바이오매스에서 얻어지는 바이오차는 토질 개량제와 탄소 격리제로 제한적인 분야에서 성공적으로 사용되고 있다. 현재 산업전반에서 CO2 에 의한 환경에 부정적인 영향을 완화시키고 지속가능성을 증진시키기 위한 연구가 활발히 진행되고 있다. 이에 본 연구에서는 고탄소 바이오차를 탄소 격리제 또는 시멘트의 혼화재로써 활용 가능성을 평가하고자 하였다. 견목재에서 얻어진 바이오차를 혼화재로 사용하여 시멘트 배합조건을 달리하면서 모타르의 압축강도, 마이크로구조, 압축강도, 유동성, 중량감소와 같은 화학적, 물리적 재료성질을 평가하였다. 또한 플리이애쉬를 사용한 모르타르의 역학적 특성과 비교 평가하였다.
바이오매스에서 얻어지는 바이오차는 토질 개량제와 탄소 격리제로 제한적인 분야에서 성공적으로 사용되고 있다. 현재 산업전반에서 CO2 에 의한 환경에 부정적인 영향을 완화시키고 지속가능성을 증진시키기 위한 연구가 활발히 진행되고 있다. 이에 본 연구에서는 고탄소 바이오차를 탄소 격리제 또는 시멘트의 혼화재로써 활용 가능성을 평가하고자 하였다. 견목재에서 얻어진 바이오차를 혼화재로 사용하여 시멘트 배합조건을 달리하면서 모타르의 압축강도, 마이크로구조, 압축강도, 유동성, 중량감소와 같은 화학적, 물리적 재료성질을 평가하였다. 또한 플리이애쉬를 사용한 모르타르의 역학적 특성과 비교 평가하였다.
Bio-char, obtained from biomass as a by-product of the pyrolysis process, is used successfully as a soil amendment and carbon sequester in this limited study. Recent and active research from literatures has extended the application of bio-char in the industry to promote sustainability and help mitig...
Bio-char, obtained from biomass as a by-product of the pyrolysis process, is used successfully as a soil amendment and carbon sequester in this limited study. Recent and active research from literatures has extended the application of bio-char in the industry to promote sustainability and help mitigate the negative environmental impacts caused by carbon emissions. This study aims to investigate the feasibility of high-carbon bio-char as a carbon sequester and/or admixture in mortar and concrete to improve the sustainability of concrete. This paper presents the experimental results of an initial attempt to develop a cement admixture using bio-char. In particular, the effects of the water retention capacity of bio-char in concrete are investigated. The chemical and mechanical properties (e.g., the chemical components, microstructure, concrete weight loss, compressive strength and mortar flow) are examined using sample mortar mixes with varying replacement rates of cement that contains hardwood bio-char. The experimental results also are compared with mortar mixes that contain fly ash as the cement substitute.
Bio-char, obtained from biomass as a by-product of the pyrolysis process, is used successfully as a soil amendment and carbon sequester in this limited study. Recent and active research from literatures has extended the application of bio-char in the industry to promote sustainability and help mitigate the negative environmental impacts caused by carbon emissions. This study aims to investigate the feasibility of high-carbon bio-char as a carbon sequester and/or admixture in mortar and concrete to improve the sustainability of concrete. This paper presents the experimental results of an initial attempt to develop a cement admixture using bio-char. In particular, the effects of the water retention capacity of bio-char in concrete are investigated. The chemical and mechanical properties (e.g., the chemical components, microstructure, concrete weight loss, compressive strength and mortar flow) are examined using sample mortar mixes with varying replacement rates of cement that contains hardwood bio-char. The experimental results also are compared with mortar mixes that contain fly ash as the cement substitute.
* AI 자동 식별 결과로 적합하지 않은 문장이 있을 수 있으니, 이용에 유의하시기 바랍니다.
가설 설정
The overall research objective in this study is to provide quantitative information about bio-char so that it can be used as a carbon sequestration agent in concrete and/or as a self-curing agent. First, it is hypothesized that the high carbon content of bio-char can be captured in concrete without substantial negative side effects, such as reduction in compressive strength and durability. Second, it is hypothesized that the high water retention capacity of carbon in bio-char can help to reduce the evaporation of water in concrete and provide water for the hydration process.
제안 방법
, moisture-cured or air-cured. A total of 11 mortar mixes were considered for the compressive strength testing, and selected mortar mixes from these 11 mixes were used for the flow test and weight loss test. Detailed mortar mix information for each test is shown in Table 3.
After 24 hours, the specimens were demolded and then moisture-cured for 28 days followed by air curing at room temperature. All specimens were air-dried for 24 hours prior to the compressive strength testing at 14 days and 28 days. For the air-cured specimens, all of the specimens were demolded after 24 hours and air-cured at room temperature.
