알칼리금속과 알칼리 토금속 촉매 담지 대나무 활성탄의 NO 가스 반응 특성

박영철 ( Young Cheol Bak ),최주홍 ( Joo Hong Choi ) 한국화학공학회 2016 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.54 No.5

The impregnated alkali metal (Na, K), and the alkali earth metal (Ca, Mg) activated carbons were produced from the bamboo activated carbon by soaking method of alkali metals and alkali earth metals solution. The carbonization and activation of raw material was conducted at 900 oC. The specific surface area and the pore size distribution of the prepared activated carbons were measured. Also, NO and activated carbon reaction were conducted in a thermogravimetric analyzer in order to use for de-NOx agents of the used activated carbon. Carbon-NO reactions were carried out in the nonisothermal condition (the reaction temperature 20~850 oC, NO 1 kPa) and the isothermal condition (the reaction temperature 600, 650, 700, 750, 800, 850 oC, NO 0.1~1.8 kPa). As results, the specific volume and the surface area of the impregnated alkali bamboo activated carbons were decreased with increasing amounts of the alkali. In the NO reaction, the reaction rate of the impregnated alkali bamboo activated carbons was promoted to compare with that of the bamboo activated carbon [BA] in the order of BA(Ca)> BA(Na)> BA(K)> BA(Mg) > BA. Measured the reaction orders of NO concentration and the activation energy were 0.76[BA], 0.63[BA(Na)], 0.77[BA(K)], 0.4 [BA(Ca)], 0.30 [BA(Mg)], and 82.87 kJ/mol[BA], 37.85 kJ/mol[BA(Na)], 69.98 kJ/mol[BA(K)], 33.43 kJ/mol[B (Ca)], 88.90 kJ/mol [BA(Mg)], respectively.

알칼리 자극제의 종류 및 첨가율에 따른무시멘트 경량 경화체의 강도특성

이상수,김윤미,박선규 한국건축시공학회 2014 한국건축시공학회지 Vol.14 No.4

본 연구는 포틀랜드 시멘트를 사용하지 않고 산업부산물인 고로슬래그를 기반으로 제지애시와 알칼리 자극제를 사용하여 기포를 발생시킴으로써 경량 패널의 심재 및 충전재등에 사용할 수 있는 무시멘트 경량 경화체를 개발하고자하였다. 이를 위하여 먼저 제지애시의 적정 치환율을 도출하기 위한 기초실험을 실시하였다. 기초 실험을 바탕으로 제지애시와 반응하여 수소기체를 발생시킬 수 있는 알칼리 자극제의 종류 및 첨가율에 따라 본 실험을 실시하였으며, 제조된 시험체를 대상으로 재령별 겉보기 밀도와 강도를 측정하였다. 그 결과 제지애시의 적정 치환율은 5%이며, 알칼리 자극제는 NaOH를 12.5% 첨가한 경화체의 겉보기 밀도가1.13g/㎤, 감소율 40.45%로 가장 낮은 겉보기 밀도를 나타내었으며, 겉보기 밀도와 비교하여 비교적 높은 강도를 발현하였다. 따라서, 알칼리 자극제로써 NaOH를 적정량 사용하고제지애시와의 반응시간을 늦출 수 있는 방법을 강구한다면보다 높은 강도와 경량성을 겸비한 무시멘트 경량 경화체를제조할 수 있을 것으로 판단된다. In order to reduce the emission of carbon dioxide(CO2), this research use blast furnace slag in concrete manufacture,as 100% replacement of cement. The aim of this study is to investigate the density and strength properties ofalkali-activated lightweight composites with alkali activators of different types and different amounts. The bubble forachieving the lightweight of alkali-activated lightweight composites was generated in the reaction between the paperash and the alkali activators instead of using a foaming agent. Lightweight formed concrete was conducted basicexperimental for determining replacement ratio of paper ash. Then, the density and strength were measured accordingto the types and the contents of the alkali accelerator that can react with the paper ash. As results, the optimumreplacement ratio of the paper ash was 5%. The alkali activator containing NaOH 12.5% obtained the lowest weightof 1.13g/㎤. Also, compressive strength were relatively high. Therefore, this study demonstrated that alkali acceleratorwith a certain amount of NaOH can achieve relatively high strength and lightweight alkali-activated lightweightcomposites.

