• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.2
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• pp.107-116
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• 2002

The amount used of aggregates for concrete is increasing rapidly since the mid-1980s in Korea. The natural gravels from river are already displaced with crushed stone, and use of crushed sand as a substitute of natural river sands, also, is getting increased day by day. This paper is presented fur analysis on mechanical properties of high strength concrete using fly ash and crushed sand. The material functions in mixing design of concretes are various water-cement ratios(w/c) such as 0.25, 0.40, 0.55 and different replacement ratio of crushed sand to natural sands such as 0%, 20%, 40%, 60%. As a results, it has been shown that compressive strengths of concretes with W/C lower than 0.40 and 0.25 are higher than 400 kgf/$\textrm{cm}^2$ and 600 kgf/$\textrm{cm}^2$ respectively. It is also concluded that the results of rapid chloride permeability tests of concrete are evaluated to negligible. The conclusions of this study is that it is possible to use fly ash and crushed sand fur high strength concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.263-266
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• 1999

This study aims to make high performance concrete for normal strength using crushed stone fines to control high strength of the high performance concrete. According to the experimental results, when crushed stone fines are increased every 10%, 15% of compressive strength is decreased, and 5% of drying shrinkage is increased, compared to normal high performance concrete. Also, high performance concrete has been evaluated to have good durability factor more than 100% in the 480cycle of freezing and thawing test, without regard to using AE and crushed stone fines.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.147-152
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• 1998

This study is to investigate the application of concrete with crushed sand on site. As a result, it is showed that the combined sand mixed with sea sand is very desirable for obtaining workability and strength of concrete, and the optimal replacement percentage of crushed sand is 50% with sea sand. After all, the crushed sand could be sufficiently used as a fine aggregate for concrete in the aspect of economical efficiency and quality, but the particle shape and microsand passing No.200 sieve should be firstly improved for increasing workability of concrete on site.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.497-500
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• 2006

In this paper, study on applicability and quality control of the concrete using crushed sand. Recently, Trouble of sand supply is occurred according to exhaustion of natural sand resources. Now, application of crushed sand are proposed for solution of trouble of sand supply. Therefore, this study evaluated properties of concrete using crushed sand which mixing rate and changing FM.

• Journal of Nutrition and Health
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• v.46 no.4
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• pp.382-390
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• 2013

This study was designed to investigate the amount of free sugar according to each beverage category in coffee and beverage stores. The groups were categorized as 15 groups based on the kind of beverage material. The beverage groups contributing to total sugar per 100 mL were milk + syrup or powder, hot (12.9 g), ade (12.6 g), milk + syrup or powder + crushed ice (11.9 g), and espresso shot + milk + syrup + crushed ice (11.4 g). The beverage groups contributing to free sugar per 100 mL were ade (12.6 g), milk + syrup or powder + crushed ice (10.8 g), espresso shot + milk + syrup + crushed ice (10.3 g), and milk + syrup or powder, hot (9.7 g). The beverage groups contributing to total sugar (energy) per portion size were milk + syrup or powder + crushed ice 56.6 g (332.3 kcal), espresso shot + milk + syrup + crushed ice 49.3 g (333.4 kcal), milk + syrup or powder, hot 46.3 g (372.1 kcal), and milk + syrup or powder, ice 38.1 g (325.9 kcal). The beverage groups contributing to free sugar per portion size were milk + syrup or powder + crushed ice 51.2 g, espresso shot + milk + syrup + crushed ice 44.9 g, ade 37.1 g, milk + syrup or powder, hot 34.6 g, and milk + syrup or powder, ice 30.1 g. The percent of average free sugar per portion size of the WHO recommendation (free sugars <10% of total energy; <50 g/2,000 kcal) was milk + syrup or powder + crushed ice 102.4%, espresso shot + milk + syrup + crushed ice 89.8%, ade 74.1%, and milk + syrup or powder, hot 69.2%. The proportion of beverage in excess of WHO recommendation per portion size was 14.6% in espresso shot + milk + syrup + crushed ice, 22.7% in ade, and 10.9% in milk + syrup or powder, hot. Therefore, in coffee and beverage stores, menu development with reduced sugar content is needed, and nutrition information should be provided through sugar nutrition labeling.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.2
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• pp.83-92
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• 2006

Recently, interest grew recently on the quality of aggregates following the diminution of primary resources from river and the growing construction demand which exhausted high-quality sand sources around large cities and incited the use of low grade aggregates like shore sand and sea sand that can be supplied in natural state. Especially, the environmental preservation concern and the augmentation of public grievance about the exploitation of sea sand as substitute to river sand are gradually impeding the supply. This situation aggravated by the recent interdiction to extract sea sand which resulted in sand crisis that even led once to the suspension of construction works. The lack of sea sand and river sand increased the exploitation of crushed sand which occupies now nearly 20% of the whole quantity of fine aggregates. And, the use of crushed sand may be expected to grow continuously in the future. This paper described that the properties of crushed sand and the concrete using the crushed sand, the technologies to improve quality of crushed sand and the concrete in order to provide information for the production of high-quality concrete using crushed sand.

