Confinement of Reinforced-Concrete Columns with NonCode Compliant Confining Reinforcement plus Supplemental Pen-Binder
Abstract. One of the important requirements for earthquake resistant building related to confinement is the use of seismic hooks in the hoop or confining reinforcement of reinforced-concrete column elements. However, installation of a confining reinforcement with a 135-degree hook is not easy. Therefore, in practice, many construction workers apply a confining reinforcement with a 90-degree hook (non-code compliant). Based on research and records of recent earthquakes in Indonesia, the use of a non-code compliant confining reinforcement for concrete columns produces structures with poor seismic performance. This paper presents a study that introduces an additional element that is expected to improve the effectiveness of concrete columns confined with a non-code compliant confining reinforcement. The additional element, named a pen-binder, is used to keep the non-code compliant confining reinforcement in place. The effectiveness of this element under pure axial concentric loading was investigatedcomprehensively.The specimens tested in this study were 18 concrete columns,with a cross-section of 170 mm x 170 mm and a height of 480 mm. The main test variables were the material type of the pen-binder, the angle of the hook, and the confining reinforcement configuration.The test results indicate that adding pen -binders can effectively improve the strength and ductility of the column specimens confined with a non-code compliant confining reinforcement.
Purwono, R., Tavio, Imran, I. & Raka, I.G.P., Tata Cara Perhitungan Struktur Beton Untuk Bangunan Gedung (SNI 03-2847-2002), ITS Press, Surabaya, Indonesia, 2006
Imran, I., Suarjana, M., Hoedajanto, D., Soemardi, B. & Abduh, M., Beberapa Pelajaran dari Gempa Yogyakarta; Tinjauan Kinerja Struktur Bangunan Gedung, Jurnal HAKI (ISSN No. 0216/5457), 7(1), pp. 1-13, 2006.
Imran, I., The 6 March 2007 West Sumatera Earthquake-Lesson Learned and Recommendations, The International Symposium on Disaster in Indonesia (ISDI): Problem and Solution, Padang, 26-28 Juli, 2007.
Imran, I., Hoedajanto, D. & Suharwanto, Beberapa Pelajaran dari Gempa Aceh; Tinjauan Kinerja Dua Bangunan Perkantoran di Banda Aceh, Prosiding Seminar Gempa HAKI 2005 (ISBN 979 -98441-2-6), 25 Mei, Jakarta, 2005.
Sheikh, S.A. & Yeh, C., Tied Concrete Columns under Axial Load and Flexure, Journal of Structural Engineering, ASCE, 116(10), pp. 2780-2800, Oct. 1990.
Saatcioglu, M. & Razvi, S.R., Strength and Ductility of Confined Concrete, ASCE Journal of Structural Engineering, 118(6), pp. 1590-1607, June 1992.
Wehbe, N.I., Saiidi, M.S. & Sanders, D.H., Seismic Performance of Rectangular Bridge Columns with Moderate Confinement, ACI Structural Journal, 96(2), pp. 248-258, Mar.-Apr. 1999.
Richart, F.E., Brandtzaeg, A. & Brown, R.L., The Failure of Plain and Spirally Reinforced Concrete in Compression, Bulletin No. 190, Univ. of Illinois Engineering Experiment Station, Urbana, Illinois, 1929.
Sheikh, S.A. & Khoury, S.S., A Performance Based Approach for The Design of Confining Steel In Tied Column, ACI Structural Journal, 94(4), pp. 421-431, Jul-Aug. 1997.
Paultre, P. & Legeron F, Confinement Reinforcement Design for Reinforced Concrete Columns, ASCE Journal of Structural Engineering, 134(5), pp. 738-749, May 2008.
Lukkunaprasit, P. & Sittipunt, C., Ductility Enhancement of Moderately Confined Concrete Tied Column with Hook Clips, ACI Structural Journal, 100(4), pp. 422-429, July-August 2003.
Sheikh, S.A. & Uzumeri, S.M., Strength and Ductility of Tied Concrete Column, Proceedings, ASCE, 106(5), pp. 1079-1102, May 1980.
Mander, J.B., Priestley, M.J.N. & Park, R., Theoritical Stress-Strain Model for Confined Concrete, ASCE Journal of Structural Engineering, 114(8), Aug. 1988