CONSTRUCTION AND BUILDING MATERIALS
·
2023
·
IF 7.4
Yanchen Oinam,Suhawn Ju,Myoungsu Shin,Sukhoon Pyo
This study aimed to investigate the influence of natural cellulose fibers (NCFs) on improving the hydration characteristics of cementless ultra-high performance concrete (UHPC) using CaO-activated ground granulated blast furnace slag (GGBFS). The NCFs were added in a saturated condition as an internal-curing agent so as to supply additional water to the UHPC matrix and subsequently increase the reactivity of unhydrated phases. To evaluate the hydration characteristics, saturated NCFs were added at 0 to 1.5 wt% of the GGBFS plus CaO. TGA and FTIR analyses showed that, as the amount of NCFs increased, the formation of hydration products was improved as evidenced by an increase in heat of hydration, indicating that more reactions of unhydrated phases occurred. Similarly, morphologies of the samples revealed the formation of hydration products on and near the surfaces of the NCFs due to the additional water exerted during the process of internal curing. Moreover, the compressive and tensile strengths were not compromised by the incorporation of weak and flexible NCFs, but rather a slight improvement was observed with a certain content of NCFs.
研究领域:
土木工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Building Engineering
·
2023
·
IF 6.4
Mandip Dahal,Yanchen Oinam,Prabhat Vashistha,Jae-Eun Oh,Sukhoon Pyo
This study proposes an innovative approach to develop cementless ultra-high performance concrete (UHPC) by activating ground granulated blast furnace slag (GGBFS) without an alkaline-activating solution. To develop cementless UHPC, calcium oxide (CaO) (5% by weight) was used to activate GGBFS, and calcium formate (CF) was used as an accelerator at concentrations ranging from 0 to 6 wt%. The results showed that CF significantly improved the mechanical properties until 5 wt% and all the samples, including CF, exhibited a compressive strength of over 150 MPa. Uniaxial tensile tests revealed strain-hardening behavior, similar to typical cement-based UHPC. The addition of CF led to an increase in hydration products and pore size refinement, resulting in improved mechanical properties. The life cycle assessment results indicated that the developed UHPC mixture had nearly 70% lower CO 2 emission than cement-based UHPC. The experimental results highlight the potential of this method for sustainable UHPC development.
研究领域:
土木工程
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CEMENT & CONCRETE COMPOSITES
·
2023
·
IF 10.5
Zhongtao Luo,Tianyi Zhi,Xiaohai Liu,Kunpeng Yin,Han Pan,Hu Feng,Yatao Song,Yanfeng Su
The early hydration of UHPC can be retarded by the low water/binder ratio, the high polycarboxylate superplasticizers dosage, and the large supplementary cementitious materials (SCM) content. In this study, the effects of the prepared nanoscale C–S–H seeds and nano-silica (NS) on the early performance of UHPC were compared. The mechanism of nanomaterials influencing the early hydration of UHPC was further characterized by calorimetry , thermal analysis, nuclear magnetic resonance (NMR), and mercury intrusion porosimetry . The results showed that the 1-day compressive strength of UHPC samples with 0.3 wt% C–S–H seeds and NS increased by 457% and 25% respectively compared to the control sample. Compared to NS, C–S–H seeds were more effective in accelerating the early (before 3 d) hydration to produce hydrates and refine the pore structure of UHPC. The NMR results further implied that compared with the NS, the C–S–H seeds was 12% and 343% more efficient in accelerating the early hydration of cement and SCMs, respectively. However, the performance enhancement of nanomaterials was effective at 1 d and had little effect thereafter.
