• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.155-156
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• 2003

시멘트는 압축강도가 크고 내구성이 좋으며 가격이 저렴한 우수한 토목건축재료이다. 그러나 인장강도가 낮아서 사용 시 발생하는 휨에 의한 인장변형에 의하거나 양생 후 해 표면 크랙이 발생하는 결점이 있다. 이러한 결점을 보완하기위해 크랙의 발생 억제, 성장 지연을 목적으로 시멘트에 보강용 섬유를 투입하고 있다[1]. 시멘트에서의 보강섬유의 역할은 크랙발생에 필요한 에너지를 최대한 증가시키켜 시멘트가 경화되기 시작할 때, 구속에 의해 발생하는 인장응력 및 균열을 억제하구 내부에 형성되는 결함을 방지함에 있다[2]. (중략)

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.297-298
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• 2009

In this paper, it was to investigate different types of mortar properties using a chloride attack protection agent by evaluating mixing ratio of this particular agent, including 3% increments. The results showed that the compressive strength and chloride ion penetration resistance of mortar by using chloride attack protection agent were improved than non-added mortar.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.359-360
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• 2010

This study was performed an evaluation of physical & mechanical properties of mortar & concrete by fineness of slag cement. As the results of study, strength of mortar and concrete tended to improve as the fineness of slag cement increased and when considering early strength and 28days strength, the proper content fineness of slag cement was thought to be $5,000cm^2/g$.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.200-201
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• 2018

The purpose of this study is to evaluate the adhesion in tension of polymer-modified mortars according to curing conditions. From the test results, the adhesion in tension is seriously affected by type of curing conditions compared with type of polymer dispersions or polymer-cement ratios. The maximum adhesion in tension of EVA-modified mortar with polymer-cement ratio of 20% cured by standard condition is about 1.81 times, the cement mortar cured in water. It is apparent that the adhesion in tension of polymer-modified mortars according to raising of polymer-cement ratio is also much more improved irrespective of type of polymer dispersions and curing conditions.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.193-194
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• 2019

The purpose of this study is to design the basic mix proportions of antiwashout underwater polymer cement mortar as a repair material. The antiwashout underwater polymer cement mortars are prepared with various mix proportions using three type polymer dispersions without or with antifoamer. From the test results, the whole antiwashout underwater polymer cement mortars can be cast underwater without segregation like plain mortar. It is apparent that the flexural strength of antiwashout underwater SBR cement mortars with antifoamer at polymer- cement ratios of 5% and 10% is higher than that of plain mortar irregardless of a little low compressive strength.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.115-116
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• 2011

This study aimed at establishing the fundamental data needed to evaluate the applicability and practicability in using a bamboo activated carbon as a construction material. The experiment on the flow of mortars mixed with a bamboo activated carbon before the hardening was carried out for the evaluation of basic properties. The compressive and bending strength of mortar mixed with bamboo activated carbon after the hardening was measured. the thermal conduction rate and density were also measured. An comparative analysis on mortars mixed with pine charcoals was conducted to compare it with exiting materials.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.123-124
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• 2022

In this paper, the characteristics of slag cement mortar added with neutralized liquid red mud with sulfuric acid and reduced pH were reviewed to improve the strength degradation of cement concrete added with liquid red mud. As a result, in the case of compressive strength up to 7 days, the strength of the cement mortar added with liquid red mud tends to increase compared to Plain. This shows that adding liquid red mud to cement mortar tends to increase the initial age strength, and the compressive strength on the 28th shows 74% of Plain when adding non-neutralized liquid red mud and 89% when adding sulfate neutralized red mud. Therefore, it is judged that the compression strength is improved by neutralizing the liquid red mud with sulfuric acid.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.165-166
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• 2022

In this paper, the characteristics of slag cement mortar added with neutralized liquid red mud with nitric acid to reduce pH by neutralizing liquid red mud with nitric acid were reviewed to improve strength degradation of cement concrete added with liquid red mud. As a result, the compressive strength of cement mortar added with liquid red mud was higher than that of Plain on 1 and 3 days, and the strength of red mud neutralized with nitric acid was lower than that of cement mortar added with liquid red mud on 7 days, but the strength was recovered on 28th. It was found that the addition of red mud has the effect of improving the strength in the early age.

• Resources Recycling
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• v.28 no.6
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• pp.46-53
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• 2019

Cement mortar was hydrothermal-synthesized with particle size of tailings using scheelite tailings deposited without proper treatment, and its physical properties were investigated. The mixing ratios of water-cement and sand-cement were fixed at 75 % and 400 %, respectively, during preparing cemnt mortar, and the sand was replaced by the tailings at 0 ~ 50 %. The particle size of tailings was controlled at 9.3 ~ 53.0 ℃, and the hydrothermal temperature was kept at 60 ~ 180 ℃ for 6 hours after the temperature increased to pretermined temperature with 2 ℃ heating rate. The compressive strength increased with increasing hydrothermal temperature. The compressive strengths were 55.2 MPa and 54.5 MPa when the mortars were prepared with 30 % low arsenic and high arsenic tailings after 60 min grinding. The compresiive strenght was enhanced 300 % compared with reference sample.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.3
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• pp.75-83
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• 2012

Porosity in concrete has close relationship with durability characteristics. Additionally mixed water can help easy mixing and workability but causes increased porosity, which yields degradation of durability performance. In this paper, cement mortar samples with 0.45 of w/c (water to cement ratio) are prepared and durability performances are evaluated with additional water from 0.45 to 0.60 of w/c. Various durability tests including strength, chloride diffusion, air permeability, saturation, and moisture diffusion are performed. Then they are analyzed with changing porosity. Changing ratios and the patterns of durability performance are quantitatively evaluated considering pore size distribution, total porosity, and additional water content.