• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.299-304
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• 2002

This research was to investigate the invasion and diffusion properties of chloride ion on the concrete containing mineral admixtures by the electrically accelerated test. Mineral admixtures selected in mixes were fly-ash, ground granulated blast-furnace slag, silica fume, and meta-kaolin with 3 degrees of replacement ratios. Tang and Nilsson's test method was used to estimate chloride diffusion coefficients of that mixes. As a result, the total current passing charge and the diffusion coefficient of chloride ion were reduced with the use of mineral admixtures and the increase of replacement ratios. In addition, compressive strength was related with diffusion coefficient of chloride ion. Diffusion coefficients of concrete mixed with ground granulated blast-furnace slag showed relatively low value under the range of compressive strength of 400㎏f/㎠.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.269-274
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• 1998

In this study, to increase fluidity and resistance of segregation of materials, the effect of each of the materials, which have effects on high performance concrete from investigating the properties of strength and drying shrinkage of high performance concrete made by the basic mix proportion used fly-ash and ground granulated blast-furnace slag after hardening, has been checked. According to the experimental results, fluidity on W/C = 34% was satisfied within slump-flow 65$\pm$ 5cm and U-type self-compactability difference 5cm. On the properties of strength, high performance concrete produced compressive strength over 400kg/$\textrm{cm}^2$ in 28days when powder was replaced by 40% of fly-ash and 60% of ground granulated blast-furnace slag. And compressive strength was taken over 600kg/$\textrm{cm}^2$ equal to non-replacement in 91days. Also, the length change of concrete with the addition of fly-ash was smaller than that without it. Therefore, it may be effective on the decrease of drying shrinkage volume.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.1193-1198
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• 2001

The glass of Ground Granulated Blast Furnace Slag(GGBFS) was released by the hydroxyl ions during the hydration of the Portland cement. That results in relatively less $Ca(OH)_{2}$ in the concrete replaced with GGBFS than in ordinary portland cement concrete(OPCC). As the quantity of $Ca(OH)_{2}$ is decreased, the rate of carbonation in the concrete replaced GGBFS is faster than OPCC. Therefore, it has been misunderstood that the concrete replaced GGBFS has negative effect on the corrosion of steel by carbonation. Therefore, this study aimed at the relation between carbonation and rebar corrsion in the concrete with GGBFS, measuring air.water permeability, half cell, and corrosion rate by the depth of carbonation.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.329-332
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• 2006

This paper presents the experimental results for durability of an ECC designed with ground granulated blast furnace slag (BFS) through the test method of chloride ion resistance and freezing-thawing resistance. In order to compare with ECC, normal mortar was also tested. Test results showed that BFS ECC exhibited higher durability performance than ordinary mortar. These results suggest that by adding BFS in ECC, its matrix density is increased which results in decreased of deterioration and it also adds to the fiber bridging that contributes in control of cracking.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.555-556
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• 2009

The purpose of this study is to estimate compressive strength of concrete using granulated blast furnace slag. We used Sodium silicate, Potassium silicate, Barium hydroxide as alkali activators and Calcium hydroxide to develop water resistance.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.945-950
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• 2000

Coastal concrete structure is harmed by physical and chemical action of sea water, impact load, meteorological effect and etc. especially, premature reinforcement corrosion in concrete exposed to sea water has an important problem. In this study, the behavior of chloride ions penetrated through the coastal concrete structure with ordinary portland cement or ground granulated blast furnace slag(GGBFS) was modeled. The physicochemical processes including the diffusion of chloride and the chemical reaction of chloride ion with calcium silicate hydrate and the other constituents of hardened cement paste such as$C_3A$ and $C_4AF$were analyzed by using the Finite Element Method. From analysis result, the corrosion of concrete structure with GGBFS begins 1.69~1.76 times later than that of concrete structure with ordinary portland cement.

• Journal of the Korea Institute of Building Construction
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• v.3 no.3
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• pp.73-81
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• 2003

In this paper, salt damage resistance of high durable concrete was tested. High durable concrete was made by using low water cement ratio, chemical admixture called super-durable admixture and mineral admixtures such as fly-ash, ground granulated blast-furnace slag, silica fume. Two kinds of salt damage resistance test were carried out. One method is chloride ion penetration test(ASTM C1202), and the other one is depth of chloride penetration test in saline solution. Test results were as followers: 1) The depth of chloride ion penetration increased exponentially as water cement ratio was increased and time passed. 2) Super-durable admixture had little effect on the improvement of salt damage resistance of concrete. 3) Silica fume and ground granulated blast-furnace slag were effective on salt damage resistance because of pozzolanic reaction, but fly-ash had a little effect.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.881-884
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• 2006

Wasted phosphogypsum is a by-product from the phosphoric acid process of manufacturing fertilizers. It consists mainly of $CaSO_4{\cdot}2H_2O$ and contains some impurities. The purpose of this study is to utilize wasted phosphogypsum into an admixture for concrete products cured by steam This paper is to investigate the strength properties of cement composites containing high volume phosphogypsum. The cement composites were composed of OPC, phosphogypsum, fly-ash and granulated blast-furnace slag with activators. As a result, the strength of cement composites containing high volume wasted phosphogypsum were shown high level when granulated blast-furnace slag was mixed. Therefore, PG could be used as a steam curing admixture for concrete 2th production with reduction of OPC.

• Advances in concrete construction
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• v.4 no.4
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• pp.283-303
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• 2016

Several types of industrial byproducts are generated. With increased environmental awareness and its potential hazardous effects, the utilization of industrial byproducts in concrete has become an attractive alternative to their disposal. One such by-product is ground granulated blast furnace slag (GGBS), which is a byproduct of the smelting process carried out in the iron and steel industry. The GGBS is very effective in the design and development of high-strength and high-performance concrete. This paper reviews the effect of GGBS on the workability, porosity, compressive strength, splitting tensile strength, and flexural strength of concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.17-18
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• 2022

Carbon dioxide emissions in the construction sector account for 38% of all industries, and environmental destruction is occurring due to indiscriminate use of natural resources. The purpose of this study is to develop by-product aggregate Non-Sintered Cement(NSC) that can replace sand used as natural aggregate and Portland cement. Therefore, Ground Granulated Blast Furnace Slag, Type C Fly Ash and Type F Fly Ash are used to replace cement, and water granulated ferro-nickel slag(FNS) is used to replace aggregate. The flow, compressive strength and flexural strength of the formulation using sand as an aggregate and the formulation replacing 100% FNS were compared. As a result of the experiment, the formulation using FNS had higher overall strength than the formulation using sand, and as the substitution rate of Type C fly ash increased, the strength was the best. Formulation using FNS is more fluid than using sand. Through this study, we show the possibility of 100% substitution of FNS and its applicability to secondary concrete products of by-product aggregate NSC.