This study examines the strength properties use of talc as a substitute for OPC-GGBFS cement. The test was carried out by replacing the plain mix(OPC : GGBFS = 50 : 50) with talc at the rate of 0~100%. The OPC contents was constant in all mixtures. The mixtures replaced GGBFS with talc. The results showed that the compressive strength and bending strength decreases with an increase in talc contents.

알칼리활성화 슬래그-레드머드 시멘트는 알칼리활성화 시멘트 연구의 일환으로서 시멘트 조성에서 알칼리자극제, 고로슬래그와 레드머드로 구성되어져 있으며, 포틀랜트 시멘트를 사용하지 않는 클링커 프리 시멘트(Clinker Free Cement)를 의미한다. 본 논문에서는 포틀 랜트 시멘트를 전혀 사용하지 않고 고분자 유기화합물인 재유화형 분말 폴리머를 혼입한 알칼리활성화 슬래그 시멘트에 레드머드의 대체율을 달리하여 강도특성, 기공특성 등을 기존 포틀랜트 시멘트와 비교 평가하였다. 그 결과 알칼리활성화 시멘트에 레드머드를 대체할 경우 C-S-H 광물상과 에트린가이트가 주요 수화생성물로 포틀랜트 시멘트와 비교하여 조직이 치밀하고 대체율 10%까지는 압축강도 및 휨강도가 증가하 였다.

This study evaluated the standard consistency, setting time, hydration heat, and compressive strength of binary blended cement concrete (general and high strength) using air cooled ladle furnace slag (LFS) of 3, 5, 7, 10wt.% as an admixture for ordinary portland cement (OPC). Results showed that binary blended cements using the LFS of lower than 5wt.% shortened the setting time and reinforced the compressive strength of concrete (general and high-strength) compared to OPC concretes although binary blended cements needed more water to achieve the standard consistency. This indicated that LFS could be used as a useful admixture for manufacturing binary blended cement. Thus, we expected that the upcycling of LFS would be contributed to save energy consumption and reduce the greenhouse gas emission from the field of cement industry.

Reaction degree of ground granulated blast furnace slag(GGBFS) in cement paste was measured by water-binder ratio and GGBFS replacement ratio, curing temperature with ages using selective dissolution. In result of experimental, when water-binder ratio and curing temperature were high and replace ratio of GGBFS was low, reaction degree was estimated high.

This study investigated the effect of cement type and ground granulated blast furnace slag (GGBS) on the mechanical properties and workability of grout for offshore PSC structures. As the replacement ratio of GGBS increased, the flowability of the grout increased and both intial and final setting times of grout was delayed regardless of cement type. However, the effects of GGBS on the bleeding of grout were different according to the type of cement: as the ratio of GGBS increased, less bleeding was observed for the grout with typeⅠ cement whereas higher bleeding was generated for the grout with type Ⅲ cement. However, there was no significant difference in their compressive strength at 28 day according the different replacement ratio of GGBS from 0 to 40%.

본 연구는 환경부하 저감을 위해 슬래그 시멘트를 사용하고 플라스틱 섬유보강재(폴리프로필렌, 나일론, 유리섬유)를 혼입하여 고강도 간격재를 개발하고 현장적용성을 평가하는 연구이다. 이를 위해 예비실험을 통하여 4가지 섬유 복합재의 첨가량이 결정되었다. 또한 역학적 시험(압축, 휨, 인장) 및 내구성 시험(흡수율, 투수율, 길이변화율, 균열저항성, 탄산화, 동결융해)을 통하여 최적의 섬유재를 도출하였으며, 이를 이용한 고강도 섬유재 간격재의 배합 및 생산시스템을 개발하였다. 또한 현장적용성 평가를 통하여 개발된 간격재의 구체 콘크리트 일체성을 확인하였다.

본 연구는 수산화나트륨(NaOH)으로 활성화된 알칼리 활성화 슬래그 시멘트(alkali-activated slag cement; AASC)의 기초 특성에 관한 실험에 관한 연구이다. 물-결합재 비(W/B)를 0.4와 0.5로 하였다. 그리고 활성화제의 농도를 2M과 4M을 사용하였다. 각 W/B 비에 대해5가지의 배합을 고려하였다. N0는 KS L 5109의 방법이고 N1~N4는 배합시간, 배합 단계 그리고 잔골재의 투입시점을 다르게 변화시켰다. 시험결과 AASC의 플로우 값, 강도 그리고 건조수축은 잔골재의 투입시점에 영향을 받았다. 플로우 값은 잔골재의 투입시점이 늦춰짐에 따라 감소하는 경향을 나타내었다. 압축강도와 휨강도는 투입시점이 늦어짐에 따라 증가하였다. 더구나 XRD 분석은 이러한 결과들을뒷받침하고 있었다. 건조수축은 잔골재의 투입시점이 늦어지면 증가하였다. 본 연구에 고려된 실험요인들을 통해 배합을 조절한다면 AASC의 특성을 향상시킬 수 있을 것이다.

