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Title |
Setting Time Evaluation of Concrete Using Electrical Resistivity Measurement
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Authors |
이한주(Han Ju Lee) ; 임홍재(Hong Jae Yim) |
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DOI |
https://doi.org/10.4334/JKCI.2017.29.4.361 |
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Keywords |
concrete ; mix-proportion ; setting time ; electrical resistivity ; penetration resistance method |
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Abstract |
Setting time of cement-based materials can represent a developing strength in early-age mixture, and it can be used a significant parameter of high-performance concrete having various mix-proportions. Generally, initial and final setting time of concrete is measured by penetration resistance method that used a wet-sieving mortar mixture, therefore, it hardly represents the setting time of sound concrete including coarse aggregate. Recently, several nondestructive methods, such as ultrasonic velocity and impendence measurement, are proposed to evaluate the setting time of fresh concrete. This study attempts to measure an electrical resistivity using four-electrode method for evaluation of setting time in early-age cement-based materials. For this purpose, total 10 mixtures are prepared as different mix-proportions including chemical admixture. Based on the experimental results, two electrical parameters, such as initial electrical resistivity and rising time, are proposed to reflect a microstructure development by hydration of cement-based materials. As a result, proposed parameter is also discussed with the measured setting time by penetration resistance method.
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