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学者姓名：王德辉
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Abstract ：
混凝土的碱硅酸反应(Alkali-silica reaction, ASR)本质上是孔溶液中的离子、水分子与骨料中活性二氧化硅的反应。根据不同离子对ASR的影响效果，可将离子分为碱离子(Na~+、K~+和OH~-)、锂离子和铝离子、钙离子。碱离子(Na~+、K~+和OH~-)促进混凝土的碱硅酸反应，导致混凝土发生更严重的膨胀性破坏。Al~(3+)和Li~+减缓混凝土碱硅酸反应造成的膨胀性破坏；Ca~(2+)起到的作用与n(Ca)/n(Si)(物质的量比)密切相关，当n(Ca)/n(Si)<0.2时，Ca~(2+)对ASR起促进作用；当n(Ca)/n(Si)≥0.2时，Ca~(2+)对ASR起抑制作用。本文首先介绍了ASR反应产物的最新研究进展，包括ASR产物的种类、微观形貌、原子结构及水稳定性，综述了这些离子对ASR反应过程、ASR产物组成、ASR产物结晶性能及膨胀性的影响，展望了不同离子对混凝土ASR影响的未来研究方向。
Keyword ：
ASR产物 ASR产物 碱硅酸反应 碱硅酸反应 碱离子 碱离子 钙离子 钙离子 铝离子 铝离子 锂离子 锂离子
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| GB/T 7714 | 龚青南 , 王德辉 . 不同离子对混凝土碱硅酸反应影响的研究进展 [J]. | 材料导报 , 2024 , 38 (02) : 89-103 . |
| MLA | 龚青南 等. "不同离子对混凝土碱硅酸反应影响的研究进展" . | 材料导报 38 . 02 (2024) : 89-103 . |
| APA | 龚青南 , 王德辉 . 不同离子对混凝土碱硅酸反应影响的研究进展 . | 材料导报 , 2024 , 38 (02) , 89-103 . |
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Seawater sea sand concrete (SWSSC) is considered a potential solution to the shortage of river sand and freshwater resources in the coastal and island regions. Under the marine environment, the sulfate ions in the seawater and sea sand are detrimental to the properties of concrete. Due to the lack of systematic research on the sulfate attack characteristics of SWSSC exposed to different marine conditions, this study compare the sulfate resistance between SWSSC and freshwater desalinated sea sand concrete (FDC) under full immersion, semi -immersion, and dry -wet cycle exposure through the compressive strength, sulfate ion distribution, and microstructural changes after erosion. The findings showed that among the three different exposure conditions, the damage in SWSSC-F (fully immersion) was more severe than that in SWSSC-S (semi -immersion) and SWSSC-DW (dry -wet cycle). The SO42- concentration in inner SWSSC-F was 9.3% and 21.3% higher than that in SWSSC-DW and SWSSC-S, respectively. The microstructural analysis indicated that the higher amount of sulfate attack products and the leaching of Ca2+/OH- in SWSSC-F significantly damaged its microstructure. Besides, carbonation and physical crystallization in SWSSC-S and SWSSC-DW also refined their pore structure, thus enhancing their sulfate resistance. SWSSC showed better sulfate resistance than FDC under different marine exposure conditions in terms of lower erosion product content and better pore structure distribution after 12 months of erosion. The formation of Friedel's salt in SWSSC suppressed the formation of expansion products and reduced the erosion damage of concrete by SO42-.
