This study addresses the critical issue of splitting bond failure in high-strength reinforced concrete (HSRC) columns, a phenomenon that significantly impacts structural ductility and energy-dissipating capacity. Current codes, such as ACI 318-19, impose minimum column height limitations to mitigate the risk of splitting failure in short columns under lateral loads. However, existing codes and standard bond strength tests do not adequately characterize bond strength in HSRC columns. The employed testing model in this study provides a comprehensive overview of bond strength in HSRC columns. The study aims to investigate bond stress, assess the potential for splitting bond failure, and propose a method for conducting bond strength experiments in HSRC columns. Specific objectives include exploring the influence of axial force on bond strength, suggesting methods for estimating bond strength and development length and establishing minimum height criteria to mitigate the risk of splitting bond failure.
To achieve these objectives, the study integrates experimental data generated within its scope and incorporates previous experimental findings to observe the effects of axial load on bond strength capacity in HRRC columns. Utilizing a column bond test model, the study characterizes bond behavior in columns subjected to both axial and lateral loads. Specimens include HSRC columns with transverse reinforcement at intervals of 75 mm, 100 mm, 150 mm, and 200 mm. Test results reveal that tighter stirrups correlate with higher bond strength, and an increase in axial load leads to a reduction in bond capacity. Finite Element Analysis (FEA) validates these findings. Additionally, the study highlights that columns with higher bond strength and well-confined HSRC columns can be designed with a shorter height than recommended by codes. FEA simulations support the proposed reduction in HSRC column height, validating the suggested bond strength formulation. Implications of the study encompass providing design recommendations to minimize the risk of splitting bond failure in HSRC columns and enhancing structural safety against seismic forces.

Keywords: High Strength Reinforced Concrete, Bond Strength in HSRC Column, Splitting Bond Failure, Minimum Column Height, Finite Element Analysis

[1] ACI Committee 318, Building code requirements for structural concrete (ACI 318-19) an ACI standard (SI unit), and Commentary (ACI 318R-19) Reported by ACI committee 318. ACI, 2019.
[2] AIJ, AIJ standard for Structural Calculation of Reinforced Concrete Structures Revised 2010. 2010.
[3] ACI Committee 408, Bond and Development of Straight Reinforcing Bars in Tension Reported by ACI Committee 408. 2003.
[4] R. Park and T. Paulay, Reinforced Concrete Structures. John Wiley & Sons, Ltd, 1975. doi: 10.1002/9780470172834.fmatter.
[5] M. R. Esfahani and B. V. Rangan, “Local bond strength of reinforcing bars in normal strength and High-Strength Concrete (HSC),” ACI Struct. J., vol. 95, no. 2, pp. 96–106, 1998, doi: 10.14359/530.
[6] A. M. Diab, H. E. Elyamany, M. A. Hussein, and H. M. Al Ashy, “Bond behavior and assessment of design ultimate bond stress of normal and high strength concrete,” Alexandria Eng. J., vol. 53, no. 2, pp. 355–371, 2014, doi: 10.1016/j.aej.2014.03.012.
[7] H. Yalciner, O. Eren, and S. Sensoy, “An experimental study on the bond strength between reinforcement bars and concrete as a function of concrete cover, strength and corrosion level,” Cem. Concr. Res., vol. 42, no. 5, pp. 643–655, 2012, doi: 10.1016/j.cemconres.2012.01.003.
[8] M. N. S. Hadi, “Bond of High Strength Concrete with High Strength Reinforcing Steel,” Open Civ. Eng. J., vol. 2, no. 1, pp. 143–147, 2008, doi: 10.2174/1874149500802010143.
[9] J. E. Orangun, C. O.; Jirsa, J. O.; and Breen, “A Reevaluation of Test Data on Development Length and Splices,” ACI J., vol. Proceeding, pp. 114–122, 1977.
[10] ACI-318M, Building Code Requirements for Structural Concrete (ACI 318M-14) and Commentary (ACI 318RM-14). 2014.
[11] NCREE, “Design Guideline for Building of High-Strength Reinforced Concrete Structures (Draft),” 2019.
[12] K. N. Chi, C. K. Chiu, and K. C. Lin, “Study on straight development length of tensile threaded bars in high-strength reinforced concrete members,” Constr. Build. Mater., vol. 183, pp. 661–674, 2018, doi: 10.1016/j.conbuildmat.2018.06.180.
[13] T. Ichinose, “Conditions for Preventing Bone Failure in Short Columns Reinforced Concrete (in Japan),” AIJ Proc., vol. 338, 1984.
[14] H. Wang, “An analytical study of bond strength associated with splitting of concrete cover,” Eng. Struct., vol. 31, no. 4, pp. 968–975, 2009, doi: 10.1016/j.engstruct.2008.12.008.
[15] A. Torre-Casanova, L. Jason, L. Davenne, and X. Pinelli, “Confinement effects on the steel-concrete bond strength and pull-out failure,” Eng. Fract. Mech., vol. 97, no. 1, pp. 92–104, 2013, doi: 10.1016/j.engfracmech.2012.10.013.
