• 한국구조물진단유지관리공학회 논문집
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• 제18권1호
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• pp.84-92
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• 2014

본 연구는 조강시멘트와 경화촉진제를 사용하여 조기강도 발현의 메커니즘을 분석하는 것이 목적이다. 연구결과 경화촉진제는 시멘트와의 수화반응시 $Ca(OH)_2$의 촉진시키는 것을 TG/DTA 실험을 통하여 검정하였다. 압축강도 측정결과 경화촉진제의 사용량이 증가 할수록 초기압축강도가 증가하는 것을 알 수 있었다. 또한 미소수화열 측정결과 경화촉진제는 시멘트의 성분중 $C_3S$의 수화반응을 촉진시키는 것으로 나타났다. XRD분석결과 재령별 수화생성물을 확인할 수 있었으며 경화촉진제의 사용량이 증가할수록 수화물들의 피크점이 높게 나타나는 것을 알 수 있었다. SEM찰영을 한 결과 촉진제의 첨가량에 따라 $Ca(OH)_2$의 생성과 재령에 따라 C-S-H의 형상을 관찰할 수 있었다. 따라서 본 연구에서 사용된 경화촉진제는 초기강도발현 시키는 것에 대해 효과적인 것을 확인 할 수 있었다.

• 한국해양공학회지
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• 제18권4호
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• pp.46-51
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• 2004

The surface layer in dredged and reclaimed marine clay is improved by mixing of shallow soils and hardening agents, which is made of cement, containing some other special admixtures. Tests in both laboratory and field settings are performed to investigate the improvement effect and strength properties of cement-stabilized soils. The test results show that the hardening agent sufficiently improves the soil properties of the surface layer, while increasing the load-carrying capacity. The strength of cement-stabilized soils depends, primarily, on water-to-cement ratio and curing temperature. That is, the higher curing temperature and the longer curing time, the higher the strength in cement-stabilized soils. The high ratio of water-ta-cement results in a lower strength.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.75-76
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• 2023

In the cement industry, various research initiatives are underway to achieve carbon neutrality. Mineral carbonation is a technology that converts carbon dioxide into minerals for storage, and CO₂ reactive hardening cement is a type of cement that incorporates mineral carbonation technology. In this study, we aimed to manufacture CO₂ reactive hardening cement for reducing carbon emissions in the cement industry by utilizing waste concrete powder generated in the construction sector.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.80-81
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• 2013

There is the increasing number of constructing soil or structure on the soft ground during public works. Usually cement or slag cement has been the traditional material for surface soil stabilization method. Recently, early strength development properties of hardening agent is required for driving abilities of execution equipment and shortening of the construction time. Therefore, the purpose of this study is to develop the early compressive strength hardening agent for surface soil stabilization. The study was confirmed performance and availability of hardening agent using early strength type cement and industrial by-product minerals through early strength development properties in accordance with water cement ratio, content of hardening agent for soft soil.

• 한국세라믹학회지
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• 제12권2호
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• pp.21-25
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• 1975

As the major alumina source, domestic alunite was applied to synthesize the clinker for rapid hardening cement. The main minerals of the clinker were found to be C3S, C11A7-CaF2 and some C4AF by means of chemical treatment, x-ray diffraction analysis and microscopic observation. Rapid hardening cement was made of the clinker by adding suitable amount of hemi-hydrite and anhydrite. The setting time of the cement was regulated with citric acid as setter.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1992년도 봄 학술발표회 논문집
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• pp.23-28
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• 1992

In recent years, due to the construction boom the demand of cement is increasing suddenly and the use of imported cement is inevitable. But, because the quality of imported cement varies quite a lot, many problems have been encountered in construction fields. These problems include hardening retardation, lower early strength and crack of concrete. The object of this study is to explain causes for hardening retardation from a construction field case and propose a solution

• 한국산업융합학회 논문집
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• 제10권4호
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• pp.207-211
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• 2007

The durable lifetime of RC structures is shortened by various reasons, which are the generation of cracks in construction and service term, the exterior deterioration according to climatic condition, the surface damage due to chloride attack and the corrosion of reinforced bars. The durability of concrete structures is nevertheless able to be increased by the method and the material of reinforcement and repair. The epoxy resin is widely used for reinforment and repair of concrete because of the superiority in mechanical property, adhesive property, abrasion resistance, impact resistance and chemical resistance. The epoxy cement mortar with hardening agent has a lot of disadvantages that are troublesome mixing work, weakened weatherability and high cost for hardening agent. In this study, the mix proportion of mortar is presented just only with epoxy resin and some admixtures, and the test result of mortar without hardening agent shows the higher strength than the mortar with hardening agent. In the mix proportion, the weight of epoxy resin must be less than 15% of the unit weight of cement, and 10% of unit weight of cement is adequate for the weight of admixtures.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.153-158
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• 2001

The effects of polymer-cement ratio and shrinkage-reducing agent content on the durability characteristics of ultrarapid-hardening polymer-modified mortars using redispersible polymer powder are examined. As a result, the flexural and tensile strengths of the ultrarapid-hardening polymer-modified mortars using redispersible polymer powder tend to increase with increasing polymer-cement ratio, and tend to decrease with increasing shrinkage-reducing agent content. However, the compressive strength of the ultrarapid-hardening polymer-modified mortars using redispersible polymer powder decrease with increasing polymer-cement ratio and shrinkage-reducing agent content. And, water absorption and mass change of chemicals resistance of ultrarapid-hardening polymer-modified mortars using redispersible polymer powder tend to decrease with increasing polymer-cement ratio.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.56-58
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• 2013

In order to develop concrete generating compressive strength of 15MPa~30MPa aging for 6~12 hours in the room temperature curing, Hardening accelerator containing Ca²⁺ mixed with rapid hardening portland cement containing C₃S in quantity. The result was that the more addictive contents of Hardening accelerator is, the more greatly early compressive strength was improved. That s because the composition of Ca(OH)₂ was mass-produced at early-ages.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.413-416
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• 2005

The super early hardening cement is widely used for reducing construction period. But there are some problems with handling the cement because the loss of workability is so big to control. In this study, the fluidity properties of super early hardening cement paste was evaluated at early age of hydration by using gel-time determination method. 4 types of set controlling agent were selected and combinations of them were used for gel-time test. As a result, the gel-time of super early hardening cement paste was extended up to 20 minutes by using the combinations of several types set controlling agent.