Keyword ：
Dry -wet cycle Dry -wet cycle Freshwater and desalinated sea sand concrete Freshwater and desalinated sea sand concrete Full immersion Full immersion Seawater sea sand concrete Seawater sea sand concrete Semi -immersion Semi -immersion Sulfate attack Sulfate attack
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| GB/T 7714 | Zhang, Dong , Jiang, Jianwei , Zhang, Zhiwen et al. Comparative analysis of sulfate resistance between seawater sea sand concrete and freshwater desalted sea sand concrete under different exposure environments [J]. | CONSTRUCTION AND BUILDING MATERIALS , 2024 , 416 . |
| MLA | Zhang, Dong et al. "Comparative analysis of sulfate resistance between seawater sea sand concrete and freshwater desalted sea sand concrete under different exposure environments" . | CONSTRUCTION AND BUILDING MATERIALS 416 (2024) . |
| APA | Zhang, Dong , Jiang, Jianwei , Zhang, Zhiwen , Fang, Lei , Weng, Yiwei , Chen, Longhui et al. Comparative analysis of sulfate resistance between seawater sea sand concrete and freshwater desalted sea sand concrete under different exposure environments . | CONSTRUCTION AND BUILDING MATERIALS , 2024 , 416 . |
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The application of seawater and sea sand concrete (SWSSC) is beneficial for marine engineering, but the impact of aggregate gradation on its alkali-silica reaction (ASR) remains poorly understood. This study aims to bridge this gap by analyzing ASR products, pore characteristics and expansion rate of specimens. The test results reveal that ordinary concrete (OC) exhibits an inhibitory effect on ASR in comparison with to SWSSC. The 14-day expansion of ordinary concrete and SWSSC with the same aggregate gradation are 0.130 % and 0.212 %, showing potential and high risk of ASR, respectively. Moreover, particle size and gradation of aggregate are the key factors influencing the ASR degree of SWSSC. Compared with coarser aggregate, specimens with finer aggregate consume more K+ and Ca2+ ions, generate more ASR-P1, form less porosity, and produce a larger expansion. Additionally, specimens with gap-graded aggregates, as opposed to those with uniform or continuous gradation, show greater consumption of K+ and Ca2+ ions, increased ASR-P1 formation, more harmful pore formation, and a larger expansion. These results offer insights into optimizing aggregate gradation to reduce ASR in SWSSC and improve its durability. © 2024
Keyword ：
Concrete aggregates Concrete aggregates Expansion Expansion Particle size Particle size Seawater corrosion Seawater corrosion Silica Silica
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| GB/T 7714 | Wu, Wenda , Kang, Sixiang , Gong, Qingnan et al. Influences of aggregate gradation on alkali-silica reaction of seawater and sea sand concrete [J]. | Construction and Building Materials , 2024 , 427 . |
| MLA | Wu, Wenda et al. "Influences of aggregate gradation on alkali-silica reaction of seawater and sea sand concrete" . | Construction and Building Materials 427 (2024) . |
| APA | Wu, Wenda , Kang, Sixiang , Gong, Qingnan , Yao, Hongyu , Zhang, Kaijian , Yang, Hongfei et al. Influences of aggregate gradation on alkali-silica reaction of seawater and sea sand concrete . | Construction and Building Materials , 2024 , 427 . |
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Economic and environmentally friendly polypropylene (PP) fibre and polyvinyl alcohol (PVA) fibre were found to be beneficial to the strength of recycled coarse aggregate concrete (RCAC), but the effects in the fracture properties of the RCAC has been overlooked. This study added PP fibre and PVA fibre to enhance the ability of the RCAC to resist crack instability expansion. The three-point bending tests were performed to compare the fracture properties of the RCAC with fibres and without fibre. The reinforcement mechanism of fibres was analyzed by the single-fibre pullout tests and scanning electron microscopy tests. The experimental results indicated that fibres could not effectively increase the compressive strength of RCAC but the splitting tensile strength of RCAC was significantly improved with the increase of the volume fraction of fibres and the optimal volume fraction of fibre was 1.5% PP fibre. The PP fibre and PVA fibre both effectively improved the fracture properties of RCAC but acted in the post-cracking stage and the linear loading stage, respectively. As a concrete manifestation of the PP fibre was more effective in increasing the peak load, unstable toughness, and fracture energy of RCAC than the PVA fibre while the PVA fibre was more effective in increasing the initial cracking load and the initial toughness. The 1.0% PP fibre had the best effect on the fracture properties, which increased peak load, unstable toughness, and fracture energy by 47.2%, 42.3%, and 5500%, respectively. The 0.2% PVA has the best effect on the fracture properties of RCAC at the stage before the cracks developed which increased initial cracking load and initial toughness by 25.2% and 43.7%, respectively. In addition, the development of cracks of RCAC with PP fibre was more tortuous than that of RCAC with PVA fibre. A reinforcement mechanism analysis showed that there were obvious diamond-shaped depressions on the surface of PP fibre which provided mechanical interlock to enhance the RCAC. The hydrogen bonds of PVA fibre also enhanced the RCAC through the hydration products attached to the surface of the PVA but it is weaker than diamond-shaped depressions. These results provided theoretical and experimental support for the research gap of PP fibre and PVA fibre in RCAC.
