In this study, high-ductile and low-fiber composites have been mixed using Alkali-activated cement-free binders combined with PVA fibers of the volume fraction of 1.0～1.5%. From the direct tensile test of the composites, the low-fiber cement-free composites could exhibit high-ductile tensile behaviors about 4.0～7.0% tensile strains after cracks.

최근 환경문제가 이슈화됨에 따라 건설폐기물의 재활용과 순환자원의 사용을 확대해 나가고 있다. 이에 순환자원과 무시멘트 알칼리 활성제를 사용한 지오폴리머에 대한 연구를 실시하였다.

The present study concerns the properties of cement-free concrete using binding capacity of cement paste. The cement-free was casted with alkali-activators(KOH, NaOH, and CaOH2) by weight of binder. The properties of cement-free concrete was studied compare to that of OPC. It was found that an increase in the chloride concentration resulted in a decrease the binding capacity of OPC.

The purpose of this study is to investigate the characteristics of compressive strength and workability according to the NaOH and KOH addition method as powder of mortar which is made of Non-sintered binder for the reuse of resources and the CO2 reduction

In present study, leaching alkali ions in concrete are measured to inhibition of effect to binder(OPC, GGBS, Loess) at 100 days. As a result, OPC concrete was measured the value of pH 9.15 and GGBS concrete was showed the value of pH 8.61.

This study is the basic experiment for manufacturing non-cement matrix of lightweight based on blast furnace slag. Consequently, the decrease ratio of the density of matrix about the density of mix showed Ca(OH)2 up to be the highest when adding 2.5%. And the compressive strength increased as the addition ratio of Ca(OH)2 was increased.

This study was carried out to evaluate effects of curing method and age on compressive behavior of steel fiber reinforced Alkali-Activated Slag(AAS) concrete. AAS and Steel Fiber Reinforced Concrete (SFRC) material with specific compressive strength of 30MPa was reinforced with 0% to 1% steel fibers at the volume fraction. Two types of curing methods were used: water curing and exposed curing. Curing time is 3, 7, 28 day. Experimental results indicated that compressive strength, elastic modulus, compression index.

The purpose of this study is to estimate basic mechanical properties of steel fiber reinforced Alkali-Activated Slag(AAS) concrete. Principle variable is the fiber volume fraction: 0, 0.5, 1%. Two type cement composites were used: Steel Fiber Reinforced Concrete(SFRC) and AAS. Mechanical properties of AAS concrete and SFRC, including compressive strength, elastic modulus, flexural strength, splitting tension.

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.

감마선이 조사된 세포막 모델에서 K+ 와 Na+의 선택적 전달특성을 연구하였다. 이 실험에 사용된 세포막 모델은 Na+슬폰화 폴리스티렌-디비닐벤젠(polystyrene-divinylbenzene) 혼성 중합막을 사용하였다. 이온의 초기플럭스는 H+이온 농도의 증가와 함께 증가하였다. 이 실험의 조건을 pH 0.5-3, 온도 15-65℃로 하여 첫 번째 조사되지 않은 막의 K+와 K+/Na+의 선택도는 약 1.06 - 1.13이고 두 번째 조사된 막의 K+와 K+/Na+의 선택도는 약 0에 가깝다. 조사된 막의 pH의 추진력은 조사되지 않은 막보다 약 4-5배 정도 유의성 있게 증가하였다. 세포막모델에서 K+ 와 Na+의 선택적 전달특성이 비정상적이기 때문에 세포장해가 세포에서 발현된다.

본 연구는 알칼리 활성화 슬래그에서 혼합 활성화제에 관한 것이다. 본 연구에서는 수산화나트륨(NaOH, A Case), 수산화칼슘(Ca(OH)2, B Case), 수산화마그네슘(Mg(OH)2, C Case), 수산화알루미늄(Al(OH)3, D Case), 그리고 수산화칼륨(KOH, E Case)의 5가지 수산화계열 활성화제를 사용했다. 이 5가지 수산화계열 활성화제와 탄산나트륨(Na2CO3)를 혼합하였다. 5가지 수산화계열 활성화제의 농도는 3M로 하고, 탄산나트륨은 1M, 2M, 3M로 하였다. 플로우와 응결 특성은 탄산나트륨의 혼합에 따라 감소하는 결과가 나타났다. 그러나 압축응력은 탄산나트륨의 혼합 농도에 따라 증가하는 결과를 나타내었다. 이것은 수산화계열 활성화제와 탄산나트륨의 혼합은 알칼리 활성화 슬래그 모르타르의 특성에 효과적인 것으로 판단된다.

This paper reports test to assess the influence of water/solid on the compressive strength of fly ash based alkali activated concrete. According to test results, the strength is influenced by the waste/solid. Also, the appropriate Ms(SiO2/Na2O) rate is thought to be 1.0.

Investigated the factors to effect on the flow of geopolymer mortar based on on ground granulated blast furnace slag in order to develop cementless alkali-activated concrete GGBS.

본 연구는 수산화나트륨(NaOH)으로 활성화된 슬래그 모르타르에 석고를 혼합하여 플로우, 응결시간 및 압축강도에 미치는 영향을 알아보고자 하였다. 실험에는 석고를 슬래그 중량에 대해 0~50%까지 혼합하고, 활성화제의 농도는 3M와 6M, 양생온도는 20±2℃와 35±2℃의 경우에 대해 실시하였다. 플로우와 응결시간시험결과는 석고의 혼합률이 증가할수록 증가하였다. 그러나 압축강도는 일정 혼합률까지 석고의 첨가량이 증가하면 증가하지만 그 이후로는 감소하였다.