• Journal of the Korea Institute of Building Construction
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• v.6 no.1 s.19
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• pp.101-107
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• 2006

While a Study with regard to the measurement on Concrete Strength and the Change of Drying Shrinkage in accordace with Content Ratio of Crushed Stone Powder, it is being analyzed as the result that the strength according to Content Ratio of crushed Stone Powder is somewhat lowering. Accordingly, it is the real situation that the Concrete mixed with Crushed Stone Powder is utilized for non-structural material, not for the structural material. Therefore, this Research willing to furnish the suitable utilizing scheme for construction site as well as practical life by means of conduct the experiment on both Concrete Pressure Strength according to mixture with Crushed Stone Powder and Elastic Modulus, it also presumes the optimum Elastic Modulus Equation after analysis of comparison with common concrete strength. As the result of the experiment, in case of the Content Ratio of Crushed Stone Powder is less than 5%, it did not display a big difference in its both strength and matter-property compare with common concrete. In case of Elastic Modulus, when the Pressure Strength is 50% and 40% respectively, the Elastic Modulus Equation accords very well with the provided condition of Quadratic function, and as the result of the Presumption on Elastic Modulus according to Content of Crushed Stone Powder, in case the Pressure Strength is 50%, Elastic Modulus Equation showed that Error Ratio of Cubic function is at degree of 0.0005%, in case the Pressure Strength is 40%, Elastic Modulus Equation was accorded well with the value of the experimental data likely as the Error Ratio of Cubic function is at the degree around 0.0034%, respectively.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.11a
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• pp.17-20
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• 2005

This study investigates mock-up test of the concrete containing crushed sands with improved quality and following could be draws as conclusions. The slump satisfies the target value. The air content reaches the goal, however, it decreases by the occurrence of loss with elagse of age. In normal strength region, the setting time of CS24 member is shorter than that of SS24 member. In high strength region, the setting time of SS50 member is make only slower than that of CS5O because of the use of retarding AE agent. The compressive strength of the concrete using crushed sands is little higher than the concrete using washed sea sands, and the compressive strength of core sample increases at lower part. Drying shrinkage of the concrete using crushed sands is larger than that using washed sea sands. At water caring condition, both the concrete using crushed sands and using washed sands expand at first, exhibit to be swelled and with elagse of age, they remain relatirely constant. Also, the drying shrinkage occurred greatly when the width and thickness of a member are small because it is easy to evaporate the inner part vapor in the small width and thickness of a member. there can be little different according to the location of a contact gauge, however it is similar to the change of specimen's length change. The concrete using crushed sands, of which grading, grain shape and fine particle is improved, are comparable to the quality of the concrete using washed sea sand.

• Journal of the Korean Society of Safety
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• v.16 no.1
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• pp.65-72
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• 2001

Portland cement concrete is made with coarse aggregate, fine aggregate, portland cement, water and, in some cases, selected chemical admixture such as air-entraining agents, water reducer, superplasticizer, and so on, and mineral admixture such as fly ash, silica fume, slags, etc. Typically, in the concrete, the coarse aggregate and fine aggregate will occupy approximately 80 percent of the total volume of the finished mixture. Therefore, the coarse and fine aggregates affect to the properties of the portland cement concrete. As the deposits of natural sands have slowly been depleted, it has become necessary and economical to produce crushed sand(manufactured fine aggregate). It is reported that crushed sand differs from natural sands in gradation, particle shape and texture, and that the content of micro fines in the crushed sand affect to the quality of the portland cement concrete. Therefore, the purpose of this paper is to investigate the characteristics of fresh and hardened concrete with higher micro fines. This study provides a firm data to apply crushed sand with higher micro fines.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.376-379
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• 2004

The objective of in this study makes investigation into the characteristics of concrete as to properties and blended ratio of crushed aggregates through experimental researches. In this study, river sand is blended with crushed sand as to investigate the quality change and characteristics of concrete with variation of blend ratio of crushed sand(50, 60, 70, 80, 90, $100\%$). Measured the air contents and slump to investigate properties of fresh concrete, and unit weight and compressive strength in age of 7, 28days to investigate properties of hardened concrete. The experimental results of crushed aggregates' qualities were all satisfied with Korea Standard's values.