• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.1035-1040
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• 2001

The effects of polymer-binder ratio and slag content on the properties of combined wet/dry-cured polymer-modified mortars using granulated blast-furnace slag (slag) are examined. As a result, the flexural and compressive strengths of polymer-modified mortar using slag reaches a maximum at a slag content of 40%, and is inclined to increase with increasing polymer-binder ratio. The water absorption, carbonation depth and chloride ion penetration depth tend to decrease with increasing polymer-binder ratio and slag content.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.315-320
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• 2002

The effects of slag content and polymer-binder ratio on the strength properties of the polymer-modified concretes using ground granulated blast-furnace slag and a styrene-butadiene rubber (SBR) latex are examined. As a result, the compressive, tensile and flexural strengths of the SBR-modified concretes using slag increase with increasing polymer-binder ratio and slag content, and maximized at a slag content of 40 ％. In particular, the SBR-modified concretes with a slag content of 40 ％ provide approximately two times higher tensile and flexural strengths than unmodified concretes. Such high strength development is attributed to the high tensile strength of SBR polymer and the improved bond between cement hydrates and aggregates because of the addition of SBR latex.

• Journal of the Korea Concrete Institute
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• v.14 no.2
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• pp.164-170
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• 2002

Effect of the polymer-binder ratio and slag content on the properties of combined wet/dry-cured polymer-modified mortars using granulated blast-furnace slag are examined. Results shows that the flexural and compressive strengths of polymer-modified mortar using the slag tend to increase with increasing slag content, and reaches a maximum at a slag content of 40 ％, and is inclined to increase with increasing polymer-binder ratio. Water absorption, carbonation depth and chloride ion penetration depth tend to decrease with increasing polymer-binder ratio and slag content. Accordingly, the incorporation of slag into polymer-modified mortars at a slag content of 40％ is recommended for a combined wet/dry curing regardless of the types of polymer.

• Computers and Concrete
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• v.16 no.2
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• pp.261-274
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• 2015

This study established the standard recommended values and expansion fracture threshold values for the content of steel slag in controlled low-strength materials (CLSM) to ensure the appropriate use of steel slag aggregates and the prevention of abnormal expansion. The steel slags used in this study included basic oxygen furnace (BOF) slag and desulfurization slag (DS), which replaced 5-50% of natural river sand by weight in cement mixtures. The steel slag mortars were tested by high-temperature ($100^{\circ}C$) curing for 96 h and autoclave expansion. The results showed that the effects of the steel slag content varied based on the free lime (f-CaO) content. No more than 30% of the natural river sand should be replaced with steel slag to avoid fracture failure. The expansion fracture threshold value was 0.10%, above which there was a risk of potential failure. Based on the scanning electron microscopy (SEM) analysis, the high-temperature catalysis resulted in the immediate extrusion of peripheral hydration products from the calcium hydroxide crystals, leading to a local stress concentration and, eventually, deformation and cracking.

• Journal of the Korean Ceramic Society
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• v.44 no.9
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• pp.477-482
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• 2007

The effect of the mixing ratio of compounds in a slag-OPC-Gypsum system on the physical properties of Slag cement is investigated in this study. $Na_2SO_4$ was used as an alkali activator. Blast furnace slag cement was prepared from a mixture of blast furnace slag, ordinary Portland cement and anhydride gypsum. The fluidity and the compressive strength according to the ratio of each mixture were analyzed in statistical analyses in order to discover the parameters influencing the fluidity and compressive strength. The results showed that the hydration of blast furnace slag took place with the addition of $Na_2SO_4$ and that column-crystalline ettringite was created as the main hydration product of the blast furnace slag. In addition, it was found that the compressive strength of blast furnace slag cement tends to increase when the ordinary Portland cement content is higher up to three days. However, it is known that the compressive strength tends to increase as the blast furnace slag content becomes higher with increases in the level of OPC after 28 days. As a result of this analysis, it is believed that the ordinary Portland cement content influences the initial compressive strength of blast furnace slag cement, and that in later days this is highly influenced by the slag content.