The object of this research is to confirm the effect of Waste Glass Sludge on properties of concrete through compressive strength and Alkali-Silica reaction of concrete and to develop as construction material.

Limestone powder can be used for concrete as a partial replacement of Portland cement so that concrete becomes more environment-friendly construction material. One of the great applications of limestone powder added cement concrete might be a cement concrete pavement since the concrete pavement consumes massive quantity of Portland cement. However, it has been reported recently that Alkali-Silica Reaction (ASR) occurs on the cement concrete pavement causing a serious damage. This study investigates the resistance of limestone powder added cement mortar to ASR. The mortar used very high reactive silicious aggregate for accelerated ASR. Experimental procedures followed ASTM C 1260 and variables included different replacement levels of limestone powder in the mortar mix.

To clarify the load-carrying behavior of RC beams caused by the rebar fracture and the expansive crack along the longitudinal reinforcement due to aggregate expansion simulating ASR, experimental study was carried out. From the test result, all specimens caused by the rebar fracture failed in shear tension. Moreover, cracking behavior and crack propagation highly influenced by the range of expansive crack.

In this study, the alkiline water washing condition of mackerel(Scomber japonicus) dark meat was investigated to improve processing conditions of red muscle fish meat paste heating gel. Chemical alkaline water(CWM) and electrolytic alkiline water(EWM, pH 12) were used for washing the mackerel raw meat. Washed meats were minced with 2.5% salt and heated at 90℃/15 min to testing texture profile analysis. Moisture of CWM and EWM was increased with both washing times(p<0.05). Crude lipids and protiens were decreased with washing times. Lightness of chemical alkaline water washed mackerel heated paste gel(CWHPG) was higher than electrolytic alkaline water washed mackerel heated paste gel(EWHPG). Redness and yellowness were more decreased than control meats. Jelly strength of CWHPG and EWHPG was not increased more than 2 times wased meat and was increased with protein decrease. Texture profile analysis, max force1 of CWHPG and EWHPG was higher hardeness than the control meat except gel strains. From these results, it could be suggested that electric alkialine water washing is also effective in advance the red meat paste heating gel process of kamaboko industry.

철을 포함한 비정질 규산염 용융체의 원자 구조 규명은 지표 환경의 화성활동 및 맨틀 심부의 초저속도층의 속도구조에 이르는 광범위한 지질과정의 미시적인 원인에 대한 단서를 제공한다. 본 연구에서는 철을 포함한 비정질 규산염의 원자 구조 규명에 가장 적합한 고상 핵자기공명분광분석(NMR)을 이용하여 최대 16.07 wt%의 Fe2O3가 포함된 비정질 알칼리 규산염(iron-bearing alkali silicate glasses)의 철의 함량 변화가 원자구조에 미치는 영향을 규명하였다. 29Si 스핀-격자 완화시간(T1)을 측정한 결과, 철의 함량에 따라 스핀-격자 완화시간이 짧아지는데 이는 철이 가지고 있는 홀전자(unpaired electron)와 핵 스핀(nuclear spin)간의 상호작용으로부터 기인한다. 29Si MAS NMR 실험 결과, 철이 포함되지 않은 시료의 경우 Q2, Q3 그리고 Q4의 환경을 지시하는 피크가 분리됨에 반하여, 철이 포함된 시료의 경우 NMR 신호의 급격한 감소와 피크 폭이 넓어짐으로써 각각의 규소 환경이 거의 분리되지 않았다. 그러나 철의 함량에 따라 스펙트럼이 넓어지고 화학적 차폐값(chemical shift)이 높아지는 현상을 확인하였는데, 이는 Q4의 규소 환경을 나타내는 방향으로서 철 주변의 Qn이 불균질하게 분포하고 있음을 지시한다. 17O MAS NMR 실험에서도 철이 포함되지 않은 시료에서는 연결산소(Si-O-Si)와 비연결산소(Na-O-Si)가 부분적으로 분리되지만, 철의 함량이 증가하면서 각각의 산소 환경이 거의 분리되지 않는다. 이러한 연구결과는 고상 핵자기공명분광분석이 철을 포함한 비정질 규산염의 상세한 구조 연구에 효과적인 도구임을 지시한다.

Since biodiesel as bioenergy is defined as ester compounds formed by esterification of animal/vegetable oils, in this study three vegetable cooking oils (market, waste and refined waste ones) were esterified by reactions of alkali catalyst and immobilized enzyme. The fatty acid composition of the formed ester compounds was analyzed to investigate the feasibility of biodiesel production. By lipolysis (i.e, hydrolysis of Triglyceride (TG)), all three vegetable oils used in this study were found to produce Diglyceride (DG), Monoglyceride (MD) and Fatty acid ethylester (FAEE). However, the amount of produced FAEE (which can be used as an energy source) was in the increasing order of market cooking oil, waste one and refined waste one. With NaOH catalyst, FAEE was produced about 24.92, 17.63 and 11.31 % for the respective oils while adding Lipozyme TL produced FAEE about 43.54, 38.16 and 24.47 %, respectively. This indicates that enzyme catalyst is more effective than alkali one for transesterification. In addition, it was found that the composition of fatty acids produced by hydrolysis of TG was unchanged with alkali and immobilized enzyme reactions. Thus it can be expected that stable conditions remain in the course of mixing with gasoline whose composition is similar to that of the fatty acids.