In this study, it was developed eco-friendly zero cement fiber reinforced concrete using ground granulated blast furnace slag and alkali activator(water glass, sodium hydroxides). Also, it was evaluated the flexure capacity of the RC beams using zero cement concrete. The eco-friendly concrete using zero cement encouraged alkali activation reaction has rapid hardening speed and showed possibility as a high strength concrete. Also, the RC beams applied this showed similar movement and destroy tendency with RC used previous cement.

In this study, manufactured of cement mortar using high early strength cement(10 ~ 50 wt%) and blast furnace slag powder(50 ~ 90 wt%), according to compressive strength and flexural strength of hardened cement mortar. XRD and SEM were evaluated utilizing the initial cement hydration properties.

Comparing with using ordinary Portland cement, using blast furnace slag as binder in concrete shows low resistance for carbonation phenomenon. In this research, we focus on carbonation of high volume blast furnace-blended concrete, analysis the reason and find a more efficient method which comparing with using ordinary Portland cement, using FC shows better effort on concrete carbonate resistant.

In this study, “Recycling of ladle furnace slag (LFS) in the electric furnace process to produce ultra rapid harding cement” is the target technology. Environmental and economic efficiencies of target technology are analyzed and ecoefficiency is assessed based on these results. The methodologies to analyze environmental and economic efficiencies are LCA (Life Cycle Assessment) and market price which is calculated based on LCC (Life Cycle Costing), respectively. Global warming potential (GWP) and abiotic resource depletion (ARD) are selected as indicator of environmental analysis. The reference flow of this study is considered 1kg of ultra rapid harding cement which made from the LFS. As a result of that, target process has environmental efficiency of 13.1 for global warming and 5.93 for abiotic resource depletion and has economic efficiency of 4.86. Eco-efficiencies are derived from this study can be applied to slag recycling policy formulation and effect analysis in the future. This can be also applied to improve process’s environmental and economic performances.

This study investigates the fundamental properties of the water-binder (W/B) ratio and fine aggregate-binder (F/B) ratio in the alkali-activated slag cement (AASC) mortar. The W/B ratios are 0.35, 0.40, 0.45, and 0.50, respectively. And then the F/B ratios varied between 1.00 and 3.00 at a constant increment of 0.25. The alkali activator was an 2M and 4M NaOH. The measured mechanical properties were compared, flow, compressive strength, absorption, ultra sonic velocity, and dry shrinkage. The flow, compressive strength, absorption, ultra sonic velocity and dry shrinkage decreased with increases W/B ratio. The compressive strength decreases with increase F/B ratio at same W/B ratio. Also, at certain value of F/B ratio significant increase in strength is observed. And S2 (river sand 2) had lower physical properties than S1 (river sand 1) due to the fineness modulus. The results of experiments indicated that the mechanical properties of AASC depended on the W/B ratio and F/B ratio. The optimum range for W/B ratios and F/B ratios of AASC is suggested that the F/B ratios by 1.75~2.50 at each W/B ratios. Moreover, the W/(B+F) ratios between 0.13 and 0.14 had a beneficial effect on the design of AASC mortar.

These researchers are studying on the hydration model suggestion of cement incorporating blast furnace slag in durability prediction of concrete using hydration model. So in this study it measured hydration heat according to replace ratio, water cement ratio using conduction calorimeter to acquire experiment data for experimental verification and verify hydration heat property when blast furnace slag is incorporated.

This study examines the strength development of non cement binder using blast furnace slag, which is generated as a by-product in the manufacturing the irons. In the experiment, we used KOH, Ca(OH)2 as the blast furnace slag stimulus. As the results of this experiments, it was shown that the compressive strength increased when mixing ratio of KOH and Ca(OH)2 was increased.

This paper presents the experimental results for durability of an NaOH designed with blast furnace slag through the test method of chloride ion resistance and freezing-thawing resistance, Carbonation. In order to compare with NaOH, normal concrete was also tested. Test results showed that NaOH exhibited lower durability performance than ordinary mortar.

In previous research, it was found that waste oil was effective on resisting carbonation of concrete. This study is to find the effect of waste oil on the fundamental properties of concrete when blast furnace slag with high volume is used as a partial replacement of cement. Test results showed that the addition of waste oil in the concretes decreased slump and air content, but further reduction was not observed as the amount of the waste oil further increased. In addition, the waste oil had a little impact on deteriorating the compressive strength of the concretes.