• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.11a
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• pp.101-104
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• 2005

The world's cement demand is anticipated to increase about 2.558$\%$ every year until the first half of the 21st century. To be closed the increase of cenment damand and simultaneously comply with the Kyoto Protocal, cement that gives less carbon dioxide(Co2) discharge should be urgently developed. If cement can be manufactured with industrial byproducts such as granulated blast furnace slag(GBFS), phosphogypsum(PG), and waste lime(WL) instead of clinker as its counterproposal, there would be many advantages including maximum use of these industrial byproducts for high value-added resources, conservation of natural resources and energy by omitting the use of clinker, minimized environmental pollution problems caused by Co2 discharge and reduction of the cost. So this study aims to solve the problems by manufacturing non-sintered cement.

• Journal of the Korean Ceramic Society
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• v.42 no.11 s.282
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• pp.737-742
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• 2005

Rheological properties of ordinary portland cement (OPC) containing metakaoline (MK), granulated blast furnace slag (GBS) and polycarboxylate type superplasticizer (PCA) were investigated using a mini-slump test, sedimentation test and viscometer. Fluidity of cement pastes containing MK (OPC-MK, OPC-MK-GBS systems) with PCA were higher than those of the cement pastes without MK(OPC, OPC-GBS systems). Colloid suspensions with $0.1\%$ PCA were changed from stable sedimentation behaviors to flocculation behaviors in the OPC-MK, OPC-GBS and OPC-MK-GBS systems. The colloid suspensions showed stable sedimentation behaviors with PCA greater than $0.2\%$. The OPC system showed shear thinning behavior. However, the other systems showed weak shear thinning behaviors with PCA. Rheological properties of cement pastes were improved when MK and GBS were contained together. The rheological properties of OPC-MK, OPC-GBS and OPC-MK-GBS systems were improved by PCA added greater than $0.2\%$.

• Journal of the Korea Concrete Institute
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• v.11 no.4
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• pp.31-41
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• 1999

Blended Low Heat type cement is ground granulated blast furnace slag and fly ash mixed ternary with ordinary portland cement. From the viewpoint of X-ray patterns of domestic LHC, the main components of cement such as $C_2$S, $C_3$A, $C_3$S are considerably reduced. Therefore the heat evolution of LHC paste is 42cal/g lower than of OPC paste. At early age, the compressive strength development of LHC concrete is delayed, but the slump loss ratio of fresh concrete is reduced more than 20% with elapsed time. The penetrability of LHC is lower than that of OPC by 1/7.8 with the penetrability of chloride ion into the concrete until the age of 120 days. And the PD Index value of LHC is 0.44$\times$10-6 $\textrm{cm}^2$/s, which indicates only 39.3% of OPC. From the Mercury Intrusion Porosimetry test of cement past, we know that the pore size of LHC is more dense than that of OPC by production of C-S-H.

• Advances in concrete construction
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• v.3 no.3
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• pp.223-236
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• 2015

Concrete is the most widely used material of construction. Concrete gained the popularity as a construction material due to the easy availability of its component materials, the easy formability, strength and rigidity upon setting and curing.In construction industry, strength is the primary criterion in selecting a concrete for a particular application. Now a days, the substantial amount of waste materials, containing the properties of the Pozzolana, is being generated from the major industries; and disposal of such industrial wastes generated in abundance is also a serious problem from the environmental and pollution point of view. On this backdrop, efforts are made by the researchers for exploring the possible utilization of such waste materials in making the sustainable construction material. The present paper reports the experimental investigations to study the strength characterization of concrete made from the pozzolanic waste materials. For this purpose, the Pozzolanic materials such as fly ash and ground granulated blast furnace slag were used as a cement replacing materials in conjunction with ordinary Portland cement. Equal amount of these materials were used in eight trial mixes with varying amount of cement. The water cement ratio was also varied. The chemical admixture was also added to improve the workability of concrete. The compressive strengths for 7, 28, 40 and 90 days' were evaluated whereas the flexural and tensile strengths corresponding to 7, 28 and 40 days were evaluated. The study corroborates that the pozzolanic materials used in the present investigation along with the cement can render the sustainable concrete.

