초록 ▼

최근 전세계적으로 온실가스 증가와 기후변화 문제에 대한 관심이 급증함에 따라 우리나라도 온실가스 감축을 위해 배출량 저감 목표를 세우고 목표 달성을 위해 온실가스 저감기술을 적극적으로 개발하고 있다. 온실가스 중에서는 대표물질로 알려져있는 이산화탄소 뿐만 아니라 질소산화물 또한 문제가 되고 있는데, 자동차 등의 도로이동오염원과 산업용 보일러나 발전설비와 같은 고정원에서 배출되는 질소산화물(NOx)은 유해 대기오염물질로써, 호흡기계의 병을 일으킴은 물론 스모그와 산성비의 원인이 되는 가스성분이라는 것은 잘 알려져 있다. 이러한 도로이

최근 전세계적으로 온실가스 증가와 기후변화 문제에 대한 관심이 급증함에 따라 우리나라도 온실가스 감축을 위해 배출량 저감 목표를 세우고 목표 달성을 위해 온실가스 저감기술을 적극적으로 개발하고 있다. 온실가스 중에서는 대표물질로 알려져있는 이산화탄소 뿐만 아니라 질소산화물 또한 문제가 되고 있는데, 자동차 등의 도로이동오염원과 산업용 보일러나 발전설비와 같은 고정원에서 배출되는 질소산화물(NOx)은 유해 대기오염물질로써, 호흡기계의 병을 일으킴은 물론 스모그와 산성비의 원인이 되는 가스성분이라는 것은 잘 알려져 있다. 이러한 도로이동오염원에서 NOx에 의한 대기오염을 극복할 수 있는 방안이 사회적으로 요구되고 있는 실정이다. 현재까지 무시멘트 콘크리트 분야에서 탄소 저감을 위해 연구된 분야는 시멘트 사용량을 줄임으로써 시멘트 생산 시에 발생하는 CO₂ 배출량을 줄이는 수동적인 탄소 저감에 치중되어있다. 시멘트 대체용으로 연구 및 활용은 되고 있으나, 이들 소재를 활용한 콘크리트의 이산화탄소 흡수에 관해서는 아직 밝혀진 바가 없다. 따라서 2-1-1세세부에서는 재료 사용량을 줄임으로 인한 탄소 저감과 동시에 산업부산물을 이산화탄소 흡수제로 활용함으로써 능동적인 탄소 저감을 동시에 얻고자 한다. 2-1-2세세부에서는 NOx에 의한 대기오염을 저감할 수 있는 방안으로써, 콘크리트 재료에 광촉매(TiO₂) 소재를 적용하여 유해가스 제거기능이 부여된 친환경 광촉매 콘크리트 공법을 개발하고자 한다.

Abstract ▼

Ⅲ. Research & Development Tasks and Results
(1) Development of Concrete Materials for the Effective Carbon Capture and Sequestration using Recycled Industrial Wastes
⚪ Investigate the type and status of industrial by-products and supply and demand in domestic, and check recycling and disposal

Ⅲ. Research & Development Tasks and Results
(1) Development of Concrete Materials for the Effective Carbon Capture and Sequestration using Recycled Industrial Wastes
⚪ Investigate the type and status of industrial by-products and supply and demand in domestic, and check recycling and disposal status of industrial by-products are mainly used
⚪ Check the type of mainly binder and activator for manufacture of carbon dioxide absorbent by existing studies
⚪ Blast-furnace slag as the main binder was used, and NaOH and Ca(OH)₂ were utilized as the activator for the production of the concrete
⚪ Pulverized a alkali-activated blast-furnace slag paste and mortar were packed in the column, and then a gas stream containing CO₂ at 5000 ppm was introduced. The influent and effluent concentrations of CO₂, by which the amount of CO₂ absorbed was calculated.
⚪ The changes of surface morphology and chemical composition before and after the carbon dioxide absorption were analyzed by SEM and XRF.
⚪ The compressive and flexural strength of mortar and concrete were measured on Exposure to carbon dioxide conditions.
The following tasks were performed to develop each system.
⚪ Activator concentration more then 20%, the Alkali Activated blast furnace slag, (AABFS) absorbed approximately 42 g of carbon dioxide per mass of paste.
⚪ Meanwhile the amount of carbon dioxide absorbed onto OPC was minimal at the same activator concentration condition, indicating that the AABFS actively absorbed carbon dioxide by the carbonation reaction on its surface.
⚪ However, the carbon dioxide absorption capacity and rate decreased with increasing the activator concentration, because the activator at the high concentration promoted the hydration reaction and formed a dense internal structure, which was confirmed by the SEM analyses.
⚪ The results of XRF analyses showed that the CaO ratio increased after the carbon dioxide absorption.
⚪ The experimental results confirmed that the AABFS had high absorption capacity of carbon dioxide, suggesting that it can be used as a dry absorbent for carbon capture and sequestration and as a successful alternative of OPC.
⚪ In the formation of AABFS, the activator concentration affected the hydration reaction and changed the surface and internal structure, resulting in the changes of carbondioxide absorption capacity and rate.
(2) Construction Method of TiO₂ Concrete for Road Greenhouse Gas Removal
⚪ The first, attempt to locate TiO₂ to the surface of concrete, so we can use the concrete in pavement construction. The distribution of TiO₂ along the depth were confirmed by basing on the comparison of TiO₂ compare by using the EDAX(Energy Dispersive X-ray Spectroscopy). Nano size TiO₂ is easily penetration in the top 3mm of concrete surface. By the penetration TiO₂ concrete can be produced with the use of only 10% of TiO₂, by comparing the mixing types.
⚪ This study aimed to evaluate the NOx removal efficiency of photocatalytic concrete due to various TiO₂ application method such as mix with TiO₂, surface spray(TiO₂ penetration method) on hardened concrete and fresh concrete using surface penetration agents. The NOx removal efficiency of TiO₂ concrete was confirmed by NOx Analyzing System based on the specification of ISO 22197-1. The result, The NOx removal efficiency of mix with TiO₂ increased from 11 to 25 % with increasing of replacement ratio from 3 to 7 %. In case of surface spray on hardened concrete, the NOx removal efficiency was about 50 % due to application amount of TiO₂ with surface penetration agents as 300, 500 and 700 g/㎡. The NOx removal efficiency of surface spray on fresh concrete due to all experimental conditions, on the other hand, which was very low within 10%. It was known that the TiO₂ penetration method as surface spray on hardened concrete was a good alternative in order to remove the NOx gases for concrete road structures.
⚪ The environmental resistance test and the NOx removal efficiency was re-evaluated according to the respective properties of the specimen to conduct. Freezing and thawing resistance test and Surface scaling resistance test was conducted by, we re-evaluate the NOx removal efficiency of the sample was exposed to daylight about six months. NOx removal efficiency is evaluated on the basis of ISO 22197-1 As with the previous study it was confirmed by the analysis of nitrogen oxide system. The Result, It was found that the TiO₂ is reasonable applicable on the road structure because TiO₂ concrete has a long-term performance.
⚪ Evaluate the in-situ NOx removal efficiency of TiO₂ penetration method according to the field application. And to attain this end, TiO₂ penetration method was applied on the retaining wall of Jungbu expressway in Korea. The result of this study indicates that the NOx removal efficiency was changed from 11.1% to 21.2% by the difference of the sunlight quantity according to the weather condition. It was known that TiO₂ penetration method was feasible as an alternative in order to remove the NOx gases.