• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.419-424
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• 2000

The primary objectives of this study are to investigate the properties of strength and durability of recycled aggregate concrete was added polypropylene as variables and to fabricate fine concrete in some conditions. The variables are substitution ratios of recycled aggregate(0, 30, 50, 100%) and additions of polypropylene(0, 0.2, 0.5, 1.0%). Compressive strength test to investigate strength properties and freeze-thawing test and drying shrinkage test to durability properties were done. As the result of this study, When variables are substitution ratio(30%) of recycled aggregated and addition(0.5%) of polypropylene, fine concrete was fabricated.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.273-274
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• 2018

When IGCC Slag(CGS) aggregate was used as PHC-Pile, the moldability was lowered as the mixing ratio increased. concrete mix design. Also the mix characteristics increased the use of AD depending on the usage rate, however, require detailed consideration.

• Journal of the Korean GEO-environmental Society
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• v.11 no.3
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• pp.33-41
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• 2010

The rammed aggregate compaction pile method is widely used as soft ground improvement method because of the installed piles improve not only overall composite capacity but also discharge capacity. But the discharge capacity is declined when the clogging is generated due to the clay penetration into voids of rammed aggregate compaction pile with the time elapsed. The purpose of this study is to reduce the clogging problem occurred in rammed aggregate compaction pile constructed in the soft ground and to minimize voids of rammed aggregate compaction pile. The proper mixing ratio was determined which is based on the results of the large scale direct shear tests conducted to get strength and permeability as optimum mixing ratio of crushed stone and bottom ash. The test results indicated that the highest internal friction angle was obtained at 80:20 mixing ratio of crushed stone and bottom ash. The internal friction angle was declined when the mixing ratio of the bottom ash increased over 20%. The results of the clogging tests, presented that the mixture of 80:20 crushed stone and bottom ash is highest effective of clogging than ratio of pure crushed stone.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.631-636
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• 2002

This study shows basic data for using as the structural lightweight aggregate. This will be the procedural method of recycling environmental close waste PET bottle lightweight aggregate(PBLA) that is rapidly increased the amount of production of waste PET bottle recently, the quality of developed PBLA and the fundamental properties by analyzing of mortar containing with PBLA. After experiment, the result shows the PBLA quality that have oven dry specific gravity of 1.39, unit volume weight of 844 kg/m$^3$ and absorption rate of 0% is satisfied with qualify regulation of lightweight aggregate. The flowability of mortar containing PBLA is increased maximum 16% with increasing mixing ratio of PBLA, however the compressive strength of mortar is decreased maximum 35% with increasing mixing ratio of PBLA.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.655-660
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• 2002

The purpose of this study is to analyze void ratio, coefficient of water permeability, and strength characteristics when silica fume and carbon fibers were added in order to improve the strength of porous concrete, and when recycled aggregates were used. Comparing with the case that recycled aggregate was not used, as the replacement ratio of recycled aggregate increased, the differences in void ratios and strength characteristics were decreased. In the case that silica fume was used, the content of 10% silica fume was most effective in improving strength. In the case that carbon fibers were used, the content of 3% carbon fiber were good to achieve the highest flexural strength, and Pan-derived CF was much better than pitch-derived CF in improving these effects.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.15-18
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• 2003

Development of the construction industry generally exhausts natural aggregate. Hence it is problem to the lack of supply and quality deterioration, so the resource saving and protection of environment is made an effort through recycling by-product. This study presents that fundamental properties of concrete which used cooper slag as alternate sand of low fineness modulus and plan of cooper slag as concrete aggregate. Testing factors are concrete's slump, air contents, unit weight and compressive strength. The results of this study are as follows; (1) Concrete slump is generally satisfied with the condition but is inferior to the others in substitution rates 30%. Also air contents are 3.1-4.1% and go up according to increase substitution rate. (2) Unit weight increase in 1.1% as the mixing ratio of cooper slag argument 10%. (3) compressive strength of cooper slag concrete is similar to plain and especially higher 11-15% in W/C 45%, 50%. So it seems that aggregate mixed cooper slag is suitable to low water-cement ratio mixture.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.485-488
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• 2003

The results of an experiment on the sound absorption of the porous concrete using recycled aggregates and its influence on the compressive strength are reported in this paper. The content of recycled aggregate of 0, 10, 30, 50 and 70%, and the design void ratio of 30 percent for a given size of aggregate were used. In the compressive strength, an aggregate of the size of 5~13mm is much higher strength than that of the 13~20mm, In sound absorption experiment, the sound absorption ratio was is subjected to decreased as the content of recycled aggregates was increased. As a result, Porous concrete using recycled aggregates and by-products sufficiently have the performance of sound absorption.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.208-209
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• 2017

This study analyzed the fluidity and strength properties of mortar containing high volume blast furnace slag by replacement ratio of lightweight fine aggregate for reducing the unit weight of concrete structures.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.2
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• pp.137-146
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• 2001

The non-destructive tests are widely used to predict the strength of existing structures. The purpose of the present study is to propose the prediction equations for strength evaluation of concrete structures. The present study focuses on the rebound method and ultrasonic pulse velocity method for quartzite aggregate concrete. The major test variables include the water-cement ratio and curing methods. The water-cement ratio are 0.4, 0.5, 0.6, 0.7, respectively and the curing method covers ail-dry condition and standard curing condition. The prediction equations for strength of concrete are proposed from the present test data.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.301-307
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• 1996

High flowing concrete has been made using a combination of much amount cementitious materials and addition of SP agents, so that it makes possible to high flowing properties of fresh concrete. In the fluid mechanical and rheological point of view, high flowing concrete is affected on the relation between cement paste and aggregate of volume. In this experimental study, it is measured high flowing concrete of slump-flow about 65$\pm$5cm according to 0.54~0.80 of volume ratio and to analysed the properties of high flowing concrete in fresh and hardened concrete. It is the aim of this study to consider the affection of high flowing properties accoring to cement paste to aggregate ratio of volume on the combination of concrete.