Effect of Deformed and Plain Rebars on the Behavior of Lightly Reinforced Boundary Elements

Document Type : Regular Paper


Department of Civil Engineering, Faculty of Engineering, Urmia University, Urmia, Iran


In recent earthquakes common failure modes of lightly reinforced shear walls includes rebar fracture and out of plane buckling of boundary elements. In latest edition of ACI 318 and also latest amendment of NZS 3101-2006 to avoid rebar fracture in boundary elements, minimum longitudinal reinforcement ratio is increased. This experimental study investigates that rather than increasing the reinforcement ratio, is it possible to avoid rebar fracture by use of plain rebars in the critical sections of boundary elements in lightly reinforced shear walls. Experimental program includes specimens with plain and deformed rebars tested under monotonic and cyclic loading. Strain profile of the rebars are evaluated employing correlation between hardness and residual strain. Results indicate that failure of specimens with plain rebars occurs on single crack, however they have more uniform strain profile. On the other hand, in the specimens with plain and deformed rebars, out of plane buckling occurs at same crack width, but different elongations. It is shown that local strain demand (crack width) has better correlation with out of plane buckling in comparison with average axial strain.


Main Subjects

[1] Lu, Y., Henri, R.S., Ma, Q.T. (2014). “Numerical modelling and testing of concrete walls with minimum vertical reinforcement.” NZSEE conference.
[2] ACI 318-19 (2019). “Building code requirements for structural concrete (ACI 318-19) and commentary.” American Concrete Institute, Farmington Hills, MI.
[3] Priestley, M.J.N., Seible, F., Calvi, G.M. (1996). “Seismic design and retrofit of bridges.” John Wiley and Sons, NY, 686 p., doi:10.1002/9780470172858.
[4] Arteta, C.A., To, D.V., Moehle, J.P. (2014). “Experimental response of boundary elements of code-compliant reinforced concrete shear walls.” Tenth U.S. National Conference on Earthquake Engineering: Frontiers of Earthquake Engineering, Anchorage, Alaska, doi:10.4231/D37H1DN29.
[5] Massone, L.M., Polanco, P., Herrera, P., (2014). “Experimental and analytical response of RC wall boundary elements.” 10th U.S. National Conference on Earthquake Engineering, Anchorage, Alaska.
[6] Sritharan, S., Beyer, K., Henry, R.S., Chai, Y.H., Kowalsky, M., Bullf, D. (2014). “Understanding Poor Seismic Performance of Concrete Walls and Design Implications.” Earthquake Spectra, Vol. 30, Issue 1, pp. 307-334, doi:10.1193/021713EQS036M.
[7] Hoult, R.D., Goldsworthy, H.M., Lumantana, E. (2016) . Displacement capacity of lightly reinforced rectangular concrete walls.” Australian Earthquake Engineering Society 2016 Conference, Melbourne, Victoria.
[8] Lu, Y., Henry, R.S., Gultom, R., Ma, Q.T. (2017). “Cyclic testing of reinforced concrete walls with distributed minimum vertical reinforcement.” ASCE Journal of Structural Engineering, Vol. 143, Issue 5, doi:10.1061/(ASCE)ST.1943-541X.0001723.
[9] NZS 3101 (2006 ). “Concrete structures standard (Amendment 3).” Wellington, New Zealand.
[10] Paulay, T., Priestley, M.J.N. (1992). “Seismic design of reinforced concrete and masonry building.” John Wiley and Sons, 744 p., doi:10.1002/9780470172841.
[11] Rosso, A., Jimenez-Roa, L.A., Almeida, J.P., Blando, C.A., Bonett, R.L., Beyer, K. (2018). “Cyclic tensile-compressive tests on thin concrete boundary elements with a single layer of reinforcement prone to out-of-plane instability.” Bulletin of Earthquake Engineering, Vol. 16, Issue 2, pp. 859-887, doi:10.1007/s10518-017-0228-1.
