• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.143-150
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• 1994

To improve the qualities of high strength mortar and concrete with high range water reducing admixture, silica fume and gypsum is applied. The flow loss of mortar is reduced and the compressive strength of mortar and concrete is improved by silica fume. And the silica fume is effective for decreasing the temperature of high strength concrete. In addition to, the strength of high strength concrete is more improved by the gypsum.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.31-32
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• 2020

This study measured the mechanical performance and residual strength of high strength/normal strength mortar mixed with waste glass fine aggregate after alkali-silica reaction and alkali-silica reaction. As a result, the effect of improving the slip phenomenon of the waste glass fine aggregate in the high-strength mortar was not significant, but rather the amount of ASR was increased.

• Computers and Concrete
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• v.24 no.4
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• pp.329-345
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• 2019

Despite the extensive use of mortar materials in constructions over the last decades, there is not yet a robust quantitative method, available in the literature, which can reliably predict mortar strength based on its mix components. This limitation is due to the highly nonlinear relation between the mortar's compressive strength and the mixed components. In this paper, the application of artificial neural networks for predicting the compressive strength of mortars has been investigated. Specifically, surrogate models (such as artificial neural network models) have been used for the prediction of the compressive strength of mortars (based on experimental data available in the literature). Furthermore, compressive strength maps are presented for the first time, aiming to facilitate mortar mix design. The comparison of the derived results with the experimental findings demonstrates the ability of artificial neural networks to approximate the compressive strength of mortars in a reliable and robust manner.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.486-490
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• 1999

In this study, to improve the required properties of tile cement mortar such as excellent water retention capacity (WRC), workability, open time, sag resistance, and tile adhesive strength, tile cement mortars containing the several additives with different ratio were compared and analyzed. By adding small amount of synthesized starch to hydroxypropyl methylcellulose (HPMC) which is used for improving WRC, the decrease of moisture evacuation from mortar surface was observed and the workability of mortar was improved with long open time. Polyacrylamide (PAAm) and ethylencvinyl acetate (EVAc) were also added in order to increase the adhesion of tile. As a results, the saggings of mortar itself and tile were decreased and the adhesive strength of mortar between base and tile was enhanced. By adding melment, the workability was improved by increasing the fluidity of mortar. It is postulated that the properties of tile cement mortar was improved by adding 0.80~1.20% of HPMC, 0.10~0.15% of starch, 0.001~0.015% of PAAm, 0.05~0.10% of EVAc and 0.003~0.005% of melment to the cement mortar.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.7
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• pp.179-186
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• 2019

Air lime is a traditional building material of Korea. It had been used in roofs, walls, floors and masonry joints of traditional buildings until the advent of Portland cement. However, due to its low strength and durability, the lime is currently avoided as a repair or restoration material for the preservation of architectural heritage. Furthermore, due to the current practice of using hydraulic materials such as Portland cement, understanding of the material characteristics of air lime is very poor in practice. In this context, this study intended to improve the mechanical properties of the air lime mortar by reducing water contents, and also the carbonation reaction of the mortar was quantitatively evaluated to clearly understand the characteristics of this material. Accordingly, air lime mortar with a water-to-binder ratio of 0.4 was manufactured using polycarboxylate-type superplasticizer. During the 7 days of sealed curing period, the mortar did not harden at all. In other words, there was no reaction required for hardening since it could not absorb carbon dioxide from the atmosphere. However, once exposed to the air, the compressive strength of the mortar began to rapidly increase due to the carbonation reaction, and the strength increased steadily until the 28th day; after then, the strength development was significantly slowed down. On the 28th day, the mortar exhibit a compressive strength of about 5 MPa, which is equivalent to the European standard regarding strength of hydraulic lime used for preservation of architectural heritage.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.684-687
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• 2004

The purpose of this study is to obtain basic data on the properties of the development of lightweight mortar contained foam agent for various applications in the field. In the experiment, as a result of measurement the specific gravity by the change of the W/C and the foam agent into a variable and measuring the compressive strength of mortar, specific gravity checked that a compressive strength therefore increased. Mortar is using lightweight foam agent having the change of specific gravity, the water cement ratio $50\%,\;40\%,\;30\%$. This paper present extensive data on the characteristics of strength of the lightweight mortar and also presents the mechanical characteristics of the lightweight according to specific gravity.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.215-216
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• 2011

This study investigates the effect of partial replacement with cement on the properties of blast furnace slag-based mortar. Recycled fine aggregate with various contents was used to activate the hydration of blast furnace slag in the mortar and compared its effect on strength development. Results showed that increasing cement and recycled fine aggregate increased the strength of mortar specimens. However, this study found that the mortar made with partial replacement of river sand with recycled fine aggregate of 20% developed a similar strength to the strength that cement with 10% can achieved.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.193-196
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• 2003

In this paper, the experimental investigation for the setting properties of cement paste, the consistency and strength properties of mortar with steel furnace slag dust was performed and compared with those of cement paste and mortar with ground granulated blast furnace slag. When steel furnace slag dust was replaced with normal portland cement, setting time and flow value indicated to good results like as mortar with ground granulated blast furnace slag. However, mortar with steel furnace slag dust expressed to appreciably strength devaluation according to containing ratio, and did not indicate the pozzolanic reaction like as ground granulated blast furnace slag.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.2
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• pp.191-197
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• 2001

In this study, the admixtures for agents for enduring cold weather used widely are collected and applied to cement mortar to analyze the strength development due to variation of curing temperature at early age. The test results show that anti-freezing admixture have some problems due to high chloride content, which may cause the corrosion of reinforcement embedded in concrete. However, the mortar applied by accelerator and another kind of agent for enduring cold weather produced by S company lead to delay of strength development in low temperature. Also, it is clarified that there are no significant problems for cement mortar in strength development due to low temperature if a suitable kind of agent enduring cold weather is used and cement mortar is cured for more than $7.5^{\circ}D.D$ at early age.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.405-408
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• 2005

The repair and reinforcement materials of the concrete structure in underwater is use to epoxy mortar for underwater-harding. Because it ensures the separation of material and a fluidity in construction, it is important to epoxy mortar This study dealt with the influence of the using of rapidly-chilled steel slag on flow, nozzle passing time, viscosity, and strength of mortar by experimental design. As results of study, this paper proved that the more the using rate of rapidly chilled steel slag increased, the more this affected the enhancement of flow, the decrease of O-lot, and the development of compressive strength, flexural strength. Also, considering the fluidity, nozzle passing time and strength of mortar, it is desirable to use RCSS300 of rapidly chilled slag.