[16] X. Gao, N. Li, and X. Ren, “Analytic solution for the bond stress-slip relationship between rebar and concrete,” Constr. Build. Mater., vol. 197, no. 2, pp. 385–397, Feb. 2019, doi: 10.1016/j.conbuildmat.2018.11.206.
[17] T. Ichinose, “Splitting bond failure of columns under seismic action,” ACI Mater. J., vol. 92, no. 5, pp. 535–542, 1995, doi: 10.14359/904.
[18] D. Sokoli and W. M. Ghannoum, “High-strength reinforcement in columns under high shear stresses,” ACI Struct. J., vol. 113, no. 3, pp. 605–614, 2016, doi: 10.14359/51688203.
[19] F. J. Vecchio and M. P. Collins, “Modified Compression-Field Theory for Reinforced Concrete Elements Subjected To Shear.,” J. Am. Concr. Inst., vol. 83, no. 2, pp. 219–231, 1986, doi: 10.14359/10416.
[20] E. HOGNESTAD, N. W. HANSON, and D. McHENRY, “Concrete Stress Distribution in Ultimate Strength Design,” Adolesc. Psychiatry (Hilversum)., vol. 20, no. 52, pp. 455–479, 1995.
[21] DIANA FEA, “DIANA FEA 10.4 User’s Manual.” DIANA FEA, Delft, Netherlands, 2020.
[22] CEB-FIP, fib Model Code 2010. Lausanne, Switzerland: International Federation for Structural Concrete (fib), 2012.
[23] C. K. Chiu, S. Sugianto, W. I. Liao, and C. E. Ho, “Crack-based damage quantification for shear-critical HSRC column members using piezoceramic transducers,” Eng. Struct., vol. 201, no. September, 2019, doi: 10.1016/j.engstruct.2019.109777.
[24] D. Cusson and P. Paultre, “High-Strength Concrete Columns Confined by Rectangular Ties,” J. Struct. Eng., vol. 120, no. 3, pp. 783–804, 1994.
[25] H. O. Shin, Y. S. Yoon, W. D. Cook, and D. Mitchell, “Axial load response of ultra-high-strength concrete columns and high-strength reinforcement,” ACI Struct. J., vol. 113, no. 2, pp. 325–336, 2016, doi: 10.14359/51688063.
[26] H. O. Shin, Y. S. Yoon, W. D. Cook, and D. Mitchell, “Effect of Confinement on the Axial Load Response of Ultrahigh-Strength Concrete Columns,” J. Struct. Eng., vol. 141, no. 6, pp. 1–12, 2015, doi: 10.1061/(asce)st.1943-541x.0001106.
[27] S. R. Razvi and M. Saatcioglu, “Circular high-strength concrete columns under concentric compression,” ACI Struct. J., vol. 96, no. 5, pp. 817–825, 1999, doi: 10.14359/736.
[28] F. Légeron and P. Paultre, “Uniaxial Confinement Model for Normal- and High-Strength Concrete Columns,” J. Struct. Eng., vol. 129, no. 2, pp. 241–252, 2003, doi: 10.1061/(asce)0733-9445(2003)129:2(241).
[29] M. Valcuende and C. Parra, “Bond behaviour of reinforcement in self-compacting concretes,” Constr. Build. Mater., vol. 23, no. 1, pp. 162–170, 2009, doi: 10.1016/j.conbuildmat.2008.01.007.
[30] I. Pop, G. De Schutter, P. Desnerck, and T. Onet, “Bond between powder type self-compacting concrete and steel reinforcement,” Constr. Build. Mater., vol. 41, pp. 824–833, 2013, doi: 10.1016/j.conbuildmat.2012.12.029.
[31] A. H. Mattock, “Rotational capacity of hinging regions in reinforced concrete beams,” Am. Concr. Institute, ACI Spec. Publ., vol. SP-012, pp. 143–181, 1965.
[32] S. Bae and O. Bayrak, “Plastic Hinge Length of Reinforced Concrete Columns,” ACI Struct. J., vol. 105-S28, pp. 290–300, 2008.
[33] M. P. Berry, D. E. Lehman, and L. N. Lowes, “Lumped-plasticity models for performance simulation of bridge columns,” ACI Struct. J., vol. 105, no. 3, pp. 270–279, 2008, doi: 10.14359/19786.
[34] Y. C. Ou, R. A. Kurniawan, D. P. Kurniawan, and N. D. Nguyen, “Plastic hinge length of circular reinforced concrete columns,” Comput. Concr., vol. 10, no. 6, pp. 663–681, 2012, doi: 10.12989/cac.2012.10.6.663.
[35] fib, fib CEB-FIP Model Code 2010, vol. 2, no. 1. International Federation for Structural Concrete (fib), 2010.
[36] JBDPA, Guideline for post-earthquake damage evaluation and rehabilitation. Tokyo, Japan: Japan Building Disaster Prevention Association, 2001.
[37] ASCE, Minimum design loads and associated criteria for buildings and other structures, ASCE/SEI 7. Virginia: American Society of Civil Engineers, 2017. doi: 10.1061/9780784414248.