알칼리 활성화제를 첨가한 페로니켈슬래그 혼입 삼성분계 콘크리트의 동결융해 저항성

조원정,박광필,안기용 한국건설순환자원학회 2022 한국건설순환자원학회 논문집 Vol.10 No.2

The present study assessed the micro structure and durability characteristics of ternary blended cement with different types of alkali activators. Ground granulated blast furnace slag(GGBS) and ferronickel slag(FNS) was replaced until 50 % of the weight o f cement. In a dditio n, p otassuim hydro xide a nd s o dium h ydro xide w ere used f o r comparing the pro perties o f different type of alkali activator. Ternary blended cement with alkali activators showed higher peak portlandite peak than that of OPC(Ordinary Portlande Cement) and non activated ternary blended cement. Also, there was no new hydration products in ternary blended cement or/and alkali activators. Based on the mercury intrustion porosimetry(MIP) test result, ternary blended cement increased macro pore while alkali activated ternary blended cement modified pore structure and increased microp pore as compared to OPC as control. Combination with alkali activators is desirable to enhance the compressive strength and freeze thaw resistance.

나트륨계 알칼리 활성화제를 사용한 친환경 알카리활성 슬래그 섬유보강콘크리트 보의 휨성능 평가

하기주,이동렬,하재훈 한국구조물진단유지관리공학회 2015 한국구조물진단유지관리공학회 논문집 Vol.19 No.2

In this study, it was developed eco-friendly alkali-activated slag fiber reinforced concrete using ground granulated blast furnace slag, alkali activator (water glass, sodium hydroxides), and steel fiber. Eight reinforced concrete beam using alkali-activated slag concrete were constructed and tested under monotonic loading. The major variables were mixture ratio of alkali activator, mixed/without of steel fiber. Experimental programs were carried out to improve and evaluate the flexural performance of such test specimens, such as the load-displacement, the failure mode, the maximum load carrying capacity, and ductility capacity. All the specimens were modeled in scale-down size. The reinforced concrete beams using the eco-friendly alkali-activated slag fiber reinforced concrete was failed by the flexure or flexure-shear in general. In addition, the maximum strength increased with the adding the mol of sodium hydroxide, and the specimen reinforced the steel fiber showed the value of maximum strength which is increased by 15.8% through 25.9%. It is thought that eco-friendly alkali-activated slag fiber reinforced concrete can be used with construction material and product to replace normal concrete. If there is applied to structures such as precast concrete member and production of 2nd concrete product, it could be improved the productivity and reduction of construction duration etc.

