• Proceedings of the Korean Institute of Building Construction Conference
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• v.y2004m10
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• pp.71-76
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• 2004

This paper investigate that the effect of the concrete containing mineral admixtures(pozzolanic materials such as fly-ash, ground granulated blast-furnace slag, silica fume and meta kaolin) on the resistance properties to chloride ion invasion. The purposed testing procedure was applied to the concrete added mineral admixtures for $3\sim4$ replacement ratios under W/B ratios ranged from 0.40 to 0.55. Specimens were immersed in $3.6\%$ NaCl solution for 330 days, and penetration depth, water soluble chloride contents and acid soluble chloride contents were measured in 28, 91, 182 and 330 days. Then, diffusion coefficient were calculated using total chloride contents. As a results. the kinds of mineral admixture and replacement ratios had a great effect on the resistance property of the concrete to chloride ion invasion compared with the plain concrete. And the optimal replacement ratios of mineral admixture had a limitation for each admixtures. The amount of acid soluble chloride ions and water soluble chloride ions were varied with the kinds of mineral admixtures and the penetration depth from the concrete skin. Chloride diffusion coefficient of each concretes decreased with the time elapsed. and the diffusion coefficients of the concrete immersed salt water for 330 days had a establishment with the compressive strength measured before immersing.

• Journal of the Korea Institute of Building Construction
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• v.10 no.5
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• pp.37-44
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• 2010

This study examined the practical application of ground granulated blast-furnace slag (GGBS) based alkali-activated (AA) binders for the development of cementless environmental-friendly secondary products of concrete, such as brick, shore protection blocks and interlocking blocks. The addition amount and type of alkaline ion to activate GGBS varied according to the diverse qualities of the secondary products of concrete required in Korean industrial standards (KS) and other specifications. Test results showed that the secondary products of concrete using GGBS-based AA binders surpassed the demanded capacities of KS and other specifications. In addition, shore protection block had a pH value close to neutral, enabling an advantageous environment for marine life. Therefore, the GGBS-based AA binders can be effectively applied to develop eco-friendly secondary products of concrete with reduced $CO_2$.

• Journal of the Korea Institute of Building Construction
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• v.9 no.6
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• pp.71-78
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• 2009

The analysis of the effect of loading on chloride penetration into concrete is very important. In this study, we confirmed that the chloride penetration rates for plain and BFS concrete were increased by 47% and 89% under compressive stress, respectively. The diffusion coefficient of BFS concrete was lower than for conventional concrete with no BFS, no loads, and under stressed states. Therefore, BFS substitution plays an important role in the repression of chloride penetration even under compressive stress. Under compressive stress,the diffusion coefficient for BFS concrete was higher with increasing stress, and this was also the case for plain concrete. However, BFS concrete was strongly influenced by compressive stress in comparison to plain concrete. We investigated the effect of the difference of specific surfaces on the diffusion coefficient. As a result, the larger specific surface of BFS exhibited a lower diffusion coefficient. This tendency was most pronounced under the high stress conditions.

• Resources Recycling
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• v.27 no.3
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• pp.39-47
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• 2018

According to Vietnam government establishes additional coal-fired power plants to secure generation capacity, emission of ashes is accelerating and processing them is urgent issue. This study targeted utilize fly ashes that occurred in circulating fluidized bed combusion (CFBC) power plant to use ground solidification materials. CFBC fly ashes are used to make solidification with ground granulated blast furnace slag (GGBFS), gypsum and cement. Then produced specimens by mixing with soft ground soil to confirm mixing effect of fly ash in solidification. As a result it was possible to find mixture design that is satisfied 3 MPa compressive strength in age 28 days and reduce weight loss rate over 50% in acid immersion test than plain specimens that using only ordinary portland cement.

• International Journal of Highway Engineering
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• v.15 no.4
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• pp.65-73
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• 2013

PURPOSES : As a research to develop a cement treated base course for an airport pavement which can enhance its drainage, this paper investigated the strength, infiltration performance and durability of the pervious concrete with respect to maximum coarse aggregate sizes and compaction methods. METHODS : This study measured compressive strength, infiltration rate, continuous porosity and freeze-thaw resistance of pervious concrete specimens, which were fabricated with five different compaction methods and different maximum aggregate sizes. In addition, in order to reduce the usage of Portland cement content and to enhance environment-friendliness, a portion of the cement was replaced with Ground Granulated Blast Furnace Slag (GGBS). RESULTS: Compressive strength requirement, 5 MPa at 7 days, was met for all applied compaction methods and aggregate sizes, except for the case of self-compaction. Infiltration rate became increased as the size of aggregate increased. The measured continuous porosities varied with the different compaction methods but the variation was not significant. When GGBS was incorporated, the strength requirement was successfully satisfied and the resistance to freezing-thawing was also superior to the required limit. CONCLUSIONS: The infiltration rate increased as the maximum size of aggregate increased but considering construct ability and supply of course aggregate, its size is recommended to be 25mm. With the suggested mix proportions, the developed pervious concrete is expected to successfully meet requirements for strength, drainage and durability for cement treated base or subbase course of an airport pavement.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.1
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• pp.9-17
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• 2016

