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Characteristics of Biochar based on its Carbonization Degree
RUZIEV JAMSHID,이지윤,이수정,김우석 한국복합신소재구조학회 2023 복합신소재구조학회논문집 Vol.14 No.6
Research is currently being conducted in the field of carbon reduction–related construction technologies, focusing on using industrial waste as a replacement for cement or as aggregates. However, the existing research is limited as carbon reduction is only achieved by reducing the amount of cement used. With the imperative of carbon neutrality, the development of carbon reduction technology is also necessary in the construction field. To address this, we plan to develop carbon reduction technology by introducing biochar—a carbon-sequestration material—into construction practices. Therefore, this study aims to comprehend the effect of the carbonization degree of biochar on the hydration reaction of cement, emphasizing the development of carbon-sequestration construction technology. Therefore, physical and chemical properties, such as surface and crystal structures, were analyzed to determine the effect of varying carbonization degrees on cement composites, contributing valuable insights into the broader field of sustainable construction.
포틀랜드 시멘트 복합체의 내구성 향상을 위한 세룰로오스 나노섬유 (CNF)의 활용
Ruziev Jamshid,김우석 한국복합신소재구조학회 2024 복합신소재구조학회 학술발표회 Vol.2024 No.04
The pursuit of sustainable and durable cementitious composites has led to a growing interest in alternative materials that can improve mechanical performance while reducing CO2 emissions. Nanomaterials, in particular, offer promising avenues due to their unique properties, including high surface area to volume ratio and increased reactivity. This study investigates the efficacy of Cellulose Nanofibers (CNF) in enhancing the durability of mortar exposed to sulfate attacks and alkali-silica reactions (ASR). Both MgSO4 and Na2SO4 solutions were employed to simulate sulfate attacks, while the role of CNF in mitigating ASR was also evaluated. Results indicate that CNF incorporation positively impacts the resistance of mortar against sulfate attacks and ASR, paving the way for eco-friendly and durable cement-based structures with extended service life.
Seed Germination Ecology of Giant Ragweed (Ambrosia trifida) in Korea
Farrukh Ruziev,In Kon Park,Mirjalol Umurzokov,Botir Khaitov,Aung Bo Bo,Wei Qiang Jia,Le Thi Hien,Jung Sup Choi,Kee Woong Park 한국잡초학회·한국잔디학회 2020 Weed & Turfgrass Science Vol.9 No.1
The effect of environmental factors on the growth of giant ragweed (ambrosia trifida) was determined in this study. Seed germination and seedling emergence were evaluated under different photoperiods, constant temperature, and periods after harvesting and burial depths. Dry storage of freshly harvested seeds caused slow release of dormancy at 25℃. The maximum germination rate of >65% was observed 11 months after harvest. Different light periods showed no significant impact to seed germination. The lowest germination was observed under complete darkness, while the highest germination was under alternating dark/light conditions. Regarding the temperature, giant ragweed seeds were able to germinate well at low temperatures (5-15℃) compared to high temperatures (30-40℃). The optimum temperature for germination was between 15 and 25℃ (>85%). Seedling emergence was initially increased up to 2 cm depth of burial, after which emergence declined sharply with increasing the burial depth up to 10 cm. There was no emergence beyond 10 cm depth of soil. The results indicated that giant ragweed seeds could germinate in cold months of spring regardless the light period. However, seeds need to overcome dormancy and be established superior levels of soil to have higher chance of propagation.
Jamshid Ruziev,김우석 한국콘크리트학회 2024 International Journal of Concrete Structures and M Vol.18 No.1
This study aims to investigate the effectiveness of para-aramid fiber sheet in enhancing the flexural performance of reinforced concrete (RC) beams made with Environmental-Friendly Recycled Coarse Aggregates. The experimental program examines the effect of substitution ratio of recycled aggregates (0%, 30%, and 50%), type of para-aramid fiber sheet (KN 206 RFL and KN AA070-RFL), and the method of fiber sheet attachment (bottom and bottom-side). The test results show that the ultimate load-carrying capacity of RC beams reinforced with para-aramid fiber sheet attached to the bottom and side parts increased by 23.9% compared to the unreinforced specimens. The main findings of the study include the identification of the BU-type attachment method as the most effective method for enhancing the flexural performance of reinforced concrete beams. The comparison of the experimental results with analytical predictions showed that the nominal flexural strength obtained from the experimental study was lower than the analytical predictions, but the ductile capacity of the specimens indicated the effectiveness of para-aramid fiber sheet reinforcement in EFRCA RC beams for flexural strength. The study highlights the potential of using para-aramid fiber sheet in improving the flexural behavior of RC beams made with recycled aggregates, offering a sustainable solution for the construction industry.
셀룰로오스 나노섬유 보강을 통한 시멘트 복합체의 내구성 및 지속가능성 강화: 실험 연구
김우석,Ruziev Jamshid,김상희 한국복합신소재구조학회 2024 복합신소재구조학회 학술발표회 Vol.2024 No.04
The significance of this study lies in addressing critical issues prevalent in the worldwide construction sector, particularly concerning the durability and sustainability of cement-based materials. Plain cement composites commonly suffer from deficiencies in tensile strength and strain capacity, resulting in the formation of nano-cracks under relatively low tensile loads. These nano- cracks pose a significant challenge to the longevity and resilience of cement matrices, contributing to structural degradation and reduced service life of infrastructure. To mitigate these challenges, the integration of cellulose nanofibers (CNF) as reinforcements in cement composites presents a promising solution. CNF, renowned for their exceptional material properties including high stiffness, tensile strength, and corrosion resistance, offer the potential to significantly enhance the mechanical performance and durability of cement-based materials. Through systematic experimentation, this study investigates the effects of CNF reinforcement on the mechanical properties of cement composites. By leveraging ultrasonically dispersion techniques, CNF extracted from bamboo, broad leaf, and kenaf are uniformly dispersed within the cement matrix at varying concentrations. Compressive and flexural tests are subsequently conducted to evaluate the impact of CNF on the strength characteristics of the cement composites. By elucidating the efficacy of CNF reinforcement through rigorous experimentation, this study aims to provide valuable insights into the development of construction materials with improved durability and sustainability. Ultimately, this research contributes to addressing critical challenges in the construction industry, offering potential solutions to enhance the performance and longevity of cement-based infrastructure.