Finally, to measure the compressive strength in the specimens during the hydration process, the cube samples were tested at 14 days, 28 days, and 56 days after casting. After 24 hours, the specimens were demolded and then moisture-cured for 28 days followed by air curing at room temperature.
Hardwood char obtained from slow pyrolysis, which is commercially available, was prepared in this study to examine the water retention effects of mortar mix samples. As mentioned earlier, the chemical components of hardwood char show a high content of carbon along with a few acidic oxides.
In this study, the chemical and material properties (e.g., chemical components, microstructures, concrete weight loss, compressive strength and mortar flow) of bio-char are examined using sample mortar mixes that have varied replacement rates of bio-char. Two different curing methods, air-cured and moisture- cured, are used for the compressive strength testing.
During the test, the mortar will spread (or flow) to form a circular mass, and the diameter of the mass is measured and compared to the initial size. In this study, the flow test was conducted twice for each mortar mix, and the average values were computed.
Although the different mixes had different water to cement ratios, they were made in the same manner. Once all the mixes were made, the initial weights were recorded immediately after mixing, after which the weights were recorded in the following intervals: 1 hour, 3 hours, 6 hours, 1 day, 2 days, 3 days, 7 days, 10 days, 15 days, 20 days, and 28 days. Thus, the weights were recorded and the charts were created using the amount of water that had evaporated from the concrete.
The overall research objective in this study is to provide quantitative information about bio-char so that it can be used as a carbon sequestration agent in concrete and/or as a self-curing agent. First, it is hypothesized that the high carbon content of bio-char can be captured in concrete without substantial negative side effects, such as reduction in compressive strength and durability.
This test was designed to determine the water content needed for a cement paste sample. The test utilizes a specially designed table that repeatedly raises and drops a known quantity of mortar 25 times.
대상 데이터
The main variables in this study are mortar mixes that contain different amounts of bio-char replacement. For this research, a mixture of cement (typical Portland cement) and fine aggregate (i.e., sand) was cast in 2 in. (50 mm) by 2 in (50 mm).
성능/효과
(3) The results for both the percentage of flow and compressive strength tests indicate that a certain amount of bio-char could be added to concrete mixtures as a carbon sequester and/or cement substitute up to a 5% replacement rate without a significant reduction in compressive concrete strength and a comparable percentage of flow. Bio-char replacement has the potential to help internal curing in concrete mixtures due to improved hydration over time under drying conditions compared to conventional concrete.
Limited results from these experiments indicate that 5% to 10% replacement with bio-char is comparable to 20% replacement with fly ash. However, the appropriate amount of bio-char that is needed to obtain the desired workability might vary depending on the LOI level in the bio-char.
2% percent. The results found in the literature indicate that the fly ash has a LOI above 3%. It is likely the water requirements are higher.
참고문헌 (15)
American Society for Testing and Materials (ASTM), ASTM C 618:Standard specification for coal fly ash and raw or calcined natural pozzolan for use as a mineral admixture in concrete. In Annual Book of ASTM Standards 04.02, 2001.
ASTM C1437, Standard Test Method for Flow of Hydraulic Cement Mortar. Philadelphia, PA, 2001.
Brewer, C. E., K. Schmidt-Rohr, J. A. Satrio and R. C. Brown., Characterization of biochar from fast pyrolysis and gasification systems. Environmental Progress & Sustainable Energy vol. 28, No. 3, 2009, pp.386-396.
Brummer, E. C., C. L. Burras, M. D. Duffy and K. L. Moore, Switchgrass Production in Iowa: Economic Analysis, Soil Suitability, and Varietal Performance. Final Report for Bioenergy Feedstock Development Program. Iowa State University, 2001.
Canadian biochar initiative, http://www.biochar.ca/
Chusilp, N., C. Jaturapitakkul and K. Kiattikomol, Effect of LOI of ground bagasse ash on the compressive strength and sulfate resistance of mortars, Construction and Building Materials vol. 23, No. 12, 2009, pp.3,523-3,531.
Cordeiro, G. C., R. D. T. Filho and E. M. R. Fairbairn, Use of ultrafine rice husk ash with high-carbon content as pozzolan in high performance concrete, Materials and Structures, vol. 42, No. 7, 2009, pp.983-992.
Dhir, P. K., P. C. Hewlett and T. D. Dyer, Mechanism of water retention in cement pastes containing a self-curing agent, Magazine of Concrete Research vol. 50, No. 1, 1998, pp.85-90.
Sohi, S., E. Loez-Capel, E. Krull and R. Bol, Biochar's roles in soil and climate change: A review of research needs, CSIRO Land and Water Science Report 05/09, 2009, p.64.
Wang, J., R. K. Dhir and M. Levitt, Membrane curing of concrete, Cement Concrete Research vol. 24, No. 8, 1994, pp.1,463-1,474.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.