• Advances in concrete construction
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• v.12 no.6
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• pp.507-515
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• 2021

To evaluate the influence of slag on the alkalinity of pore solution and microstructure of concrete, this paper performs a leaching experiment on hardened cement-slag pastes (HCSP) slice specimens with different slag content in purified water. The pH value of pore solution, average porosity, morphology, phase composition and Ca/Si of HCSP specimens in the leaching process are measured by solid-liquid extraction, saturated-dried weighing, scanning electron microscopy-energy dispersive spectrometry (SEM-EDS) and X-ray diffraction (XRD). Results shows that the addition of slag can mitigate an increase in porosity and a decrease in Ca/Si of HCSP in the leaching process. Besides, an appropriate slag content can improve the microstructure so as to obtain the optimum leaching resistance of HCSP, which can guarantee the suitable alkalinity of pore solution to prevent a premature corrosion of reinforced bar. The optimum slag content is 40% in HCSP with a water-binder ratio of 0.45, and an excessive slag causes a significant decrease in the alkalinity of pore solution, resulting in a loss of protection on reinforced bar in HCSP.

• Journal of the Korea Institute of Building Construction
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• v.6 no.3 s.21
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• pp.107-114
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• 2006

In this study, the experiment was carried out to investigate and analyze the engineering properties of concrete using fine aggregate of PS bal slagl. The main experimental variables were water/cement ratio 30, 40, 50(%), water content $170kg/m^3$, replacement ratio of slag fine aggregate 0, 25, 50, 75(%) in experiment I and water/cement ratio 30, 40, 50(%), water content 165, 170, 175($kg/m^3$), replacement ratio of fine aggregate of PS ball 0, 50 in experiment II. According to the test results, the principle conclusions are summarized as follows (1) The workability of slag fine aggregate-mixed concrete tends to improve, as the replacement rate increases. (2) The air content of slag fine aggregate-mixed concrete tends to decrease, as the replacement rate increases. (3) The unit volume weight of slag fine aggregate-mixed concrete tends to significantly increase, as the replacement rate increases. (4) The compressive strength of slag fine aggregate-mixed concrete tends to show more increasing propensity, in case the curing period is relatively long, as the replacement rate increases.

• Journal of Urban Science
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• v.7 no.1
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• pp.39-43
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• 2018

This study investigates microstructural characteristics of alkali-activated cements incorporating slag and fly ash. Samples were prepared with four fly ash:slag ratios, i.e., 100:0, 90:10, 70:30 and 50:50, and they were synthesized by using an alkali activator. Microstructural characteristics of the alkali-activated cements were determined by XRD, TGA, SEM, N2 gas adsorption/desorption methods, and compressive strength test. The results showed that properties of alkali-activated fly ash/slag were significantly affected by slag contents. Alkali-activated fly ash/slag with slag content of 30-50% showed higher compressive strength than ordinary Portland cement paste. An increase in slag content resulted in a denser microstructure, which composed of amorphous gel, therefore contributed to strength development of the material.

• Journal of the Korea Concrete Institute
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• v.14 no.4
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• pp.608-614
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• 2002

The effects of slag content and polymer-binder ratio on the strength properties of autoclaved SBR-modified concretes using ground granulated blast-furnace slag(slag) and a styrene-butadiene rubber (SBR) latex are examined. As a result, the compressive and tensile strengths of the autoclaved SBR-modified concretes using slag increase with increasing slag content, and reach a maximum at a slag content 40％, and increase with increasing polymer-binder ratio. In particular, the autoclaved SBR-modified concretes with a slag content of 40％ provide about three times higher tensile strength than unmodified concretes. Such high strength development is attributed to the high tensile strength of SBR polymer and the improved bond between cement hydrates and aggregates because of the addition of SBR latex.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.120-123
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• 2003

In order to evaluate the applicability of steel slag aggregates for tetrapod concrete, the properties of concrete as structural material were investigated. The biochemical research of marine concrete using steel slag aggregates was also carried out. The tested concrete properties are slump, air content, compressive strength, splitting tensile strength, elastic modulus, carbonation, hydration heat, freezing and thawing, sulfate attack, drying shrinkage, etc. The biochemical experiments are carried to research the propagation and reproduction of seaweeds and survival of bottom dwelling species. According to the experimental results, the steel slag aggregate content did not have a significant effect on compressive strength, splitting tensile strength and elastic modulus. The durability of concrete was not influenced by the steel slag aggregate content. From the biochemical research, steel slag aggregate can be evaluated as the material that is ideally suited for promoting propagation and reproduction of seaweeds and survival of bottom dwelling species.