研究领域:
土木工程
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材料科学
✓ 已验证
DOI
高影响因子
Developments in the Built Environment
·
2023
·
IF 8.2
Yanchen Oinam,Prabhat Vashishtha,Mandip Dahal,Sukhoon Pyo
This study investigates the potential use of calcined lime mud as an activator in the development of a sustainable, ground granulated blast furnace slag (GGBFS)-based cementless UHPC. The effects of the calcination temperature (550 °C to 850 °C) of lime mud and its weight percentage in the UHPC mixture were evaluated with various tests, such as compressive strength, isothermal calorimeter, and thermogravimetric analysis. Microstructural changes and pore size distribution were also analyzed using XRD, FTIR, and MIP. The results showed that calcined lime mud can be an effective activator in the UHPC mix, and its mechanical properties are influenced by the calcination temperature and weight percentage. The addition of 10% calcined lime mud enhanced the compressive strength of the UHPC up to 150 MPa without negatively affecting its microstructural and hydration characteristics, suggesting that calcined lime mud has the potential to be used as a sustainable alternative to CaO in GGBFS-based cementless UHPC.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Building Engineering
·
2024
·
IF 6.7
Yanchen Oinam,Mandip Dahal,Minwuye Mesfin,Solmoi Park,Hyeong-Ki Kim,Sukhoon Pyo
The study aimed to achieve high strength in slag-based cementless ultra-high performance concrete (UHPC) while investigating the role of calcium formate and calcium chloride as accelerators using advanced characterization and microstructural analysis . The UHPC specimens were evaluated using various techniques, including heat of hydration, thermogravimetric analysis , X-ray diffraction, nuclear magnetic resonance, scanning electron microscopy, and porosity measurements . The results showed that both accelerators improved the UHPC properties, with calcium formate being more effective than calcium chloride, as evidenced by higher heat of hydration, improved microstructure, and lower porosity. Furthermore, the thermodynamic modeling revealed insightful information on the reaction mechanisms with C-(N-)A-S-H and hydrotalcite as the primary hydration products formed in the matrix. Notably, the UHPC specimens with calcium chloride exhibited a very low pH value, which could increase the risk of corrosion in reinforced structures. Therefore, the use of calcium formate as an accelerator can lead to the development of cementless UHPC with superior properties.
研究领域:
材料科学
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土木工程
✓ 已验证
产品关联
DOI
高影响因子
Developments in the Built Environment
·
2026
·
IF 8.7
Yanchen Oinam,Aidarus Yonis,Kebede Alemayehu Moges,Sukhoon Pyo
Ultra-high performance concrete (UHPC) is increasingly recognized for its exceptional strength and durability, but its reliance on silica fume raises concerns regarding availability and sustainability. In this study, metakaolin (MK) and thermally treated waste concrete powder (WCP) were independently investigated as partial substitutes for silica fume in a CaO-activated ground granulated blast furnace slag (GGBFS) based cementless UHPC system. Steam curing at 90 °C accelerated hydration, promoting the formation of stable hydrates such as C-A-S-H, hydrotalcite, and wollastonite, and resulting in compressive strengths exceeding 160 MPa. In contrast, normal curing led to slower hydration, characterized by residual portlandite and ettringite alongside sharper C-A-S-H decomposition, producing compressive strengths below 100 MPa. Low levels of WCP replacement provided beneficial filler effects and improved performance, whereas higher replacement levels of both MK and WCP caused strength reductions. Life cycle assessment demonstrated substantial reductions in CO 2 emissions and mineral resource consumption compared with cement-based UHPC.
✓ 已验证
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Yanchen Oinam,Kebede Alemayehu Moges,Prabhat Vashistha,Sukhoon Pyo
This study investigates the impact of incorporating lime mud (LM) as a filler material to develop sustainable, cementless ultra-high performance concrete (UHPC) by replacing silica powder (SP) and silica sand (SS) at varying percentages. Flowability analysis reveals that LM, with its distinctive particle size, influences flow characteristics differently at different replacement levels. Compressive strength was improved by 5.4% with 30% SP replacement, showcasing the role of LM in nucleation, as well as its particle size advantage. The heat of hydration analysis indicates that LM likely influences the early curing stages, enhancing reactivity and nucleation. TGA analysis also confirms that LM plays a role in hydration reaction , influencing weight loss and hydration peaks. The mercury intrusion porosimeter results show the impact of LM on pore distribution, with 30% for SP and 50% for SS replacements, favoring denser matrices. Life cycle assessment (LCA) demonstrates reduced CO 2 emissions and favorable environmental performance, highlighting the sustainability potential of LM replacements. Overall, the incorporation of LM in UHPC shows promise in terms of enhancing its mechanical properties and environmental sustainability.
