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1 高強度鋼筋混凝土 (New RC) 結構設計與施工技術研討會高流動性應變硬化鋼纖維混凝土於 New RC 結構系統之應用廖文正副教授國立台灣大學土木工程學系

2 E c (10 5 kgf/cm 2 ) New RC 彈性模數? 5 E C = f c ( kgf cm 2) 932 筆資料,f c: 210 kgf/cm2~840 kgf/cm 2 間, 已考慮粗粒料含量 OPC SCC 卜作嵐添加量等敏感度分析 ACI318 ACI363 CEB-FIP78 CEB-FIP90 GZ&GL2000 土水建議公式資料點 f c '(kgf/cm 2 ) 廖文正 *, 林致淳, 詹穎雯 (2016 年 11 月 ) 台灣混凝土彈性模數建議公式研究結構工程期刊,31(3)

5 新世代耐震水泥質材料 - 高流動性應變硬化鋼纖維混凝土

6 背景臺灣 New RC Project 純鋼筋混凝土高樓建築 (50-story) 高強度混凝土 (>70MPa)+ 高強度鋼筋, 減少斷面尺寸材料用量及建物自重, 增加使用空間 x 脆性破壞, 需更多箍筋圍束普通強度混凝土高強度混凝土現行規範 ACI 箍筋量增加 70%, 180 o 彎鈎

7 背景

8 背景 ACI Minimum shear reinforcement (f) Beams constructed of steel fiber-reinforced, normalweight concrete with f c not exceeding 6000 psi, h not greater than 24 in., and V u not greater than 2 f c b w d. R (f) This exception is intended to provide a design alternative to the use of shear reinforcement, as defined in , for members with longitudinal flexural reinforcement in which V u does not exceed 2 f c b w d. Fiber-reinforced concrete beams with hooked or crimped steel fibers in dosages as required by have been shown, through laboratory tests, to exhibit shear strengths larger than 3.5 f c b w d.

9 背景高流動性應變硬化鋼纖維混凝土 : 高剪力強度高圍束效益, 能直接取代箍筋, 簡化斷面配筋設計臺灣 New RC 未來應用構件配比設計基本材料力學行為組合律剪力牆剪力牆 Wen-Cheng Liao, Wisena Perceka, En-Jui Liu (2015, Aug). Compressive Stress-Strain Relationship of High Strength Steel Fiber Reinforced Concrete. Journal of Advanced Concrete Technology, 13, pp (SCI). Wen-Cheng Liao, Shih-Ho Chao (2015, Mar). Crack Opening Evaluation and Sustainability Potential of Highly Flowable Strain-Hardening Fiber-Reinforced Concrete (HF-SHFRC). Journal of Testing and Evaluation, 43(2), pp (SCI). 梁柱接頭 ( 高剪力及變形容限需求 ) 底層柱 ( 高軸力高剪力需求之柱 ) 耦合梁剪力牆底部梁塑鉸 ( 高剪力及彎矩需求 ) ( 高剪力及彎矩需求 )

10 Main Obstacles for Fiber Reinforced Concrete 1. Workability 2. Mechanical performances is not as good as expected. Sol: Highly Flowable Strain Hardening Fiber Reinforced Concrete, HF-SHFRC 3. No main advantages on usual structural applications. Sol: New RC project, bridge piers, beam-column joint, base columns and etc.

11 Highly Flowable Strain Hardening Fiber Reinforced Concrete V f =1.5%; f c = 70 MPa

12 Highly Flowable Strain Hardening Fiber Reinforced Concrete

13 Highly Flowable Strain Hardening Fiber Reinforced Concrete 1. Unlike traditional HPFRCC, coarse aggregate is used in HF-SHFRC. 2. Slag and Fly ash (sustainable construction material) substitution of cement up to 50%.

14 Experimental Program Confinement Efficiency: Proposed Toughness Ratio Wisena Perceka, Wen-Cheng Liao* and Yo-de Wang (2016, Apr). High Strength Concrete Columns under Axial Compression Load: Hybrid Confinement Efficiency of High Strength Transverse Reinforcement and Steel Fibers. Materials, 9(4), 264; DOI: /ma (SCI)

15 Toughness Ration, TR Instead of P o, TR is used for confinement design. 1. P o is not that well described in New RC. 2. Addition of fiber would not significantly affect P o. P or σ P u or σ u A TR = Area OABC (P u or σ u ) x B 0 C ε

16 Proposed Toughness Ratio Equation k e = confinement effectiveness coefficient ρ s = transverse reinforcement ratio f yt = yield strength of transverse reinforcement f c = compressive strength of concrete

17 Proposed Toughness Ratio Equation k e = confinement effectiveness coefficient ρ s = transverse reinforcement ratio f yt = yield strength of transverse reinforcement f c = compressive strength of concrete V f = steel fiber volume fraction L/φ = aspect ratio of steel fiber X f = fiber efficiency factor in terms of stirrups spacing τ eq = equivalent bond strength