[12] Haro, A.G., Kowalsky, M., Chai, Y.H., Luciera, G.W. (2018). “Boundary Elements of Special Reinforced Concrete Walls Tested under Different Loading Paths.” Earthquake Spectra, Vol. 34, Issue 3, pp. 1267-1288, doi:10.1193/081617EQS160M.
[13] Kawashima, K., Hosoiri, K., Shoji, G., Sakai, J. (2001). “Effects of Un-Bonding of Main Reinforcements at Plastic Hinge Region on Enhanced Ductility of Reinforced Concrete Bridge Columns.” Structural and Earthquake Engineering. Proceedings of Japan Society of Civil Engineering, 689 (I-57), pp. 45-64, doi:10.2208/jscej.2001.689_45.
[14] Mashal, M., Palermo, A. (2019). “Emulative Seismic Resistant Technology for Accelerated Bridge Construction.” Elsevier Journal of Soils Dynamics and Earthquake Engineering, Special Issue on Earthquake Resilient Buildings, 120, doi:10.1016/j.soildyn.2018.12.016.
[15] Nikoukalam, M. T., Sideris, P. (2016). “Experimental Performance Assessment of Nearly Full-Scale Reinforced Concrete Columns with Partially Debonded Longitudinal Reinforcement.” ASCE Journal of Structural Engineering, Vol. 143, Issue 4, doi:10.1061/(ASCE)ST.1943-541X.0001708.
[16] Patel, V.J., , Van, B.C., Henry, R.S., Clifton, G.C. (2015). “Effect of reinforcing steel bond on the cracking behavior of lightly reinforced concrete members.” Construction and Building Materials, Vol. 96, Issue 2, pp. 238–247, doi:10.1016/j.conbuildmat.2015.08.014.
[17] Priestley M. J. N., Park R. (1987). “Strength and ductility of concrete bridge columns under seismic loading.” ACI Structural Journal, Vol. 84, Issue 1, pp. 61-76.
[18] Berry, M., Lehman D. E., Lowes L. N. (2008). “Lumped-Plasticity Models for Performance Simulation of Bridge Columns.” ACI Structural Journal, Vol. 105, Issue 3, pp. 270-279.
[19] Naderpour, H., P. Fakharian. P. (2016). “A synthesis of peak picking method and wavelet packet transform for structural equation: Modal identification.” KSCE Journal of Civil Engineering, Vol. 20, Issue 7, pp. 2859–2867, doi:10.1007/s12205-016-0523-4.
[20] Jahangir H., Esfahani M.R. (2012). “Structural Damage Identification Based on Modal Data and Wavelet Analysis.” 3rd National Conference on Earthquake Structure, Kerman, Iran.
[21] Seyedi S.R., Keyhani A., Jahangir H. (2015). “An Energy-Based Damage Detection Algorithm Based on Modal Data. 7th International Conference on Seismology Earthquake Engineering.” International Institute of Earthquake Engineering and Seismology (IIEES), pp. 335–336.
[23] Daneshvar, M.H., Gharighoran, A., Zareei, S.A., Karamodin, A. (2020). “Damage Detection of Bridge by Rayleigh-Ritz Method.” Journal of Rehabilitation in Civil Engineering Vol. 8, Issue 1, pp. 149-162.
[24] Kaklauskas, G., Sokolov, A., Ramanauskas, R., Jakubovskis, R., (2019). “Reinforcement Strains in Reinforced Concrete Tensile Members Recorded by Strain Gauges and FBG Sensors: Experimental and Numerical Analysis.” Sensors, Vol. 19, Issue 1, pp. 1-13, doi:10.3390/s19010200.
[25] Matsumoto, Y. (2009). “Study of the Residual Deformation Capacity of Plastically Strained.” Steel, Yokohama National University, Yokohama, Kanagawa, Japan, Taylor Francis Group, London, UK.
[26] Hilson, C.W., Segura, C.L., Wallace, J.W. (2014). “Experimental study of longitudinal reinforcement buckling in reinforced concrete structural wall boundary element.” Tenth U.S. National Conference on Earthquake Engineering: Frontiers of Earthquake Engineering, Anchorage, Alaska, doi:10.4231/D3CC0TT9C.
[27] Altheeb, A., Albidah, A., Lam, N.T.K., Wilson, J. (2013). “The development of strain penetration in lightly reinforced concrete shear walls.” Australian Earthquake Engineering Society 2013, Hobart, Tasmania.