Journal of the Architectural Institute of Korea Structure & Construction (대한건축학회논문집:구조계)

Architectural Institute of Korea (대한건축학회)
권호 표지
DOI QR코드

DOI QR Code

Seismic Performance of RC Columns with Lap Splices at Plastic Hinge Region

소성힌지 구간에서 겹침이음된 RC기둥의 내진성능

  • Received : 2015.10.01
  • Accepted : 2015.12.10
  • Published : 2015.12.30
⟨ Previous Next ⟩

Abstract

For small buildings designed to primarily resist gravity load, lap splices of longitudinal reinforcement are used in columns at the regions (e.g. at the bottom of the $1^{st}$ floor) where flexural yielding is anticipated. Although not allowed under cyclic loading repeated in large inelastic range, such splices can be used as an alternative for the convenience of construction in small buildings where a limited ductility is required. In this study, cyclic loading test was performed for columns using lap splices at the plastic hinge regions. The length and offset bar details of lap splices and the ratio of shear span and section height (or aspect ratio) were considered as the test parameters. Non-seismic hoops of 90-degree end hooks were provided over the lap length. Test results showed that the strength and ductility of columns were significantly varied depending on the offset bar details and length of lap splices. In addition, the aspect ratio also had significant impact on the performance of lap splices due to change of the bond demand in the splice zone. The columns lap spliced in the plastic hinge zone were vulnerable to vertical cracking (or concrete splitting) along the lap length. Based on the test results and the review of existing studies, design recommendations for calculating lap spliced length of columns at plastic hinge zone were proposed.

Keywords

Acknowledgement

Supported by : 국토교통부

References

  1. Aboutaha, R., Engelhardt, M., Jirsa, J., & Kreger, M. (1999). Experimental investigation of seismic repair of lap splice failures in damaged concrete columns. ACI Structural Journal, 96(2), 297-306.
  2. ACI Committee 315. (1999). BDetails and Detailing of Concrete Reinforcement(ACI 315-99). American Concrete Institute, 1-44.
  3. ACI Committee 318. (1956). Building Code Requirements for Reinforced Concrete(ACI 318-56). American Concrete Institute, Farmington Hills, 1-73.
  4. ACI Committee 318. (1977). Building Code Requirements for Reinforced Concrete(ACI 318-77). American Concrete Institute, Farmington Hills, 1-103.
  5. ACI Committee 318. (2011). Building Code Requirements for Structural Concrete(ACI 318-11) and Commentary. American Concrete Institute, Farmington Hills, 1-503.
  6. ACI Committee 374.2R-13. (2005). AGuide for testing reinforced concrete structural elements under slowly applied simulated seismic loads. American Concrete Institute, 1-18.
  7. Bournas, D., Triantafillou, T., Zygouris, K., & Stavropoulos, F. (2009). Textile-reinforced mortar versus FRP jacketing in seismic retrofitting of RC columns with continuous or lap-spliced deformed bars. Journal of Composites for Construction, 13(5), 360-371. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000028
  8. Boyes, A., Bull, D., & Pampanin, S. (2008). Seismic performance of concrete columns with inadequate transverse reinforcement. 1-12.
  9. ElGawady, M., Endeshaw, M., McLean, D. & Sack R. (2010). Retrofitting of Rectangular Columns with Deficient Lap Splices. Journal of Composites for Construction, 14(1), 22-35. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000047
  10. Harajli, M. (2008). Seismic Behavior of RC Columns with Bond-Critical Regions: Criteria for Bond Strengthening Using External FRP Jackets. Journal of Composites for Construction, 12(1), 69-79. https://doi.org/10.1061/(ASCE)1090-0268(2008)12:1(69)
  11. Haroun, M., & Elsanadedy, H. (2005). Fiber-reinforced plastic jackets for ductility enhancement of reinforced concrete bridge columns with poor lap-splice detailing. Journal of Bridge Engineering, 10(6), 749-757. https://doi.org/10.1061/(ASCE)1084-0702(2005)10:6(749)
  12. Harries, K., Ricles, J., Pessiki S. & Sause R. (2006). Seismic retrofit of lap splices in nonductile square columns using carbon fiber-reinforced jackets. ACI Structural Journal, 103(6), 874-84.
  13. KCI 2012. (2012). Building Code for Structural Concrete and Commentary. Korea Concrete Institute, Kimoondang, 1-599.
  14. KSEA. (2012). Structural design criteria and commentary for one and two story small buildings. Korean Structural Engineers Association, 39-69.
  15. Lynn, A., Moehle, J., Mahin, S., & Holmes, W. (1996). Seismic evaluation of existing reinforced concrete building columns. Earthquake Spectra, 12(4), 715-739. https://doi.org/10.1193/1.1585907
  16. Melek, M., & Wallace, J. (2004). Cyclic behavior of columns with short lap splices. ACI Structural Journal, 101(6), 802-811.
  17. Park, H., Yu, E., & Choi, K. (2012). Shear-strength degradation model for RC columns subjected to cyclic loading. Engineering Structures, 34, 187-197. https://doi.org/10.1016/j.engstruct.2011.08.041
  18. Priestley, M., Verma, R., & Xiao, Y. (1994). Seismic Shear-Strength of Reinforced-Concrete Columns. Journal of Structural Engineering, 120(8), 2310-2327. (Received Oct. 1 2015 Revised Nov. 4 2015 Accepted Dec. 10 2015) https://doi.org/10.1061/(ASCE)0733-9445(1994)120:8(2310)