나트륨계 알칼리 활성화제를 사용한 친환경 알카리활성 슬래그 섬유보강콘크리트 보의 휨성능 평가

하기주,이동렬,하재훈 한국구조물진단유지관리공학회 2015 한국구조물진단유지관리공학회 논문집 Vol.19 No.2

In this study, it was developed eco-friendly alkali-activated slag fiber reinforced concrete using ground granulated blast furnace slag, alkali activator (water glass, sodium hydroxides), and steel fiber. Eight reinforced concrete beam using alkali-activated slag concrete were constructed and tested under monotonic loading. The major variables were mixture ratio of alkali activator, mixed/without of steel fiber. Experimental programs were carried out to improve and evaluate the flexural performance of such test specimens, such as the load-displacement, the failure mode, the maximum load carrying capacity, and ductility capacity. All the specimens were modeled in scale-down size. The reinforced concrete beams using the eco-friendly alkali-activated slag fiber reinforced concrete was failed by the flexure or flexure-shear in general. In addition, the maximum strength increased with the adding the mol of sodium hydroxide, and the specimen reinforced the steel fiber showed the value of maximum strength which is increased by 15.8% through 25.9%. It is thought that eco-friendly alkali-activated slag fiber reinforced concrete can be used with construction material and product to replace normal concrete. If there is applied to structures such as precast concrete member and production of 2nd concrete product, it could be improved the productivity and reduction of construction duration etc. 이 연구에서는 산업부산물인 알카리활성 슬래그와 알칼리 활성화제 (물유리, 수산화나트륨)에 강섬유를 사용하였으며, 이를 철근콘크리트 보에 적용하여 휨성능 평가를 하였다. 주요변수는 알칼리 활성화제의 혼입비율 및 강섬유를 혼입으로 총 8개의 실험체를 제작하였으며, 재료 및 구조성능 평가를 위한 실험을 수행한 결과 다음과 같은 결론을 얻었다. 친환경 알카리활성 슬래그 섬유보강콘크리트를 사용한 철근콘크리트 보는 전반적으로 휨 또는 휨-전단에 의하여 파괴되었다. 그리고 수산화나트륨의 몰 증가와 강섬유를 보강한 결과 최대내력이15.8~25.9% 증가한 값이 나타났으며, 연성 또한 높게 나타났다. 친환경 알카리활성 슬래그 섬유보강콘크리트는 기존의 콘크리트를 대체할수 있는 기초연구로서 향후 건설소재 및 재료분야에 활용할 수 있을 것으로 사료되며, 이러한 특성을 바탕으로 콘크리트 2차 제품 생산과구조부재를 PC화하여 활용할 경우 생산성 향상, 공기단축 등 효율이 상승될 것으로 보인다.

Mechanical Performance of Alkali-activated Stabilized Sandy Soil Reinforced with Glass Wool Residue Microfibers

Mohamad Kianynejad,Mohamad Mohsen Toufigh,Vahid Toufigh 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.2

Alkali-activated binders have been introduced as promising alternatives to conventional binders such as lime and ordinary Portland cement (OPC). However, alkali-activated materials exhibit a brittle behavior and crack formation due to tensile stresses is inevitable. To overcome these limitations, incorporation of fibers into the cementitious matrix is among the well-known techniques to improve the flexural behavior and energy absorption of the corresponding composites. The present study aimed to investigate the feasibility of using reinforced alkali-activated metakaolin as an alternative to common stabilizers to improve the engineering characteristics of sandy soil. Calcium carbide residue (CCR) was used as an alkali activator, and glass wool residue (GWR) microfibers were used as reinforcement elements to maximize waste stream utilization. Unconfined compressive strength (UCS), California bearing ratio (CBR), and three-point bending tests were performed to evaluate the mechanical behavior of the alkali-activated products. Moreover, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were employed to determine the microstructure and elemental composition of these products. The results indicate that the compressive strength and ductile behavior of the stabilized soil samples improved significantly. Furthermore, the SEM/EDX analysis of the reinforced alkali-activated samples revealed the interfacial bond between the microfibers and alkali-activated binding gel, enhancing the mechanical performance between the microfibers and cementitious matrix.

알칼리 활성 슬래그 콘크리트의 내구성: 콘크리트의 염소이온 확산

홍기남 ( Ki Nam Hong ),박재규 ( Jae Kyu Park ),정규산 ( Kyu San Jung ),한상훈 ( Sang Hun Han ),김재현 ( Jae Hyun Kim ) 한국안전학회(구 한국산업안전학회) 2015 한국안전학회지 Vol.30 No.4

The aim of the present study is to investigate some characteristics of concrete according to addition of blast furnace slag and alkali-activator dosages. Blast furnace slag was used at 30%, 50% replacement by weight of cement, and liquid sulfur having NaOH additives was chosen as the alkaline activator. In order to evaluate characteristics of blast furnace slag concrete with sulfur alkali activators, compressive strength test, total porosity, chloride ions diffusion coefficient test were performed. The early-compressive strength characteristics of blast furnace slag concrete using a sulufr-alkali activators was compared with those of reference concrete and added 30, 50% blast furnace slag concrete. Also, Blast furnace slag concrete using sulfur-alkali activators enhanced the total porosity, chloride ions diffusion coefficient than two standard concrete. Alkali-activated blast furnace slag concrete was related to total porosity, compressive strength and chloride ions diffusion coefficient each others. As a result, it should be noted that the sulfur-alkali activators can not only solve the demerit of blast furnace slag concrete but also offer the chloride resistance of blast furnace slag concrete using sulfur alkali activators to normal concrete.