18 Specimen design Column size: (cm) Section:

19 Specimen design Specimen ID Stirrups spacing (mm) Stirrups spacing / Effective depth S % S80_SF % S % S120_SF % S % S170_SF % S % S340_SF % V f

20 Test results S80 & S80_SF0.75 S80 S80_SF0.75

21 Test results S120 & S120_SF1.0 S120 S120_SF1.0

22 Test results S170 & S170_SF1.5 S170 S170_SF1.5

23 Test results S340 & S340_SF0.75 S340 S340_SF1.5

24 Failure modes w/o fibers S80 S120 S170 S340 w/ fibers S80_SF0.75 S120_SF1.0 S170_SF1.5 S340_SF1.5

25 TR verification Specimen ID Error S % S80_SF % S % S120_SF % S % S170_S % S % S340_SF %

26 Experimental Program Lateral cyclic behavior of HF-SHFRC Columns

27 Experimental Program Multi-Axial Resting System (MATS) Axial loading capacity: up to 60 MN Cross Beam National Center for Research on Earthquake Engineering (NCREE) P l a t e n Platen Lateral actuator

28 Experimental Program Drift Ratio (%) Loading Protocol 0.25% 0.375% 0.50% 0.75% 1.00% 1.50% 2.00% Cycle 3.00% 4.00% 5.00% 6.00% 7.00% 8.00% Ref: ACI Committee 374, Acceptance Criteria for Moment Frames Based on Structural Testing and Commentary(ACI ), American Concrete Institute, Passing Criteria: Ultimate drift ratio, UDR (drift ratio corresponding to 80% Max lateral capacity) > 3.0%

29 Experimental Program No. Section s (mm) TR S140-0 (ACI ) #8, SD685 #4, SD S (V f = 1.5%) #8, SD685 #4, SD S (V f = 1.5%) #8, #10, SD (#5, SD785) 260 (d/2)

30 Test Results S140-0 (UDR: 1.25%) VS. S (UDR: 3.23%)

31 Test Results Failure S140-0 (2 nd cycle of 1.5%) S (4.0%)

32 Test Results Test Results (S ) failure UDR= 3.15%

33 Experimental Program External Beam Column Joint

34 Precast Technology

35 梁柱接頭 ( 鋼筋量極高 : 柱主筋 + 柱箍筋 + 梁主筋 ) 現行規範完全移除梁柱接頭箍筋, 以高流動性應變硬化鋼纖維混凝土澆置

36 Experimental Program Design Parameters Specimen Section LAMV* LAMV_SF HAMV* HAMV_SF 2.25 (16-#8) 2.25 (16-#8) 2.25 (16-#8) 2.25 (16-#8) * 趙偉帆, 使用擴頭鋼筋錨定之高強度鋼筋混凝土梁柱接頭在 P-δ 效應下耐震行為研究, 國立台灣科技大學營建工程系,2016

$5% Volume fraction of steel fiber$

37 Specimen layout LAMV HAMV Low axial load Moderate shear ratio 1.5% Volume fraction of steel fiber LAMV_SF HAMV_SF s = 100mm Steel Fiber s = depth of beam = 700mm

38 Casting

39 Experiment Setup

40 P-delta effect

41 Result and discussion LAMV v.s LAMV_SF

42 Result and discussion LAMV v.s LAMV_SF B type B type

43 Result and discussion Specimen Failure mode LAMV B kn 8 % LAMV_SF B kn 8 %

44 Result and discussion

45 Conclusions 1) Addition of fibers provides high ductility to brittle concrete, particularly for high strength concrete (NEW RC). 2) Compared to HSC, HF-SHFRC presents high toughness, damage tolerance and excellent shear capacity while allowing good workability. 3) The experimental results shows that addition of fibers can be an effective alternative for transverse reinforcement in NEW RC buildings. 4) By increasing the spacing to d/2 and under 0.43 A g f c axial loading level, excellent performance and damage tolerance can be still observed in S It shows the great potential to apply HF- SHFRC to NEW RC columns.

46 Conclusions 5) By using HF-SHFRC, the lateral reinforcement can be completely eliminated in NEW RC external beam-column joints under 0.1 A g f c axial loading. 6) To Implement HF-SHFRC in NEW RC Precast systems, its excellent mechanical properties also offer the opportunity to significantly simplify the design and construction and push the practice achieving higher levels of performance and safety.

47 Thank you 國立台灣大學土木工程學系副教授廖文正

Fig. 1 Frame calculation model 1 mm Table 1 Joints displacement mm

Fig. 1 Frame calculation model 1 mm Table 1 Joints displacement mm 33 2 2011 4 ol. 33 No. 2 Apr. 2011 1002-8412 2011 02-0104-08 1 1 1 2 361003 3. 361009 3 1. 361005 2. GB50023-2009 TU746. 3 A Study on Single-span RC Frame Reinforced with Steel Truss System Yuan Xing-ren