研究领域:
土木工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Developments in the Built Environment
·
2025
·
IF 8.2
Min-Chang Kang,Munhwa Kang,Goeun Jun,Yanchen Oinam,Hong Min Seung,Sukhoon Pyo
This study presents a sustainable and intelligent alternative to conventional cement-based ultra-high performance concrete (UHPC) by developing a CaO-activated GGBFS cementless UHPC incorporating rapid-cooled electric arc furnace oxidizing slag (REOS) as a replacement for natural aggregates. As an industrial byproduct, REOS enhances mechanical performance while promoting electrical conductivity, forming efficient conductive networks within the matrix. These pathways enable self-sensing capabilities, allowing the material to detect stress and strain without external sensors. The experimental results showed that REOS improved fluidity (up to 235 mm) and maintained high compressive strength (exceeding 200 MPa). Additionally, it was found that REOS enhanced tensile properties, achieving tensile strength exceeding 21 MPa and maximum strain capacity of 0.72 %, particularly when combined with 0.3 % carbon fiber. The incorporation of carbon fiber significantly reduced electrical resistivity compared to the composite without carbon fiber. Furthermore, a life cycle assessment (LCA) demonstrated the environmental benefits of REOS, showing approximately 53 % lower carbon dioxide (CO 2 ) emissions per unit compressive strength compared to traditional UHPC. This research highlights the multifunctionality of REOS in improving both performance and sustainability, offering valuable insights into the development of next-generation UHPC that integrates advanced sensing capabilities and aligns with circular economy principles.
研究领域:
土木工程
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材料科学
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可持续建筑材料
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智能材料
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结构工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
·
2023
·Vol. 35
·期 10
·04023328
·
IF 3.2
Qingjun Ding,Yongyuan Zhang,Gaozhan Zhang,Yang Li,Jinhua Gong,Changsheng Zhou,Hao Qian
The application of waste tire rubber in the concrete industry is one of the most effective and environmentally friendly ways to solve the problem of so-called black pollution. However, the application of rubber particles (RP) in the concrete industry is hindered by their low stiffness and poor bonding performance with the cement matrix. In this paper, a novel modification method of polydopamine (PDA) modification was used to enhance the hydrophilicity of the RP surface. The surface morphology, element content, and hydrophilicity of RP treated with PDA and KMnO4 were analyzed through scanning electron microscope and energy dispersive spectrometer (SEM-EDS) and sedimentation methods. The unit weight, ultrasonic pulse velocity (UPV), compressive strength, compressive toughness, toughness index, and flexural strength were taken to determine the mechanical properties of ultrahigh-performance rubber concrete (RUHPC). The results showed that the adhesion between paste and RP and the sedimentation rate of RP with PDA or KMnO4 treatment methods exhibited a remarkable improvement. Compared with unmodified RUHPC, the basic mechanical properties of KMnO4-modified RUHPC were improved slightly, and its toughness index was improved greatly. SEM and EDS results confirmed that PDA was deposited on the surface of RP, eliminating the gap of interface transition zone and significantly enhancing UPV, compressive strength, and flexural strength of RUHPC by 4.1%–5.8%, 17%–20%, and 6.1%–9.8%, respectively. In addition, the compressive toughness of unmodified and KMnO4-modified RUHPC decreased, whereas that of PDA-modified RUHPC increased significantly. It can be concluded that the mechanical properties of RUHPC with treated RP have improved significantly and the application of RP in ultrahigh-performance composites (UHPC) offers more opportunities for recycling RP.