수산화나트륨으로 알카리활성화한 Fly ash 시멘트의 강도특성

박상숙 ( Sang-sook Park ),강화영 ( Hwa-young Kang ) 한국환경기술학회 2004 한국환경기술학회지 Vol.5 No.3

본 연구의 목적은 화력발전소에서 배출되는 Fly ash를 수산화나트륨용액으로 활성화 할 경우 Fly ash의 반응성 개선으로 기존 포틀랜트시멘트를 대체할 수 있는지를 평가하였다. 활성화제의 농도(NaOH 2M에서 10M), 물과 fly ash의 비율 그리고 fly ash/모래의 혼합 비율을 달리하여 연구를 수행하였다. 알칼리 활성화된 fly ash로 제조한 시편의 압축강도는 30℃에서 하루동안 양생 후 탈형 한 다음 90℃ 건조기에서 재령 4일에 측정하였다. 8M의 NaOH 농도를 가진 활성화용액 50%와 160%의 fly ash를 혼합하여 제조한 AAF(Alkali Activated Fly ash)의 압축강도는 127kg/㎠로 나타났다. 10M의 NaOH 농도를 가진 활성화용액 40%, fly ash 60% 그리고 150%의 모래를 혼합하여 제조한 AAFS(Alkali Activated Fly ash and Sand)의 압축강도는 113kg/㎠로 나타났다. 이들 조건하에서 제조된 AAF와 AAFS는 시멘트 벽돌의 허용압축강도를 50kg/㎠ 이상으로 규정하는 KS의 조건을 충족시키므로 활성화된 fly ash는 포틀랜트시멘트를 대신할 수 있을 것이다. 더욱이 20%의 염산에 90일간 침지시킨 AAF와 AAFS의 무게손실이 5%인 것을 감안하면 산에 대한 저항성이 극적으로 개선되었음을 알 수 있다. The purpose of this study is to evaluate the potentials for substituted portland cement result from improved the reactivated in case of the activation of fly ash produced from coal-fired power plant with NaOH solution. The parameters of process studied are: different activator concentration(NaOH 2M to 10M), water-to fly ash ratios, and fly ash-to sand ratios. The compressive strength of the specimens manufactured using alkali-activated fly ash was measured of cured at 1day, 25℃ and at 4 days of reaction, 90℃. AAF(Alkali Activated Fly ash) mixture 50% activating solution with 8M NaOH and 160% fly ash develop compressive mechanical strengths of 127 kgf/㎠. AAFS(Alkali Activated Fly ash and Sand) mixture 40% activating solution with 10M NaOH, 60% fly ash and 150% sand develop compressive mechanical strengths of 113 kgf/㎠. The AAF and AAFS manufactured under this conditions have high compressive strength above KS for cement brick(50 kgf/㎠), therefore, activated fly ash can be used substituted for portland cement. Moreover, AAF and AAFS that took place during exposure to 20% concentration of hydrochloric acid-5% weighe loss in 90 days dramatically shows the improved acid resistance.