In this study, binary blended concrete mix with fly ash and ground granulated blast furnace slag was prepared according to 3 level of water reduction performance of chemical admixture (0%, 8% and 16%) and 3 level of water-cement ratio (40%, 45% and 50%) for evaluation of quality properties of binary blended concrete according to performance of chemical admixture. concrete mix was carried out repetition test of three times in order to secure the reliability. As a result, compressive strength according to performance of chemical admixture was found that difference of strength was about 20% occurred, chemical admixture was showed that a great influence on qualities of concrete. In addition, reflected the effect of performance of chemiacal admixture, prediction model equations for concrete compressive strength was proposed, it was found that more than 85% of the high correlation.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.725-728
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• 2008

This study was to establish 3 levels of high fineness fly ash like 4000, 6000, and 8000 class and 30% replacement ratio in order to analyze mechanics and shrinkage properties of concrete by using high fineness fly ash. Furthermore, this study was to make a plan in two levels of water-binder ratio like 40% and 50%. In addition, as a result of measurement by the establishment of combined condition of ternary system as 20% replacement ratio level of three sorts of ground granulated blast furnace slag, there was a tendency to be equal or higher to the plain concrete as the fineness of fly ash increased in strength property. Simultaneously, this study had a tendency in the relationship between the compressive strength and elastic modulus that the more the fineness of fly ash, the more the elastic modulus increased a little. In addition, this study had a tendency that the more elastic modulus moved to the long-term aged one, the more it increased definitely. The effect on the fineness of fly ash remained at a low level in the drying shrinkage. This study has shown that the more the fineness increased, the more the elastic modulus decreased.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.885-888
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• 2008

In recent years, the terminology "High-Performance Concrete(HPC)" has been introduced into the construction industry. Most high-performance concretes have a high cementitious content and a low water-cementitious material ratio. The proportions of the individual constituents vary depending on local preferences and local materials. Therefore, many trial batches are usually necessary before a successful mix is developed. The objective of this experiments is to investigate the fundamental properties of high performance concrete based binary cimentitious materials such as ordinary portland cement and ground granulated blast furnace slag. The results from the study will be utilized as the basic data and guideline in making standard mixproportions and the manufacture, construction work and quality control of HPC

• Journal of the Korea Institute of Building Construction
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• v.15 no.4
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• pp.383-389
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• 2015

The objective of this study is to develop mixture proportioning approach of crack controlled lightweight foamed concrete without using high-pressure steam curing processes, as an alternative to autoclaved lightweight concrete blocks (class 0.6 specified in KS). To control thermal cracks owing to hydration heat of cementitious materials, 30% ground granulated blast-furnace slag (GGBS) was used as a partial replacement of ordinary portland cement (OPC). Furthermore, polyvinyl alcohol (PVA) and polyamid (PA) fibers were added to improve the crack resistance of foamed concrete. The use of 30% GGBS reduced the peak value of hydration production rate measured from isothermal tests by 28% and the peak temperature of foamed concrete measured from semi-adiabatic hydration tests by 9%. Considering the compressive strength development, internal void structure, and flexural strength of the lightweight foamed concrete, the optimum addition amount of PVA or PA fibers could be recommended to be $0.6kg/m^3$, although PA fiber slightly preferred to PVA fiber in enhancing the flexural strength of foamed concrete.

• Journal of the Korea Concrete Institute
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• v.13 no.2
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• pp.175-183
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• 2001

Immersion tests with artificial seawater were carried out to investigate the resistance to seawater attack of 5 types of cement matrices. From the results of compressive strength and length change, it was found that blended cement mortars due to mineral admixtures, were superior to portland cement mortars with respect to the resistance to seawater attack. Moreover, XRD analysis indicated that the peak intensity ratio of low heat portland cement(LHC) paste, in portland cement pastes, had better results, and so did that of blended cement Paste. Pore volume of pastes by mercury intrusion porosimetry method demonstrated that total pore volume of ordinary portland cement(OPC) paste had a remarkable increase comparing with that of other pastes. In case of immersion of artificial seawater, the use of ground granulated blast-furnace slag and fly ash, however, showed the beneficial effects of 56% and 32% in reduction of total pore volume, respectively.