本研究旨在探討高強度鋼筋混凝土梁使用高強度焊接剪力鋼筋來代替135度耐震彎鉤剪力鋼筋的可行性，並驗證高強度剪力鋼筋使用設計強度550MPa是否合理。本論文共測試三座高強度鋼筋混凝土梁，實驗結果顯示焊接型剪力鋼筋比135度耐震彎鉤更有效的增進試體的變形能力與位移韌性，試體使用焊接型高強度剪力鋼筋的試體在VnL/Mpr=0.65的設計剪力強度可以達到極限層間位移量6.00%，增加VnL/Mpr至2.00會改變試體的破壞模式但是對提升層間位移量的影響有限，而高強度剪力鋼筋使用設計強度550MPa應屬合理，另外使用試體設計公式可以保守預測試體的彎矩強度。

The potential of using welded high-strength steel as shear reinforcement in the high-strength reinforced concrete (RC) beam members is studied in this research. A total of three high-strength RC beam specimens are tested. Experimental results show that the specimen with welded hoops exhibits better deformation capacity and ductility compared to the specimen with seismic hoops consisting of 135 degree standard seismic hooks. With the provided shear-to-probable moment capacity of VnL/Mpr =0.65, the specimens with welded hoop failed at ultimate drift ratio of 6.00%. An increase of VnL/Mpr ratio to 2.00 does not improve the deformation capacity further but changes the failure mode from flexure-shear to flexure failure. Based on the observations, an upper bound of 550 MPa may be reasonable assumed as the designed strength of the high-strength stirrup, specifically SD785 high-strength steel. The proposed equations to evaluate the flexural strength of high-strength beam specimens also provide reasonable and conservative predictions.

1.Municrishna, A.; Hosny, A.; Rizkalla,S.; and Zia, P., “Behaviour of Concrete Beams Reinforced with ASTM A1035 Grade 100 Stirrups under Shear,” ACI Structural Journal, V. 108, No. 1, Jan.-Feb., 2011, pp.34-41.

2.Lin, C.H.; Lee, F.S., “Ductility of High-Performance Concrete Beams with High-Strength Lateral Reinforcement,” ACI Structural Journal, V. 98, No. 4, July-Aug.,2001, pp.600-608.

3.Lee, J. Y.;Choi, I. J.; and Kim, S. W., “Shear Behavior of Reinforced Concrete Beams with High-Strength Stirrups.” ACI Structural Journal, V. 108, No. 5, Sept.-Oct.,2011, pp. 620-629.

4.Sumpter, M. W.;Rizkalla, S. H.; and Zia,P., “Behavior of High-Performance Steel as Shear Reinforcement for Concrete Beams.” ACI Structural Journal, V. 106, No. 2, March-April, 2009, pp. 171-177.

5.Mattock, A. H.; Kriz, L. B.; and Hognestad, E., “Rectangular Concrete Stress Distribution in Ultimate Strength Deisgn,” Journal of the American Concrete Institute, Vol. 57, No. 8, Feb., 1961, pp. 875-929.

6.Whitney, C. S., “Design of Reinforced Concrete Members under Flexure or Combined Flexural and Direct Compression,” Journal of the American Concrete Institute, Proceedings Vol. 33, No. 3, March, 1937, pp. 483-498.

7.Nedderman, H., “Flexrual Stress Distribution in Very High Strength Concrete,” M.S. thesis, Department of Civil Engineering, University of Texas, Austin, Texas, 1973, 182 pp.

8.CSA A23.3-04, “Design of Concrete Structures,” Canadian Standards Association, Rexdale, Ontario, Canada, 2004, 232 pp.

9.Mertol, H. C.; Rizkalla, S.; Zia, P.; and Mirmiran, A., “Characteristics of Compressive Stress Distribution in High-Strength Concrete,” ACI Structural Journal, Vol. 105, No. 5, Sept.-Oct., 2008, pp. 626-633.

10.Khadiranaikar, R. B. and Awati, M. M., “Concrete Stress Distribution Factors for High-Performance Concrete,” Journal of Structural Engineering, Vol. 138, No. 3, March, 2012, pp. 402-415.

11.Bae, S. and Bayrak, O., “Stress Block Parameters for High-Strength Concrete Members,” ACI Structural Journal, Vol. 100, No. 5, Sept.-Oct., 2003, pp. 626-636.

12.Ibrahim, H. H. H. and MacGregor, J. G., “Modification of the ACI Rectangular Stress Block for High-Strength Concrete,” ACI Structural Journal, Vol. 94, No. 1, Jan.-Feb., 1997, pp. 40-48.

13.Azizinamini, A.; Kuska, S. S. B.; Brungardt, P.; and Hatfield, E., “Seismic Behavior of Square High-Strength Concrete Columns,” ACI Structural Journal, Vol. 91, No. 3, May-June, 1994, pp. 336-345.

14.Ozbakkaloglu, T. and Saatcioglu, M., “Rectangular Stress Block for High-Strength Concrete,” ACI Structural Journal, Vol. 101, No. 4, July-Aug., 2004, pp. 475-483.

15.ACI Committee 318, “Building Code Requirements for Reinforced Concrete (ACI 318-56)”, American Concrete Institute, Detroit, Michigan, 1956, pp.913-986

16.ACI Committee 318, “Building Code Requirements for Reinforced Concrete (ACI 318-71),” American Concrete Institute, Detroit, Michigan, 1971, 78 pp.

17.ACI Committee 318, “Building Code Requirements for Reinforced Concrete (ACI 318-77)”, American Concrete Institute, Detroit, Michigan, 1977, 103 pp.

18.ACI Committee 318, “Building Code Requirements for Structural Concrete (ACI 318-11) and Commentary,” American Concrete Institute, Farmington Hills, Mich., 2011, 503 pp.
19.Saatcioglu, M.; Grira, M., “Confinement of Reinforced Concrete Columns with Welded Reinforcement Grids,” ACI Structural Journal, V. 96, No. 1, Jan.-Feb.,1999, pp.29-39.

20.Aoyama, H., 2001, “Design of Modern High-Rise Reinforced Concrete Structures,” Series of Innovation in Structures and Construction, V. 3, Imperial College, London, 442 pp.

21.ACI Innovation Task Group 4, 2007, “Report on Structural Design and Detailing for High-Strength Concrete in Moderate to High Seismic Applications (ITG-4.3R-07),” American Concrete Institute, Farmington Hills, Mich., 62 pp.

22.Risser, B. and Humphreys, S.. 2008, “High-Strength Reinforcing Steel: Next Generation or Niche”, Concrete Construction, Jan,2008, Vol. 53 Issue 1, p57

23.Risser, B. and Hoffman, M., 2011, “Reinforcing Congestion”, Concrete Construction, Jan,2011, Vol. 56 Issue 1, p16.

24.ASTM A706/A706M-13, “Standard Specification for Low-Alloy Steel Deformed and Plain Bars for Concrete Reinforcement.”ASTM International, West Conshohocken, PA, 2013, 7 pp.

25.ASTM A1035/A1035M-13, “Standard Specification for Deformed and Plain,Low-Carbon, Chromium, Steel Bars for Concrete Reinforcement.”ASTM International, West Conshohocken, PA, 2013, 6 pp.