• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.227-230
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• 1998

The void ratio, continuous void ratio, coefficient of permeability, compressive strength and tensile strength were considered according to the EAF(Electric Arc Furnace) slag replacement and sand percentage in permeable concrete used with EAF slag as aggregate. The sand percentage was directly proportional to the permeable coefficient, but inversely proportional to the compressive strength. When the compressive strength and coefficient of permeability were 230 kg/$\textrm{cm}^2$ and 1$\times$$10^{-1}$ cm/sec, the useful sand percentage was 8%. When the EAF slag replacement was 25%, the coefficient of permeability was the most low and compressive strength was the most high.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.271-272
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• 2010

This thesis is researched to compare the shrinkage of lightweight concrete depending on depth to normal concrete. It is used artificial lightweight aggregate which has 20% of pre-absorb value by lightweight concrete. When water-binder ratio is 30%, average shrinkage of lightweight concrete section decreased than normal concrete, but differential shrinkage of lightweight concrete section increased. However water-binder ratio is 40%, average shrinkage and differential shrinkage of lightweight concrete section decreased than normal concrete.

• Computers and Concrete
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• v.21 no.1
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• pp.39-46
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• 2018

With the increase in industrialization and urbanization, growing demand has enhanced rate of new constructions and old demolitions. To avoid serious environmental impacts and hazards recycled concrete aggregates (RCA) is being adopted in all over the world. This paper investigates successive recycled coarse aggregates (SRCA) in which old concrete made with RCA in form of concrete cubes was used. The cubes were crushed to prepare new concrete using aggregates from crushing of old concrete, used as SRCA. The mechanical behavior of concrete was determined containing SRCA; the properties of SRCA were evaluated and then compared with natural aggregates (NA). Replacement of NA with SRCA in ratio upto 100% by weight was studied for workability, mechanical properties and microstructural analysis. It was observed that with the increase in replacement ratio workability and compressive strength decreased but in acceptable limits so SRCA can be used in low strength concretes rather than high strength concrete structures.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.253-256
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• 2000

The functions of porous concrete were influenced by continuous void, and it differ greatly from the distribution and size shape of continuous void in the same void volume. And porous concrete has been few used because the strength level of porous concrete is lower than that of ordinary concrete at the present time. So the purpose of this study is to increase the strength of porous concrete at the range of satisfying its function, analyze those effects of the mixing ratio of aggregate, affecting the development of its strength.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.30-31
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• 2016

Recently in the construction site is required various performance of mortar to deal with reliability, economy. Especially of environment-friendly, saving resources and high performance of mortar it began to require improvement of performance. Therefore, in this study, a series of tests was designed to develop a using mud flat mortar in view of the high absorption rate of tidal flats, to fix the water cement ratio to 70%. The mixing ratio were 10:0, 9:1, 8:2, 7:3, 6:4, 5:5, 4:6 of fine aggregate and mud flats. Compared the flow value, chloride content, compressive strength, tensile strength, and workability of fine aggregate the substituted mud flat mortar and basic cement mortar, present the basic data on the characteristics and effects of mud flat mortar.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.71-72
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• 2017

The oyster shell is lightweight and exhibits strength characteristics similar to sand. In this study, mortar specimens were fabricated by crushing them and processed to 5mm or less of the fine aggregate standard, and examined the fire resistance of the mortar according to changes in particle size distribution. In this experiment, seven particle size distribution conditions were tested. In addition, the mixing ratio was fixed at 1: 3, and the experiment was conducted in terms of the volume ratio because the densities of sand and oyster shells were different.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.153-159
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• 1996

The concrete with continuous voids (No Fine Concrete ; NFC) is the new planting material which may be used for stabilizing the sandy slope of river or road sides. The components of NFC are mainly coarse aggregate and low alkali cement paste, so to speak fine aggregate is not used. This report shows the fundamental properties of NFC, such as continous void ratio, compressive strength, permeability. As experimental results we can get the good quality of NFC, that is about 28% continuous void ratio, about 120kg/$\textrm{cm}^2$ compressive strength and high flowable permeability. And also planting grass and garden portulaca on the concrete with continuous voids is resulted in success.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.3
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• pp.177-184
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• 2000

The purpose of this study is to evaluate the performance of a new viscosity modifying admixture for concrete agent. For this purpose, selected test variables were the ratio of water to cement, the ratio of cement to fine aggregate, contents of superplasticizer, contents of viscosity modifying admixture. As a result of this study, it has been found that addition of viscosity modifying admixture to mortar modfies its fluidity and reduces its segregation by increasing the mortar viscosity. And it has been found that a new viscosity modifying admixture do not significantly affect the setting time, air content of mortar.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.5
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• pp.45-54
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• 2014

This study was performed to evaluate compressive strength, flexural strength, static modulus of elasticity, stress-strain ratio and durability of abrasion on EVA concrete reinforced steel fiber (SF) in order to use hydraulic structures, underground utilities, offshore structures and structures being applied soil contaminated area. It is used ordinary portland cement, crushed coarse aggregate, nature fine aggregate, EVA redispersible polymer powder, superplasticizer and deforming agent to find optimum mix design of EVA concrete reinforced steel fiber. EVA concrete reinforced SF was effected on the improvement of mechanical properties and durability of abrasion.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.912-915
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• 1998

As a fundamental study on the development of porous concrete for planting, this study is designed to present the properties of porous concrete by varying the kinds of cement, paste to aggregate ratio and dosage of AE admixture. As the results of experiment, the void volumes show 30~33%, 25~ 28% and 17~22% respectively, with paste to aggregate ratio of 20%, 30% and 40%. And unit weight is 1700~1900kg/㎥ while compressive strengths 40~60, 8 0~100 and 120~150kg/$\textrm{cm}^2$. pH of concrete shows a sufficient value at which the plant could grow, when the concrete is permeated in Ammonium Phosphate Dibasic for more than 1 hour. In brief, it shows a possibility of development of porous concrete if the concrete is permeated with permeating in Ammonium Phosphate Dibasic for more than 1 hour when the blast furnace slag cement is used.