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Anchorage Strength of Headed Bars in Steel Fiber-Reinforced UHPC of 120 and 180 MPa
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 Title & Authors
Anchorage Strength of Headed Bars in Steel Fiber-Reinforced UHPC of 120 and 180 MPa
Sim, Hye-Jung; Chun, Sung-Chul; Choi, Sokhwan;
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Ultra-High-Performance Steel Fiber-Reinforced Concrete (SUPER Concrete) exhibits improved compressive and tensile strengths far superior to those of conventional concrete. These characteristics can significantly reduce the cross sectional area of the member and the anchorage strength of a headed bar is expected to be improved. In this study, the anchorage strengths of headed bars with or embedment length were evaluated by simulated exterior beam-column joint tests where the headed bars were used as beam bars and the joints were cast of 120 or 180 MPa SUPER Concrete. In all specimens, the actual yield strengths of the headed bars over 600 MPa were developed. Some headed bars were fractured due to the high anchorage capacity in SUPER Concrete. Therefore, the headed bar with only embedment length in 120 MPa SUPER Concrete can develop a yield strength of 600 MPa which is the highest design yield strength permitted by the KCI design code. The previous model derived from tests with normal concrete and the current design code underestimate the anchorage capacity of the headed bar anchored in SUPER Concrete. Because the previous model and the current design code do not consider the effects of the high tensile strength of SUPER Concrete. From a regression analysis assuming that the anchorage strength is proportional to , the model for predicting anchorage strength of headed bars in SUPER Concrete is developed. The average and coefficient of variation of the test-to-prediction values are 1.01 and 5%, respectively.
steel fiber-reinforced concrete;headed bar;anchorage strength;embedment length;
 Cited by
Hong, K.N., Kang, S.T., Kim, S.W., Park, J.J., and Han, S.H., "Material properties of air-cured ultra-high-performance steel-fiber-reinforced concrete at early ages," International Journal of the Physical Sciences, Vol.5, No.7, 2011, pp. 2622-2634.

Karl, K.-W., Lee, D.H., Hwang, J.-H., Kim, K.S., and Choi, I.-S., "Revision on material strength of steel fiber-reinforced concrete," International Journal of Concrete Structures and Materials, Vol.5, No.2, 2011, pp.87-96. crossref(new window)

Park, S.H., Kim, D.J., Ryu, G.S., and Koh, K.T., "Tensile behavior of ultra high performance hybrid fiber reinforced concrete," Cement and Concrete Composites, Vol.34, No.2, 2012, pp.172-184. crossref(new window)

Yang, I.H., Cho, C.B., and Kim, B.S., "Flexural response predictions for ultra-high performance fiber-reinforced concrete beams," Magazine of Concrete Research, Vol.64, No.2, 2012, pp.113-127. crossref(new window)

Wallace, J.W., "Headed Reinforcement: A Viable Option," Concrete International, V. 19, No. 12, Dec. 1997, pp.47-53.

Berner, D.E., and Hoff, G.C., "Head Reinforcement in Disturbed Strain Regions of Concrete Members," Concrete International, V. 16, No. 1, Jan. 1994, pp.48-52.

Wallance, J.W.; McConnell, S.W.; Gupta, P.; and Cote P.A., "Use of Headed Reinforcement in Beam-Column Joints Subjected to Earthquake Loads," ACI Structural Journal, V. 95, No. 5, Sept.-Oct., 1998, pp.590-606.

Korea Concrete Institute, Concrete Design Code, Kimoondang Publishing Company, Seoul, 2012, 342 pp.

Marques, J. L. G. and Jirsa, J. O., "A Study of Hooked Bar Anchorages in Beam-Column Joints," ACI Journal, Proceedings, Vol.72, No.5, 1975, pp.198-209.

Choi, C. M., "Strength of Headed Bars Anchored in CCT Nodes," Master thesis of Mokpo National University, Feb. 2014, 70 pp.

Thompson, M.K., Jirsa, J.O., and Breen, J.E., "Behavior and Capacity of Headed Reinforcement," ACI Structural Jounal, Vol.103, No.4, Jul.-Aug., 2006, pp.522-530.

ACI Committee 318, "Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary," ACI, Farmington Hills, Mich, USA, 2014, 492 pp.

Furche, J. and Eligehausen, R., "Lateral Blow-Out Failure of Headed Studs Near a Free Edge," Anchors in Concrete-Design and Behavior, SP-130, 1991, American Concrete Institute, Farmington Hills, MI. USA, pp.235-252.

Korea Institute of Civil Engineering and Building Technology, "Design Guidelines for K-UHPC," Feb. 2014, 90 pp.

ACI Committee 352, "Recommendations for Design of Beam-Column Connections in Monolithic Reinforced Concrete Structures," ACI, Farmington Hills, Mich., USA, 2002, 38 pp.

KS B 0802:2003, Method of Tensile Test for Metallic Materials, Korean Agency for Technology and Standards, 2003, 7 pp.