• Journal of the Korea Concrete Institute
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• v.22 no.3
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• pp.375-380
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• 2010

In this study, physical properties of cement blended with Finex-slag powder(OPC-FS) were investigated by the measurement of flowability, compressive strength, hydration heat, and $Ca(OH)_2$ content. In addition, those properties of the cement blended with blast furnace slag(OPC-BFS) were also measured for comparison. It was found that OPC-FS and OPC-BFS showed similar trend in the rheological properties. In the blended cement pastes with the $4,000\;cm^2/g$ Blaine value the flowability of OPCFS was better than that of OPC-BFS. The initial 3 day mortar compressive strength and the hydration heat of paste of OPC-FS was a bit higher, compared with OPC-BFS. Accordingly $Ca(OH)_2$ produced in the cement hydration was decreased very rapidly.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.105-106
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• 2021

This study examines the performance of CBS-Dust for the utilization of cement bricks as alkali stimulants for furnace slag replacement binders. It converts the CBS-Dust substitution rate and the excess slag substitution rate. According to the analysis, when replacing CBS-Dust with 65~70 % of BS substitution rate and 7.5~10 % of CBS-Dust, it shows excellent performance as an alkali stimulant of BS' potential hydrophobic reaction, and it is expected to be effective for secondary products of BS replaced in large quantities.

• Korean Journal of Materials Research
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• v.13 no.2
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• pp.94-100
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• 2003

The interface between low carbon steel and blended cement pastes containing slag was investigated using impedance spectroscopy. In addition, the pastes were characterized by several analytical methods (XRD, EDX, electrode potential, pH and ICP). The electrical behavior of the interface in the blended slag systems is correlated to its corresponding pore solution chemistry and the products present in the interface. Passivation occurred at the paste/steel interfaces, in cement pastes up to containing from 0 to 75% slag content. 100% slag paste induced corrosion of the low carbon steel, which could be explained by the influence of sulfur on the system.

• Journal of the Korea Institute of Building Construction
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• v.4 no.4
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• pp.79-86
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• 2004

The purpose of this study was the development of a recycling process to recover the hydraulic properties of hydration products which account for a large proportion of cementitious powder from concrete waste. This process was performed to recycle cementitious powder as recycle cement. Therefore, after the theoretical consideration of the properties of recycle process of recycled aggregates and cementitious powder, we investigated the hydraulic properties of cementitious powder under various temperature conditions in hardened mortar which was modeled on concrete waste. And we analyzed properties of chemical reactions of recycled cement with admixture materials such as Fly-Ash, Blast Furnace Slag As a result of the experiment, the most effective method to recover hydraulic properties of the cementitious powder from concrete waste was condition of burning at 700℃ for 120 minute. And it is shown that the fluidity of mortar was decreased rapidly when the burning temperature of recycle cement was increased. However, the compressive strength and fluidity were improved significantly when admixture materials such as Fly-Ash or Blast Furnace Slag was added.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.5
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• pp.37-44
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• 2014

The physical, mechanical and freezing and thawing properties of non cement porous vegetation concrete using non-sintering inorganic binder have been evaluated in this study. Four types of porous vegetation concrete according to the binder type is evaluated. The pH value, void ratio, compressive strength, repeated freezing and thawing properties were tested. The test results indicate that the physical, mechanical and repeated freezing and thawing properties of porous vegetation concrete using the non-sintering inorganic binder is increased or equivalent compared to the porous vegetation concrete using the blast furnace slag + cement and hwang-toh + cement binders. Also, Vegetation monitoring test results indicate the porous vegetation concrete using the non-sintering inorganic binder have increasing effects of vegetation growth.

• Journal of the Korea Institute of Building Construction
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• v.21 no.2
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• pp.97-104
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• 2021

This study aims to develop non-sintered cement that can replace the Portland cement by utilizing industrial by-products. As a suggestion, the physical properties of non-sintered cement mortar depending on the curing method were investigated with ground granulated blast furnace slag, class C fly ash, and class F fly ash. As a result of the study, it was found that the strength performance and absorption rate were improved through the heat treatment process after steam curing. It was confirmed through crystal phase analysis that the hydration was accelerated after heat treatment, and the bonding material formed a dense internal structure.