Alexandria Engineering Journal
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2024
·
IF 6.2
Hong Zhang,Ming Chen,Tiantian Liang,Zanpeng Zhang,Changhui Yang
The use of nanocarbon materials to enhance the toughness of fragile cementitious materials has attracted increasing attention for investigation. This study examines the effects of incorporating graphene oxide (GO) into NaOH-activated slag (AAS) pastes and mortars, focusing on workability, phase composition, mechanical properties, and the local mechanical properties of the interfacial transition zone (ITZ) between sand and paste. The experimental results indicate that the addition of GO decreases the flowability of NaOH-AAS pastes, with noticeable aggregation at concentrations above 0.03 wt%. Furthermore, GO enhances the hydration degree of ground granulated blast furnace slag (GGBS), leading to an increased amount of C-A-S-H gel without introducing new phases. In terms of macro performance, incorporating 0.03 wt% GO significantly improves the compressive and flexural strengths of NaOH-AAS mortars by 10.6 % and 17.9 %, respectively. Additionally, the presence of GO reduces the ITZ thickness from 30 to 15 micrometres in NaOH-AAS mortars, which likely contributes to the enhanced mechanical performance.
研究领域:
材料科学
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水泥基材料
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纳米复合材料
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建筑材料化学
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界面工程
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 16
·47025-47037
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IF 5.8
Wang Tianyu,Yang Lang,Rao Feng,Jiang Kaixi,Byrynnai Choduraa
Adding organics in the process of geopolymer synthesis can combine the functional groups of organics with the three-dimensional structure of geopolymer, thus changing the properties of geopolymer such as compressive strength, flexural strength, and acid resistance. In this work, excellent mechanical properties and acid resistance of metakaolin-blast furnance slag (Mk-BFS)-based geopolymer were synthesized by the incorporation of chitosan. The formation of sodium-alumino-silicate-hydrate (N-A-S–H) gel and calium-alumino-silicate-hydrate (C-A-S–H) gel in geopolymerization were characterized by 29 Si nuclear magnetic resonance (NMR). At 5% of chitosan, the compressive strength of Mk-BFS-based geopolymer could reach to 33.7 MPa. The results could be ascribed to that chitosan reacts with geopolymer to generate new C-O-Si structure meanwhile adhesion produced by the combination of positively charged cations and negatively charged ions makes the structure of geopolymer denser. After 7 days of sulfuric acid immersion, the reduction of compressive strength is less than 3 MPa, demonstrating its great acid resistance. The acid resistance of Mk-BFS-based geopolymer could attribute to that the free amino groups in chitosan preferentially react with acid solution and weakened the erosion of sulfuric acid. This study optimizes the compressive strength and acid resistance of geopolymer by adding appropriate amount of chitosan.
研究领域:
材料科学
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硅酸盐化学
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无机非金属材料
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功能复合材料
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建筑材料
✓ 已验证
DOI
高影响因子
Journal of Building Engineering
·
2025
·
IF 7.4
Juanhong Liu,Yayun Xi,Fanghui Han,Lingzhi Guo,Jinmei Hu
This study investigates the influence of aluminum incorporation on the chemical composition, morphology, silicate chain structure, and functional groups of C(-A)-S-H gel through micro- and nanoscale characterization. Based on experimental data, an atomic-scale structural model was constructed to closely reflect realistic Ca/Si and Al/Si ratios as well as Q n distributions, and to explore the effects of aluminum content on the mechanical properties and failure mechanisms of C-A-S-H at the atomic level. Results show that at low Al/Si ratios, Al can be effectively incorporated into the C-S-H gel; however, when Al/Si exceeds 0.10, Al-containing secondary phases start to precipitate. Al atoms bridge defects in silicate chains, extend the length of aluminosilicate chains, and form crosslinking structures along the z direction, with the degree of crosslinking increasing with Al content. Simulation results further indicate that Al incorporation restricts the diffusion pathways of interlayer water molecules, thereby enhancing gel structural integrity. Meanwhile, the formation of a three-dimensional crosslinking network substantially improves mechanical performance, significantly increasing Young's modulus and tensile strength in the y and z directions—especially enhancing interlayer cohesion and ductility along the z direction . Under tensile loading, stress-induced hydrolysis and bond depolymerization accelerate bond cleavage and hydroxyl formation within the C-A-S-H.
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产品关联
DOI
高影响因子
CEMENT & CONCRETE COMPOSITES
·
2022
·
IF 9.93
Xing Ming,Qing Liu,Miaomiao Wang,Yongqing Cai,Binmeng Chen,Zongjin Li
Chloride-induced corrosion in reinforced concrete is a primary durability issue that causes large economic loss every year. To improve the intrinsic chloride binding capacity and realize a favorable corrosion protection of cement-based materials are thus crucial to prolong the service life of concrete structures. Here, alumina nano particles (ANPs) were incorporated to improve the chloride binding capacity of cement pastes in chloride solutions and the anti-corrosion performance of mortars under accelerated corrosion process. The ANPs facilitated the formation of alumino-ferrite-mono (AFm)-type phases, thereby improved the content of chemically bound chlorides. Solution calcium (Ca) ions benefited the chloride captured by calcium-(alumino-)silicate-hydrates (C-(A-)S-H) in the assistance of ANPs, especially at high initial chloride concentrations , and further evoked a pH-related chloride binding response. Moreover, the enhanced corrosion resistance was finally realized by incorporating appropriate amount of ANPs because of the filling and chemical effects induced low permeability of mortars. In general, the ANPs possess dual functions in the aspects of chloride binding and corrosion inhibition . These findings are expected to advance the design of high-durable cement-based materials serviced in the marine environment.
研究领域:
建筑材料
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土木工程材料
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腐蚀科学
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纳米材料应用
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混凝土耐久性
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）