• International Journal of Concrete Structures and Materials
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• v.18 no.2E
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• pp.117-124
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• 2006

Porous concrete has been used recently for the purpose of decreasing the load on the earth environment. It consists solely of cement, water and coarse aggregate of uni form size. Its fundamental properties are considerably affected by the physical properties of aggregate because the aggregate is the main material for the most part in its mix proportion. Because of this reason, this study carried out an investigation of the influence of the size and type of aggregate on the fundamental properties of porous concrete. It is shown that the fundamental properties of porous concrete was seldom affected by the size of aggregate except for the case of using $2.5{\sim}5mm$ aggregate but varied significantly by the type of aggregate. In particular, the compressive strength of porous concrete using $2.5{\sim}5mm$ aggregate was much higher than that using other aggregate, and its void ratio and coefficient of permeability was lower. Moreover, the capacity to maintain the permeability of porous concrete was found to vary by the size and type of aggregate. Of particular notice was that it decreased greatly when $2.5{\sim}5mm$ aggregate was used. Unlike ordinary concrete, porous concrete exhibited very high dynamic modulus of elasticity at early age and continued to increase but slowly afterwards.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.495-500
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• 2001

In this study, it was analized and examined fundamental properties of Electric Pole Recycled Aggregate(EPRA) and hardened properties & chemical resistance with H$_2$SO$_4$by replacement ratios of EPRA, and the results are as follows 1) In the case of electric pole recycled coarse aggregate, All fundamental properties are better than that of normal recycled aggregate and both water absorption and amount of crushed loss are with level of natural aggregate 2) As the replacement ratio of electric pole recycled fine aggregate is increased strength development is decreased. but in the case of coarse aggregate, that of it is with level of natural aggregate 3) As the replacement ratio of electric pole recycled fine aggregate is increased chemical resistance is decreased. but in the case of coarse aggregate, that of it is with level of natural aggregate

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.33-38
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• 1997

The reuse of waste concrete amy settle the problems of environmental pollution and critical shortage of good natural aggregate. But recycled aggregate particles consist of substantial amount of relatively soft cement paste component. These aggregates are more porous, and les resistant to mechanical actions than natural aggregate. And the source of supply for manufacturing recycled aggregate is generally composed of different types of original aggregate and strengths of original mortar. The properties of recycled aggregate exhibit a considerable variation due to the properties of original concrete. This paper is an experimental study on the fundamental properties of recycled aggregates sampled from processing plant in the suburbs of TaeJeon.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.153-156
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• 2006

This study investigated influence of kind of fine aggregate on fundamental properties of concrete. For the properties of fluidity with various type of fine aggregate, lime stone crushed fine aggregate(Ls) exhibited favorable result, due to grain shape and particle distribution, and next was granite crushed fine aggregate(Gs), natural fine aggregate(Ns). Ns had the highest value of air content while Ls had the lowest, due to the effective filling performance by continuos particle distribution. Ls, Ns, Gs in an order had higher bleeding capacity and faster setting time. However, compressive and tensile strength value exhibited similar tendency, regardless of aggregate type.

• International Journal of Highway Engineering
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• v.18 no.6
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• pp.105-113
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• 2016

OBJECTIVES : This study is to develop the optimum mixing proportions for cement concrete pavement with using recycled aggregates. METHODS : The mixture varied recycled coarse aggregates content from 50 % to 100 % to replace the natural coarse aggregates by weight. Tests for fundamental properties as a cement concrete pavement were conducted before and after hardening of the concrete. RESULTS : It was found that the variation in the amount of the recycled aggregate affected the compressive and flexural strength development, as well as the chloride ion penetration resistance. As the amount of the recycled aggregate content increased the compressive and flexural strength and the resistance to chloride ion penetration decreased. However, the resistance to freeze-thaw reaction was affected significantly. In addition, the gradation of the aggregate became worse and hence so did the coarseness factor as the recycled aggregate amount increased. CONCLUSIONS : The fundamental properties of the concrete with recycled aggregate does not seem to be appropriate when the recycled aggregate quality is not guaranteed up to a some level and its replacement ratio is over 50%. The optimized gradation of the aggregates should also be sought when the recycled aggregate is used for the cement concrete pavement materials.

• Proceedings of the Korea Concrete Institute Conference
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• 1993.04a
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• pp.26-29
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• 1993

To analyze the using of recycled aggregate on concrete as the substitude aggregate is important problem for the reuse of waste matter and prevention of environmental pollution. Therefore, this study is designed for investigating and analyzing the mechanical properties and early estimational properties of strength on concrete using aggregate of the waste concrete. And is aimed to provide the fundamental data for recycled aggregate.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10c
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• pp.72-75
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• 1998

In this study, we investigate the difference of concrete between natural aggregate and electric are furnace(EAF) slag one in oder to use EAF slag aggregate as coarse aggregate in concrete. We find the physical and chemical properties of EAF slag aggregate for the aging process. We consider the properties od the concrete made with EAF slag aggregate which are compressive strength, splitting tensile strength and modulus of elasticity.

• Journal of the Korea Concrete Institute
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• v.13 no.5
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• pp.438-446
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• 2001

Recently, porous concrete has been used for the purpose of decreasing the load of earth environment. It consists solely of cement, water and uniform-sized coarse aggregate. And its fundamental properties will be considerably affected by the physical properties of aggregate because the aggregate occupies for the most part in its mix proportion. For such a reason, this study was carried out to investigate the influence of the sizes and kinds of aggregate for the fundamental properties of porous concrete. It showed that the fundamental properties of porous concrete were the similar value in all sizes of aggregate except in the case of using the 2.5∼5㎜ aggregate and were varied according to the kinds of aggregate. In particular, compressive strength of porous concrete using 2.5∼5㎜ aggregate was more higher than that using other aggregate, and its void ratio and coefficient of permeability was lower. And the maintenance capacity of permeability of porous concrete was varied by the sizes and the kinds of aggregate. In particular, it was greatly decreased in case of using the 2.5∼5㎜ aggregate. And unlike dynamic modulus of elasticity of ordinary concrete, that of porous concrete was very high value in early ages and was slowly increased after that time.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.635-640
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• 2001

Recently, it has been processed to study about recycled aggregate but a study about using of recycled powder is producted when manufacturing recycled aggregate has not been acted. So in this study on the fundamental properties and application as cementious admixture by heating temperature for mortar properties of recycled powder and sand is obtained like following results. It is judged that application of recycled powder of heat treatment on $600^{\circ}C$ and cement replacement ratio below 10% is available.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.213-214
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• 2011

This study investigates the fundamental properties of bast furnace-based mortar made with recycled fine aggregate. Results showed that increasing recycled fine aggregate accelerated setting time, proportionally increased the compressive and flexural strength of mortar specimens. However, it is concluded that for quality and cost effectiveness, the optimum content of this recycled fine aggregate in mortar was found to be 80%.