• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.274-278
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• 1999

Determination of soil texture, particularly the clay fraction, is an important measurement in most researches related with soil. In this study micro-pipette method For soil particle size analysis was compared with the standard hydrometer method. Micro-pipette method can eliminate the need for bulky laboratory equipment and long settling times associated with the standard hydrometer or pipette method. In the results of this investigation, the particle size data obtained with micro-pipette method were in good agreement with those found using standard hydrometer method. And with this method one person could run analysis much larger numbers of soil sample per day than with hydrometer method in relatively small laboratory space.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.6
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• pp.29-34
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• 2018

In this research, regarding the cement supplied to ready mixed concrete plant, the feasibility of rapid acquisition test for cement fineness using hydrometer which used for early strength evaluation of concrete was analyzed. Additionally, regarding the rapid test with hydrometer control factors were provided. As a result of analysis, quality control using hydrometer was possible with the regressive equation obtained in five minute between density of suspension and fineness of cement powder. As the control factors, dispersing admixture, replacing kerosene as a medium, and temperature of cement and water were evaluated. According to the control factor evaluation, the tap water was optimum as a medium and calibration of keeping the temperature of water to $20^{\circ}C$ or correction factor was needed for density results. Finally, it is considered that the suggested rapid quality evaluation method using hydrometer is cheaper and easier method than currently used Blaine test.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.4
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• pp.325-329
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• 1984

This study was conducted to evaluate the performance of a miniaturized hydrometer of clay content determination in the field. The performance of the miniaturized hydrometer was compared to that of 152H hydrometer and pipette methods. Statistical analysis of the results showed the possibility of using the miniaturized hydrometer for clay content determination in the field.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.1
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• pp.43-49
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• 2018

The aim of the research is to analyze the feasibility of rapid quality evaluation method for blast furnace slag using hydrometer based on the former research of the prediction method for concrete compressive strength using hydrometer. Using this method, it is expected to provide a new application for blast furnace slag quality evaluation easily and rapidly during the receiving inspection. According to the experimental results, the settling time period of hydrometer was delayed with increased fineness of blast furnace slag. By using the regression equation of y = 198 120 x - 193 936(R=0.9398) obtained from the correlation between density of suspension at three minutes and fineness, it was possible to evaluate the quality of blast furnace slag fineness rapidly. Therefore, for ready-mixed concrete receiving inspection, the suggested method can be used as a cheap, a simple, and a rapid inspection method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.85-86
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• 2018

In this study, we previously conducted a quick evaluation of cement powder map using mesiline and hydrometer. The experiment also confirmed the possibility of rapid quality evaluation of cement powder. In this study, further studies have been conducted to apply speed and cost more economical than conventional methods, and the possibility of applying this research is to be analyzed. The result of the experiment was 500 mL of a bottled water bottle with a solid edge for measurement convenience, and the hydrometer was determined to be B type. In addition, density values of each other by powder during the same time period are considered to be measurable, indicating large differences.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.20-21
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• 2017

There have been reports in the media about some refineries that omit the refining process and deliver raw material for reasons of cost reduction, shortening of production time, etc. Also, in most RMC factories acceptance inspection is not conducted on account of issues with the proficiency of the equipment and cost issues; instead only scores are relied upon. Therefore this study sought to analyze the relation between the value of the density of FA actually delivered to RMC companies, attained with the Hydrometer method, and its fineness, to see whether the quality of FA can be evaluated statistically. Results led to the conclusion that there is a problem in terms of credibility in the fineness of FA shown on the test report. Upon analyzing the difference between the fineness of FA as measured using Blaine's air permeability method and its density of the Hydrometer method, the correlation was found to be satisfactory; therefore the possibility of a FA fineness quality evaluation could be proved as well.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.226-227
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• 2017

Basic lot tests via textile and visual examinations are conducted on FA carried into in-service RMCs. The system of evaluating quality by taking samples from each lot and examining them, or evaluating quality based on the score reports submitted by the deliverer during in-service training have on some instances been called into doubt as to their reliability in evaluating the quality of FA. Therefore this study sought to measure the density value of FA that is actually delivered to RMC companies according to the Hydrometer method and analyze its correlation to its test scores, to in turn analyze the reliability of the test reports and the characteristics of the quality of FA. The results led to the conclusion that the fineness and density marked on the score reports were problematic, and therefore accurate experiments and adjustment of significant digits on the test report are necessary.

• Journal of the Korea Institute of Building Construction
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• v.17 no.2
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• pp.119-125
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• 2017

Due to the processing cost, there were some reports on distribution of unrefined fly ash. Hence, in this research, the possibility of fly ash quality evaluation by measuring the density of various qualities of coal ash suspensions with hydrometer. According to the experimental results, the appropriate test conditions were determined with 1,000cc capacity mass cylinder for 1,000cc of water with 100g of fly ash. From the evaluating performance of various coal ashes, based on a good correlation between fineness and quality of the coal ashes, it was possible to evaluate the quality of coal ash by measuring different density of suspension with hydrometer. In this research conditions, the suggestable measuring time of density variation was three minute for fly ash quality related with fineness.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.167-168
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• 2017

In this research, the blast-furnace slag powder using the hydrometer also attempted to analysis the influence factor due to the temperature change of water and sample, and the number of upside down turns at the time of rapid evaluation. As a result, the influence of the number of turn was not large, but was the temperature of the water and sample are greatly affected.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.169-170
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• 2017

Recently in the construction industry there has been an increasing use of increasing replacement of cement with blast furnace slag cement(BS), an industrial by-product, to reduce environment load and production costs, and other increasing uses of BS cement. However in the case of BS being delivered in RMC factories, only score reports submitted when the are delivered are relied upon and ways to test the quality of fineness is inadequate. Therefore this study gave many changes to various cements and BS fineness to test the variations of BS as a cement, then used the correlation between this and the density value in the Hydrometer method to test the possibility for rapid appraisal of quality fineness of BS cement. Results showed that if the one fifth graph of the density and fineness correlation were to be used, a rapid appraisal of BS cement fineness quality would be possible.