Keyword ：
Crack propagation Crack propagation Fracture energy Fracture energy Fracture toughness Fracture toughness Mechanism analysis Mechanism analysis Polypropylene fibre Polypropylene fibre Polyvinyl alcohol fibre Polyvinyl alcohol fibre Recycled coarse aggregate concrete Recycled coarse aggregate concrete
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| GB/T 7714 | Lin, Qian , Luo, Surong , Lin, Kaida et al. Effects of synthetic fibres on the fracture behaviours of recycled coarse aggregate concrete [J]. | CONSTRUCTION AND BUILDING MATERIALS , 2024 , 418 . |
| MLA | Lin, Qian et al. "Effects of synthetic fibres on the fracture behaviours of recycled coarse aggregate concrete" . | CONSTRUCTION AND BUILDING MATERIALS 418 (2024) . |
| APA | Lin, Qian , Luo, Surong , Lin, Kaida , Wang, Dehui . Effects of synthetic fibres on the fracture behaviours of recycled coarse aggregate concrete . | CONSTRUCTION AND BUILDING MATERIALS , 2024 , 418 . |
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通过10组试验，研究了10%～30%粉煤灰、 10%～30%矿渣、 5%～15%偏高岭土在单掺下对海水海砂混凝土抗氯离子渗透性能及化学组成的影响，并通过扫描电镜对微观结构进行分析.结果表明：海水海砂混凝土氯离子扩散系数随着粉煤灰掺量提高先减少后增大，随着矿渣掺量提高逐渐增大，随着偏高岭土掺量提高逐渐减小；偏高岭土、矿渣和20%以下粉煤灰掺入海水海砂混凝土后，均可见随着掺量的提高混凝土中的Friedel盐增多，自由氯离子及Ca(OH)_2含量降低，混凝土孔溶液pH值降低；偏高岭土对海水海砂混凝土的氯离子化学结合和物理吸附作用及微观结构的改善最佳，20%以内掺量的粉煤灰次之.
Keyword ：
微观结构 微观结构 抗氯离子渗透性能 抗氯离子渗透性能 海水海砂混凝土 海水海砂混凝土 矿物掺和料 矿物掺和料
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| GB/T 7714 | 余海玲 , 郑建岚 , 王国杰 et al. 矿物掺和料对海水海砂混凝土抗氯离子渗透性的影响 [J]. | 福州大学学报(自然科学版) , 2024 , 52 (03) : 284-290 . |
| MLA | 余海玲 et al. "矿物掺和料对海水海砂混凝土抗氯离子渗透性的影响" . | 福州大学学报(自然科学版) 52 . 03 (2024) : 284-290 . |
| APA | 余海玲 , 郑建岚 , 王国杰 , 王德辉 . 矿物掺和料对海水海砂混凝土抗氯离子渗透性的影响 . | 福州大学学报(自然科学版) , 2024 , 52 (03) , 284-290 . |
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The shortages of river sand and freshwater in marine engineering can be addressed by utilizing seawater and sea sand concrete (SWSSC). However, the sulfate resistance of SWSSC at low temperature is not clear. In this study, the seawater and sea sand cement mortar (SSCM) and ordinary cement mortar (OCM) with different limestone powder (LP) content were corroded by different sulfate solutions at 5 °C. The change of compressive strength and compositions of corrosion products in mortars after different times of corrosion were studied. The results show that SSCM presents 9.4∼19 % lower strength loss and better sulfate resistance than OCM. The presence of Friedel's salt in SSCM contributes to a reduction in corrosion products like ettringite, gypsum, and thaumasite, thereby minimizing microstructural damage and mitigating the thaumasite sulfate attack (TSA). All