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Volume 6, Number 4, October 2021 , pages 319-327 DOI: https://doi.org/10.12989/acd.2021.6.4.319 |
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Experimental study on bolt torque–tension relationship for different washer and nut combinations |
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Seung-Hyeon Hwang, Sanghee Kim and Keun-Hyeok Yang
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| Abstract | ||
| This experimental study was conducted to determine nut factors based on four combinations of washers and nuts. A prestressing force was applied to a long reinforcing bar using the torque–tension method. All the sets exhibited a linear trend. The nut factors for combinations of the flat washers and hex nuts, spring washers and hex nuts, flat washers and heat-treated nuts, and flat washers and self-locking nuts were 0.228, 0.224, 0.299, and 0.397, respectively. Additionally, the relaxation of the flat washers and hex nuts in a relatively long-term period (40 days in this study) was evaluated, and eight specimens subjected to various initial prestressing forces were analyzed. The average change in prestressing force was -3.98%. It is necessary to consider prestressing force loss for relatively long-term when prestressing force is applied to a long reinforcing bar. | ||
| Key Words | ||
| nut factor, prestressing force, relatively long-term relaxation; torque–tension, washer and nut | ||
| Address | ||
| Seung-Hyeon Hwang:Department of Architectural Engineering, Kyonggi University, 154-42 Gwanggyosan-ro, Youngtong-gu, Suwon, Kyonggi-Do, 16227, Republic of Korea Sanghee Kim:Department of Architectural Engineering, Kyonggi University, 154-42 Gwanggyosan-ro, Youngtong-gu, Suwon, Kyonggi-Do, 16227, Republic of Korea Keun-Hyeok Yang:Department of Architectural Engineering, Kyonggi University, 154-42 Gwanggyosan-ro, Youngtong-gu, Suwon, Kyonggi-Do, 16227, Republic of Korea | ||
