• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.1
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• pp.17-24
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• 2024

The characteristics of low-heat concrete, mixed with ground blast furnace slag and ferronickel slag aggregate, were analyzed. Moreover, the applicability of this concrete for mass concrete in LNG storage tanks was examined. Initially, the study investigated the characteristics of fresh and hardened concrete. Subsequently, the temperature rising curve was obtained. Utilizing the obtained parameters from the curves, a series of thermal stress analyses for the LNG storage tank were conducted to assess the risk of cracking. The results confirmed that concrete mixtures incorporating ground blast furnace slag and ferronickel slag aggregate not only exhibited sufficient workability but also achieved a compressive strength of approximately 40 MPa within 28 days. Furthermore, the concrete demonstrated a lower terminal heat rise and a faster heat generation rate compared to low-heat Portland cement concrete. An analysis of thermal stress in various sections of the LNG tank validated a low risk of cracking.

• Journal of the Korea Institute of Building Construction
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• v.22 no.6
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• pp.641-649
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• 2022

This study aims to completely develop a non sintered cement mortar using industrial by-products. To replace Portland cement, blast furnace slag, circulating fluidized bed fly ash, and pulverized coal fly ash were used, and natural aggregates were substituted with ferronickel slag. To understand the characteristics of the non sintered cement mortar to which ferronickel slag is applied, an experiment was conducted by classifying the particle size. Fluidity and workability were confirmed through the flow test, and bending and compressive strength tests were conducted at 3, 7, and 28 days of age. In addition, durability was identified through a chloride ion penetration test. Through the study, it is judged that the binder, which completely replaced cement and aggregate, has high potential of being used as a construction material. Notably, it was confirmed to be advantageous for strength and durability.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.3
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• pp.214-221
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• 2018

In this paper, the effects of ferronickel slag powder and admixture on the strength of VR sewer pipe were analyzed. the substitution rate was tested as a variable, and the strength development was studied through the flexural strength, compressive strength and using SEM microscopic analysis. bending strength, compressive strength results and micro analysis using SEM showed the correlation in each case. the substitution rates were 20% and 30% relative to the mass of the OPC respectively, and were substituted according to a constant ratio of ferronickel slag fine powder and mixture. when the substitution ratio was 20%, the strength development was excellent. also, bending strength and compressive strength were the best when the ferronickel slag fine powder, quicklime, gypsum and calcium chloride were used as the admixture, dense microstructural patterns appeared. the possibility of progressive strength development is shown after 28 days.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.545-552
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• 2021

In this study, strength and durability evaluations are performed on vibrated-rolled method mortar mixtures containing desulfurized gypsum and ferronickel slag powder. Desulfurized gypsum and ferronickel slag fine powders were substituted for 25% limestone fine powders u sed in the manu factu re of VR tu bes, and mortar specimens were prepared u sing vibrated-rolled method. Accordingly, flexural and compressive strengths were performed to evaluate the strength, and chlorine ion penetration resistance and sulfuric acid resistance tests were performed to evaluate durability. Flexural and compressive strength were improved in the range 20 to 60% of desu lfu rized gypsu m among admixtu res, and the amou nt of passing charge decreased in the choride ion penetration resistance test in the range of 20 to 80% of desulfurized gypsum. As for the resistance to su lfu ric acid, when the proportion of desu lfu rized in the admixtu re was 40%, the strength and weight change rate according to the immersion period was reduced. Appropriate use of desulfurized gypsum and ferronickel slag powder is expected to improve performance in terms of strength and durability.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.2
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• pp.152-160
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• 2021