研究领域:
土木工程
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建筑材料
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可持续发展
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聚合物改性
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混凝土技术
✓ 已验证
DOI
高影响因子
Case Studies in Construction Materials
·
2024
·
IF 6.5
Mohammed M. Attia,Mahmoud Malek Olwan,Essam Amoush,Shady Rizk Ragheb Hassan Aamer,M.A. Eita
This study evaluated the uniaxial tensile strength and bond performance of natural hybrid reinforcement bars. Hybrid FRP combines multiple fibers and matrixes, resulting in a desirable performance. Two types of hybrid bars were tested: one with natural fibers surrounded by glass fiber, and the other with a steel core surrounded by natural fiber and then glass fiber. Thirteen samples were used to assess tensile behavior, with four groups including glass fiber, flax, sisal, and jute fibers. Pull-out behavior testing was conducted on twelve samples, divided into four groups of fiberglass, flax, sisal, and jute. Each group used three types of concrete: normal, high strength, and ultra-high-performance concrete (UHPC). The results refer to flax samples that had a higher tensile strength and elastic modulus of 143 MPa and 38 GPa, respectively, than samples made of sisal and jute fibres. The hybrid bars with a steel core exhibited a significant improvement in elastic modulus of 206 % in compared to samples made solely from glass, sisal, and jute fibers. On the other hand, the samples with UHPC showed the highest bond strength. The sample U-GFRP with ultra-high-performance concrete showed the highest bond strength 9.32 MPa, while the sample N-GFRP with normal concrete showed the lowest bond strength 5.87 MPa, respectively. However, this study suggests that hybridizing natural fibers can be a cost-effective and eco-friendly alternative to synthetic fibers.
研究领域:
土木工程
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材料科学
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环境科学
✓ 已验证
DOI
高影响因子
Coatings
·
2024
·Vol. 14
·期 12
·1482
·
IF 2.9
Tusheng He,Wei Xie,Feng Wang,Zi Yu,Fang Xu,Jinhui Li,Yitong Deng,Qingjun Ding,Yan Hao,Wei Xu,Haibin Yu
To further enhance the abrasion resistance of UHPC in demanding abrasion environments, this study investigated the effects of graphene oxide (GO) on the workability, mechanical properties, and abrasion resistance of UHPC. Utilizing 27Al Nuclear Magnetic Resonance (NMR), 29Si NMR, microhardness, and BET analysis, the study analyzed the mechanisms through which GO influences UHPC’s microstructure in terms of abrasion resistance. Additionally, molecular dynamics simulations were employed to examine the mechanisms by which GO enhances UHPC’s abrasion resistance at the nano and micron scale. The findings show that an optimal amount of GO can improve the mechanical properties and abrasion resistance of UHPC. When 0.03% of GO (by cementitious material mass) was incorporated, the impact on workability was minimal, yet compressive strength increased by approximately 1.80%, flexural strength by 3.02%, impact wear resistance by 1.78%, the abrasion loss rate decreased by 10.01%, ultimate impact energy increased by 1.76%, and the toughness index improved by 10.10%. GO enhances abrasion-resistant UHPC primarily by increasing hydration, refining pore structure, and improving the microstructure of the interfacial transition zone. While GO increases the hydration degree of the UHPC matrix, it does not alter the silicate chain in C-A-S-H gels within the paste. Additionally, the incorporation of graphene oxide can refine the pore structure of the UHPC cement paste and improve the microstructure of the interfacial transition zone (ITZ) between the aggregate and the cement paste. The molecular dynamics simulation reveals that, under abrasive forces, GO forms strong, stable chemical bonds with the C-A-S-H base atoms, significantly enhancing the abrasion resistance of C-A-S-H.
研究领域:
建筑材料
·
土木工程材料
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纳米复合材料
·
混凝土耐久性
·
微观结构表征
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）