알칼리자극제 및 고로슬래그미분말을 병용한 에폭시수지 혼입 폴리머 시멘트 모르타르의 성질

김완기 ( Wan-ki Kim ) 한국구조물진단유지관리공학회 2021 한국구조물진단유지관리공학회 논문집 Vol.25 No.1

본 연구는 액상폴리머인 에폭시수지를 이용한 고내구성 폴리머 시멘트계 재료를 개발할 목적으로 고로슬래그미분말 치환율을 20%로 고정하고, 4종류의 알칼리 활성화제를 이용한 경화제 무첨가 에폭시수지 혼입 폴리머 시멘트 모르타르를 제작하여, 강도 특성, 에폭시수지 경화도, 흡수율, 내황산성, 중성화 및 염화물이온 침투저항성을 검토한 것이다. 그 결과, 알칼리 자극제의 종류에 관계없이, 고로슬래그미분말 20%를 사용한 경화제 무첨가 EMM의 압축강도는 폴리머 결합재비 10%에서 최댓값을 나타냈으며, 폴리머 결합재비 20%에서는 에폭시수지의 경화도 감소와 함께 압축강도 또한 감소하는 것으로 나타냈다. 휨강도는 압축강도와 마찬가지로 수산화칼슘을 첨가한 것이 가장 우수하게 나타났으며, 폴리머 결합재비의 증가와 함께 증가하였으며, 모두 9.0 MPa 이상의 휨강도를 발현하였다. 알칼리 자극제의 종류에 관계없이, 경화제 무첨가 EMM의 방수성, 중성화 및 염화물이온 침투저항성은 폴리머 결합재비의 증가와 함께 현저히 개선되었으며, 4종류의 알칼리 자극제 가운데 수산화칼슘을 첨가한 모르타르가 가장 우수한 것으로 나타났다. 한편, 알칼리 자극제의 종류에 관계없이, 경화제 무첨가 EMM의 내황산성은 폴리머 결합재비의 증가와 함께 떨어졌는데, 이것은 폴리머 결합재비의 증가에 따른 에폭시수지의 미경화 에폭시수지의 증가에 기인한 것으로 판단된다. 4가지 알칼리 자극제의 종류에 대하여 물성 및 내구성을 비교 검토한 결과, 수산화칼슘을 첨가한 것이 가장 우수한 것으로 확인되었다. The purpose of this study is to investigate the properties of hardener-free epoxy-modified mortars(EMMs) using ground granulated blast furnace slag(GGBFS) and alkali activators. The hardener-free EMMs with a GGBFS content of 20% using 4 types of alkali activators were prepared with various polymer-binder ratios, and tested for strengths, water absorption, carbonation depth, chloride ion and H₂SO₄ penetration depth. The conclusions obtained from the test results are summarized as follows: The compressive strength of the EMMs with a GGBFS content of 20% attains a maximum at a polymer-binder ratio of 10%. The flexural strength of the hardener-free EMMs using Ca(OH)₂ as a alkali activator is improved with increasing polymer-binder ratios. However, the flexural strength of the EMMs using NaCO₃, Na₂SO₄ and Li₂CO₃ is gradually decreased with increasing polymer-binder ratios. Regardless of the type of alkali activator, the water absorption, chloride ion penetration and carbonation depth are remarkably decreased with increasing polymer-binder ratios due to the epoxy film formed in the EMMs. The H₂SO₄ penetration depth of the hardener-free EMMs with a GGBFS content of 20% is gradually increased with increasing polymer-binder ratio. In this study, the properties of hardener-free EMMs using Ca(OH)₂ as a alkali activator are more excellent than those of other alkali activators.

석고가 첨가된 슬래그 기반 알카리활성 모르터의 압축강도 및 건조수축 변형률

양근혁,심재일 한국건축시공학회 2008 한국건축시공학회지 Vol.8 No.1

Twelve mortars were mixed and tested to explore the effect of gypsum on the compressive strength development and shrinkage strain of alkali-activated mortars. Powder typed sodium silicate and ground granulated blast-furnace slag were employed as alkaline activator and source material, respectively, to produce cementless mortar. The main variables investigated were alkali quality coefficient combining the concentration of activator and main compositions in source material, and the adding amount of gypsum ranged between 1 and 5% with respect to the weight of binder. Initial flow, compressive strength development, modulus of rupture, and shrinkage strain behavior of mortar specimens were measured. In addition, the hydration production of alkali-activated pastes with gypsum was traced using X-ray diffraction and energy-dispersive X-ray analysis combined with scanning electron microscope image. Test results showed that the initial flow of slag-based alkali-activated mortar was little influenced by the adding amount of gypsum. On the other hand, the effect of gypsum on the compressive strength of mortar specimens was dependent on the alkali quality coefficient, indicating that the compressive strength increased with the increase of the adding amount of gypsum until a certain limit, beyond which the strength decreased slowly. Shrinkage strain of mortar tested was little influenced by the adding amount of gypsum because no ettringite as hydration product was generated. However, the adding of gypsum had a beneficial effect on reducing the microcrack in the alkali-activated mortar.