 9 [2] (1997). 15. E. K. Kim, C. S. Park, J. J. Choi, C. K. Jeon, and H. S. Lee, Properties of Self-Compacting Concrete Using Ground Granulated Blast Furnace Slag and Fly ash, J. of the Korea Concrete Institute., 15 [1] (2003). 16. J. J. Choi, Kinds and Properties of Superplasticizer, J. of the Korea Concrete Institute., 13 [1] 32-7 (2001). 17. I. S. Hwang, J. H. Jung, and J. T. Song, Effects of Soluble Alkalis on the Rheological Properties of Belite-rich Cement with Polycarbonate Superplasticizer, J. Kor. Ceram. Soc., 38 [2] (2001). 18. C. D. You, S. H. Byun, and J. T. Song, Rheological Properties of Cement Paste Containing Ultrafine Blastfurnace Slag, J. Kor. Ceram. Soc., 44 [8] (2007). w wz