Converter steel slag(BOF slag) is a vast amount of solid waste generated in the steelmaking process which has very low utilization rate in Korea. Due to the presence of free CaO which can derive bad volume stability in BOF slag, it usually land filled. For recycling BOF and identify its applicability as fine aggregate, this study investigates the fundamental characteristics of mortar with cement replaced ferronickel slag(FNS), which has the potential to be used as a binder. The results suggest that the mineral phases of BOF slag mainly include larnite(CaSiO₄), mayenite(Ca₁₂Al₁₄O₃₃) and wuestite(FeO) while olivine crystallines are shown in FNS. The results of flow and setting time reveals that the flowability and process of hardening increased when the amount of FNS and BOF slag incorporated was increased. The length change shows that the amount of change in the length of the mortar was almost constant regardless of mix proportion while compressive strength was reduced. Micro structure test results revealed that FNS or/and BOF slag mix took a long time to react in the cement matrix to form a complete hydration products. To achieve the efficient utilization of B OF slag as construction materials, proper replacement rate is necessary.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.16-21
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• 2017

The aim of this study was to utilize ferronickel slag produced in the manufacture of stainless steel as a flowable backfill material for underground use using crushed fine powder. Experimental combinations were made using two components: Case A (sand) and Case B (soil). The optimal mixing ratio of Case A was sand (58.4%), ferronickel slag fine powder (21.6%), cement (1.8%), and water (18.2%). In the case of B, the optimal mixing ratio was determined to be soil (53.0%), ferronickel slag fine powder (20.0%), cement (1.7%), and water (25.3%). The uniaxial compressive strength of case A, which is a mixture of ordinary sand and ferronickel slag powder, was relatively larger than that of case B using soil. In addition, the strength of the specimen increased with increasing curing time. The uniaxial compressive strength tended to increase with increasing curing time. In addition, the unconfined compression strength of the fluid backfill material using common sand as the main material was relatively larger than that of the mixed material using soil as the main material. In case A, the uniaxial compressive strength ranged from 0.17-0.33 MPa, 0.21-0.39 MPa, and 0.19-0.40 MPa, respectively, at curing times of 7, 14, and 28 days. From the experimental results, it was concluded that the ratio of FNS powder and cement mixture was the most appropriate for Case A3. Case B, which used soil as the main material, showed a similar tendency to Case A. As a result of the dissolution test for evaluating the environmental harm of the FNS fine powder, there was no dissolution of substances harmful to the environment.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.2
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• pp.190-197
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• 2020

This paper evaluates the mechanical properties and durability of cement matrix blended with mineral admixtures and ferronickel slag(FNS) powder which is an industrial b y-product during ferronickel smelting process. The hydration heat, pore structure, compressive strength, length change, rapid chloride penetration test(RCPT), and freezing and thawing resistance of ternary blended cement matrix were investigated and compared with ordinary portland cement matrix. The result showed that the compressive strength of ternary blended cement matrix using ferronickel slag powder and mineral mixture was low in strength compared to the reference concrete, but recovered to a certain extent by using alkali activator. Length change of cement mortar using FNS powder have shown less shrinkage occurs than the reference specimen. In addition, irrespective of using the alkali-activators, all ternary mix are indicative of the 'very low' range for chloride ion penetrability according to the ASTM C 1202, and the freeze-thaw resistance also showed excellent results.

• Journal of the Society of Disaster Information
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• v.14 no.4
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• pp.430-439
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• 2018

Purpose: The purpose of this study is to verify the effectiveness of maintenance method using GPR exploration by buried detective materials in the ground for efficient maintenance of recovered cavities. Method: EMI sheet, EMI paint, and ferronickel slag were used as the detection materials, and the experiment was conducted by varying the size and depth of the buried detectable material. Results: As a result of the exploration, Detectable influence range by GPR exploration was found depending on the size and depth of buried detectable material in all materials, and the possibility of using it as a detection material was confirmed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.259-260
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• 2022

In this study, as part of a study to solve the problem of aggregate supply and demand, blast furnace slag fine aggregate and ferronickel slag fine aggregate were used as substitutes for natural fine aggregate, and a bioinspired polymer, a catechol-functionalized chitosan, was used instead of the mixing water.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.78-79
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• 2021

In this study, the fluidity and compressive strength properties of concrete according to the mixing ratio of mixed slag aggregates were compared as part of research to alleviate the aggregate supply problem and improve environmental pollution by utilizing industrial by-products.