• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.46-47
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• 2013

This study investigates the effect of a grading of aggregate on the properties of concrete. It is a common sense in Korea that the production of coarse aggregate in ready mixed concrete industry excludes particular aggregate size ranged from 5 mm to 13 mm for saving the production cost. This causes a gap grading of the aggregate for concrete, which can lead to the increase of unit water, the development of drying shrinkage-induced crack and the reduction of compressive strength. In this study, conventional aggregate obtained from a ready mixed concrete factory and the aggregate with a modified grading produced in lab. condition were prepared. Results showed that a good grading of aggregate (i.e., the ratio of 5~13 mm and 13~25 mm is 6 to 4) produced in the lab. condition significantly improved the slump and the compressive strength of the concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.213-216
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• 2004

Aggregate occupies about 70 to 80 percent by volume in concrete as skeleton of concrete, but recently, it has been insufficient in quantity to collect good natural aggregate because of exhaustion of aggregate resources. In case of Korea, in 2002, the using ratio of crushed stone occupies about $97\%$ of whole coarse aggregate, and ratio of crushed sand occupies about $18.3\%$ of whole fine aggregate. This is an experimental study to compare and analyze the properties of concrete according to the grading of crushed stone to improve quality and mix design of concrete using crushed stone. According to results, it was found that grading level of crushed stone in the range of G42 to G60 was better than any other grading level in terms of fluidity and compressive strength. And it is considered to be in the range of 6.52 to 6.85 in terms of FM.

• Clean Technology
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• v.8 no.3
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• pp.129-139
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• 2002

This is the study for recycling waste foundry sand. Authors studied about main subject of grading of aggregate and three experimental items such as physical properties of waste foundry sand, optimum grading for concrete products of low water ratio, and quality variations of concrete products according to substitution proportion of fine aggregate as waste foundry sand. We were convinced of following results by experimental study. The first was that waste foundry sand was not fit as the aggregate for concrete because of bad qualities such as grading, unit weight, solid volume and passing 0.08 mm seive, so it is proper to composition using with other fine aggregetes. The second was that optimum grading is fineness modulus of 2.77 to 3.28 And the last is that optimum condition about substitution proportion as waste foundry sand is 10% fine aggregate.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.373-378
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• 2000

The objective of this study was to investigate the influence the influence of theoretical void ratio(T.V.R), grading of aggregate and curing method on the strength and water permeability of porous concrete, and the reduction proportion of water permeability by these factors. The results of the study showed that its strength and water permeability were greatly depended on the T.V.R and grading of aggregate, but didn't on the curing method. And, when the T.V.R and grading of aggregate were increased, the reduction proportion of water permeability was small. As the relation ship between its physical properties and non-destruction test values was very high, its use for the estimation of the physical properties will be useful.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.138-139
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• 2014

In this study, conventional aggregate obtained from a ready mixed concrete factory and the aggregate with a modified grading produced in lab. condition were prepared. Results showed that a good grading of aggregate the ratio of 5~13 mm and 13~25 mm is 20~40 % produced in the lab. condition significantly improved the slump and the compressive strength of the concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.89-92
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• 2001

Because the grading of aggregate is major factor affecting on compressive strength and durability of concrete, the standard specification of concrete has proposed that the standard grading should be used to make ordinary concrete having good quality. But, it is not suitable for making product having low W/C because of difference between them in manufacturing processes and demanded efficiencies. This study investigated if the grading of the fine aggregate affects on tamping efficiency and compressive strength of concrete-based product. The results of this study showed that the suitable grading for making concrete-based product ranged from C type(FM:2.77) to D type(FM:3.38).

• Proceedings of the Korean Institute of Building Construction Conference
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• v.y2004m10
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• pp.55-58
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• 2004

This paper investigated the results of quality of concrete using mixed sand with grading adjustment in order to find out the applicability of fine aggregate with bad grading, According to test results, fluidity of concrete with fine level grading river sand was decreased while with coarse level grading crushed sand increased compared with that with medium level grading crushed sand. Use of mixed sand with grading adjustment(MSG) resulted in an improvement in fluidity. Increase in fineness modulus led to an increase in bleeding, For compressive strength, use of MSG increased compressive strength. For drying shrinkage, use of fine level grading river sand resulted in an increasing drying shrinkage due to the larger presence of fine particles, while use of MSG led to a reduction in drying shrinkage

• Proceedings of the Korea Concrete Institute Conference
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• 1991.04a
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• pp.33-36
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• 1991

This study is designed for analyzing the properties of water-proofing on cement mortar according to the using ethylene vinyle acetate emulsion, and the fine aggregate grading such as uniform, gab and continuosly grading. And is aimed for presenting the reference data on the practical use.

• Proceedings of the Korea Concrete Institute Conference
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• 1991.10a
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• pp.26-29
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• 1991

This study is designed for analyzing the properties of water-proofing on concrete according to the using EVA(ethylene vinyle acetate) emulsion, and the fine aggregate grading such as uniform, gap and continuously grading. And is aimed for presenting the reference data on the practical use.

• Computers and Concrete
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• v.26 no.6
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• pp.505-513
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• 2020

Grading of aggregate influences significantly almost all of the concrete performances. The purpose of this paper is to propose practicable equations that express the optimized total aggregate gradation, by weight or by number of particles in a concrete mix. The principle is based on the fractal feature of the grading of combined aggregate in a solid skeleton of concrete. Therefore, equations are derived based on the so-called fractal dimension of the grain size distribution of aggregates. Obtained model was then applied in such a way a correlation between some properties of the dry concrete mix and the fractal dimension of the aggregate gradation has been built. This demonstrates that the parameter fractal dimension is an efficacious tool to establish a unified model to study the solid phase of concrete in order to design aggregate gradation to meet certain requirements or even to predict some characteristics of the dry concrete mixture.