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http://dx.doi.org/10.5762/KAIS.2018.19.1.92

Strength Evaluation of High-Strength Concrete Specimens within Reinforcing Bars  

Ko, Hune-Bum (Department of Architecture, Inha Technical College)
Publication Information
Journal of the Korea Academia-Industrial cooperation Society / v.19, no.1, 2018 , pp. 92-97 More about this Journal
Abstract
Recently, the safety issue of high-rise concrete buildings damaged by fire, helicopter collisions, earthquakes, and faulty construction has attracted a great deal of interest. It is essential to know the strength of the concrete in order to accurately evaluate its safety for the reinforcement of these buildings. The core drilling method is considered to be the most effective method of assessing the compressive strength of concrete. However, it is very difficult to retrieve the core without the reinforcing bars, because buildings made with high-strength concrete are overcrowded with reinforcing bars. These reinforcing bars are often present in the core specimens, but there are few research studies and no regulations concerning the assessment of the strength of the concrete for high-strength core specimens within reinforcing bars. The purpose of this study is to investigate the effects of the reinforcement arrangement on the strength of the concrete and to present the quantitative values. To complete this research, the compressive strengths of different types of concrete with two different strengths (40 MPa and 60 MPa), two reinforcing bar diameters (10 mm and 12 mm), and 15 types of specimens with or without reinforcement arrangements were prepared and tested. As a result, the strength of the cylinders whose volume is less than or equal to the reinforcement volume of $53.1cm^3$ (about 4 - 13 mm) was predicted to have a low value of up to 60% of the strength of the cylinders without reinforcement.
Keywords
Cylinder; Core; High-strength concrete; Reinforcing bar; Reinforcement arrangement;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
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1 H. Tamura, T. Ueda, "An experimental study on the compressive strength of concrete core within rebar(in Japanese)", Proceedings of the Architectural institute of Japan, pp. 127-128, Nov. 1980.
2 S. Otsuka, Y. Nakata, S. Oki, "Consideration of correction method for compressive strength of core specimen within deformed bar", The bulletin of institute of technologists, no. 4, pp. 53-60, Mar. 2013.
3 H. B. Ko, "Effect of the Embedded reinforcing bar of specimens on the compressive strength of concrete", Journal of the Korea academia- industrial cooperation society, vol. 17, no. 9, pp. 552-558, Sep. 2016. DOI: https://doi.org/10.5762/KAIS.2016.17.9.552   DOI
4 H. H. Jeong, U. J. Kim, G. Y. Ahn, S. R. Lee, " An experimental study on the compressive strength of concrete cylinders to ascertain the influence of reinforcement(in Korean)", Proceedings of Korean society of civil engineers, pp. 984-987, Oct. 2006.
5 S. W. Kim, "Influence of steel reinforcing bars on concrete compressive strength of cored specimen for structure measurement", Master thesis, Department of architecture engineering, Graduate school, Yensei university, Dec. 2010.
6 DIN 1048 Teil 2, "Testing concrete; testing of hardened concrete (specimens taken in situ)", 1991.
7 R. D. Gaynor, "Effect of Horizontal Reinforcing Steel on the Strength of Molded Cylinders," Journal of the American Concrete Institute, vol. 62, no. 7, pp. 837-840, 1965.
8 ASTM C42/C42M-04, "Standard Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete", 2004.
9 JIS A 1107:2012, "Method of sampling and testing for compressive strength of drilled cores of concrete", 2012.
10 BS EN 12504-1:2009, "Testing concrete in structures: Part 1:Cored specimens - Taking, examining and testing in compression", 2009
11 Korean agency for technology and standards, KS F 2422, "Method of obtaining and testing drilled cores and sawed beams of concrete", 2012.