• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.358-366
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• 2019

The purpose of this study is to explore the possibility of estimating optimum surface finishing work time of the fresh concrete placed at the job site by applying a surface hardness test meter(Durometer). Tests are carried out by measuring and comparing the Proctor penetration resistance test and hardness test by Durometer. Correlations between Procter penetration test and hardness test by Durometer were obtained. Two different types Durometer were applied to estimate setting time. Test results indicate that the measurement of the Durometer and the test of the Proctor penetration resistance are highly correlated. When measuring the initial setting time with Durometer, initial setting time is reached when the hardness value by the type C Durometer is reached around 42HD, and when final setting is measured with the type D Durometer, the surface finishing work time limit and curing time can be estimated with 10HD of Durometer.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.33-38
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• 2020

The aim of the research is to evaluate the feasibility of durometer for assessing setting time of the concrete by comparing it with the currently used proctor penetration test method to improve the surface finishing timing determining method generally determined based on the experience of the worker. As a research result, the correlation between suggesting method using durometer with currently used proctor penetration test method was high enough. Hence, on the surface of the concrete, the initial setting time and the final setting time could be designated as 41 HD with C-type, and 11 HD with D-type, respectively. Therefore, the durometer can be used as a portable setting time evaluation device with the easiness of handling and measuring for determining concrete surface finishing timing quantitatively.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.116-117
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• 2019

In this research, Proctor insertion resistance test values and Durometer A type hardness values were compared and analyzed between the setting times of the concrete using CGS for Fine Aggregate, and the results are summarized as follows. 1) The Proctor penetration resistance test value and the hardness value of Durometer A type showed a high correlation in the form of a curve. 2) About surface finish The resolution exceeding the hardness value of the Durometer A type uses about 25 HD, and in the case of termination, about 35 HD, and is considered to be effective for determining the surface finishing work time. The possibility to do is expected.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.118-119
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• 2019

In this study, we compared the proctor penetration resistance test value of the concrete using CGS for Fine Aggregate and the hardness value of the Durometer. The results are summarized as follows. 1) Surface finish The Durometer C type setting time measurement value was about 45 HD, and the hardness value of the Durometer D type was about 5HD. 2) The proctor penetration resistance test value and the hardness value of the Durometer are highly correlated and are expected to be easy to use.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.81-82
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• 2019

In this study, the Proctor penetration resistance test value and the hardness value of the improved Durometer were compared and analyzed for the change in the FA replacement rate of the concrete using CGS fine aggregate. The results are summarized as follows. It is. 1) The Proctor penetration resistance test value and the hardness value of the improved Durometer showed a high correlation in the form of a curve. 2) About surface finish Super-resolution with the improved Durometer is considered to be useful when using about 50 HD and about 80 HD in the end to determine the surface finishing work time.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.9
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• pp.143-150
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• 2019

The purpose of this study was to propose how to determine the setting time related to the determination of the surface finish working time of the concrete using a Durometer, which is used as a rubber hardness meter. Two different types of Durometer were used to measure the setting time of the concrete. High flowing concrete with 40% of water to binder ratio was fabricated maintaining $600{\pm}100mm$ of slump flow. The test results indicated that the application of the Durometer resulted in a high correlation with the penetration resistance tester in both mortar and concrete. When measuring the setting time of the concrete, with properly used with Durometer, evaluation of the setting time of the concrete can be available. Therefore, it is thought that the measurement of the final set of the durometer C type can be useful to decide the limit time of the finishing operation and the time of the rejuvenation of the curing process by measuring the finishing set at 40 HD in the case of the initial set and 10 HD in the case of D type.