PSI - Issue 64

11

Author name / Structural Integrity Procedia 00 (2019) 000–000

S. Kolemenoglu et al. / Procedia Structural Integrity 64 (2024) 857–868

867

5. Conclusions This study examines the effectiveness of repair for slightly and moderately damaged RC columns that is implemented by using an environment-friendly structural repair mortar. For this purpose, four identical large-scale code-conforming columns were tested under constant axial load and lateral displacement reversals. Among these four columns, the reference column was tested to failure, while the remaining three were firstly tested to three different concrete damage levels (initiation of cover concrete crushing (damage level I), local cover crushing (damage level II), cover spalling (damage level III) and subsequently repaired without removing axial load for re-testing to failure. Based on the test results, the outcomes can be summarized as follows: - The performance of the specimen that was repaired after the initiation of crushing (R-27-1-1, damage level I) was satisfactory in terms of ductility and lateral strength. The stiffness of the repaired specimen was 90% of the reference specimen, while lateral strength and ductility were 96% and 140%, respectively. - The repair performance after local cover concrete crushing (R-27-1-2, damage level II) was also found to be satisfactory. The recovery ratios for stiffness and lateral strength were 0.91 and 0.93, respectively, while the ductility was almost completely recovered. - The performance of the specimen repaired after cover spalling (R-27-1-3, damage level III) was not as good as the damage level I and II specimens, particularly in the pulling direction. The recovery ratios for stiffness, lateral strength and ductility were 0.76 (push=0.84; pull=0.68), 0.77 (push=0.89; pull=0.68), 0.83 (push=no data; pull=0.83) respectively. - Overall, the environment-friendly structural repair mortar used for the repair of damage level I and II columns were found to be effective. However, for damage level III, which corresponds to a higher range of moderate damage, the column underperformed. It should be considered that the results and conclusions presented in this paper are specific to the geometry, material properties and the adopted loading system. Further experimental investigations are necessary for more generalized conclusions. Acknowledgements This study is supported by the Scientific and Technological Research Council of Turkey (TUBITAK) (1001, grant reference number 121M780). The authors kindly acknowledge Istanbul Aydın University for the various supports provided for conducting the experimental tests in this research. Also, the contributions from SIKA for repairing the specimens and Fibrobeton for the production of the specimens are thankfully acknowledged. The support from Bilal Sarı (PhD, ITU), Gönül Andırır (Bachelor, ITU), Emre Özkurt (Bachelor, ITU), Muhammet Mustafa Sayın (Bachelor, ITU), Kadir Can Çetin (Bachelor, ITU), Ali Serdar Uzuner (Bachelor, ITU) in the execution of the experimental test is also gratefully acknowledged. References ACI Committee. 2019. “Building Code Requirements for Structural Concrete (ACI 318-19)”, American Concrete Institute. ACI Committee. 2013. “Guide for Testing Reinforced Concrete Structural Elements under Slowly Applied Simulated Seismic Loads (ACI 374.2R-13)”, American Concrete Institute. ATC 145. (2021). Resilient Repair Guide Source Report: Post-Earthquake Assessment of Reinforced Concrete Buildings. Redwood City, California. Bedirhanoglu, I., A. Ilki, S. Pujol, N. Kumbasar, “Behavior of Deficient Joints with Plain Bars and Low-strength Concrete,” ACI Structural J., 107(3), 300-310, 2010. Bedirhanoglu, I., A. Ilki, T. Triantafillou, “Seismic behavior of repaired and externally FRP jacketed short columns built with extremely low strength concrete”, ASCE, Journal of Composites for Construction, 26(1), Feb, 2022. EN 12190 (1998). Products and systems for the protection and repair of concrete structures - Test methods - Determination of compressive strength of repair mortar