mortars containing LP suffer from TSA and significantly damage with 17.4∼48.7 % strength loss after 360 days of MgSO4 or Na2SO4 corrosion. Increasing the LP content exacerbates the TSA damage in SSCM. This is primarily due to the additional soluble carbonate from LP promoting the formation of gypsum and thaumasite, thereby worsening the microstructure deterioration of SSCM. Meanwhile, the thaumasite is not found in SSCM without LP after corrosion. In contrast to Na2SO4 corrosion, the thaumasite formation under MgSO4 corrosion mainly results from indirect reaction. The combined corrosion effects of Mg2+ and SO42- lead to a more significant increase in expansive products (thaumasite and gypsum) and TSA damage. The findings of this study help to advance the sulfate resistance of SWSSC in marine environments. © 2024 Elsevier Ltd
Keyword ：
Cements Cements Compressive strength Compressive strength Concretes Concretes Corrosive effects Corrosive effects Deterioration Deterioration Lime Lime Limestone Limestone Magnesium compounds Magnesium compounds Sand Sand Seawater corrosion Seawater corrosion Silicate minerals Silicate minerals Sodium sulfate Sodium sulfate Temperature Temperature
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| GB/T 7714 | Wang, Dehui , Zhang, Zhiwen , Chen, Rong et al. Thaumasite sulfate attack characteristic of seawater and sea sand concrete with limestone powder in different sulfate environment at low temperature [J]. | Construction and Building Materials , 2024 , 437 . |
| MLA | Wang, Dehui et al. "Thaumasite sulfate attack characteristic of seawater and sea sand concrete with limestone powder in different sulfate environment at low temperature" . | Construction and Building Materials 437 (2024) . |
| APA | Wang, Dehui , Zhang, Zhiwen , Chen, Rong , Wang, Ming , Chen, Ran , Weng, Lincheng et al. Thaumasite sulfate attack characteristic of seawater and sea sand concrete with limestone powder in different sulfate environment at low temperature . | Construction and Building Materials , 2024 , 437 . |
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玉米芯具有较低的导热系数,可以作为天然的保温材料,用于混凝土砌块中。然而,由于玉米芯的多孔结构,导致玉米芯骨料混凝土的抗压强度偏低,亟需进行改性。为了推广玉米芯的规模化利用,该研究以玉米芯为原料改善混凝土砌块的性能,通过红外光谱、拉曼光谱和扫描电镜等测试手段,探讨了3种不同改性技术对玉米芯骨料混凝土水化产物化学键、分子结构、界面过渡区微观结构、抗压强度和导热系数的影响。结果表明:与环氧树脂改性相比,陶粒法改性和裹浆法改性不仅增加了玉米芯骨料混凝土界面过渡区的水化硅酸钙凝胶含量,同时也降低了界面过渡区的厚度,优化了混凝土砌块的微观结构、提高了混凝土砌块的抗压强度、降低了混凝土砌块的导热系数。其中,陶粒法改性技术的效果尤为明显。界面过渡区厚度水化硅酸钙特征峰由大到小顺序分别为陶粒法改性、裹浆法改性、环氧树脂改性。经过陶粒法改性、裹浆法改性和环氧树脂改性后,玉米芯骨料混凝土的界面过渡区分别为无明显界面过渡区、55～66 μm和93～101 μm之间。和未改性玉米芯骨料混凝土相比,掺30%陶粒法改性玉米芯骨料混凝土的抗压强度的导热系数分别降低了51.5%和32.2%。当掺入不超过15%的改性玉米芯骨料时,混凝土砌块满足国家标准GB/T8239-2014中对抗压强度的要求。为了改善玉米芯骨料混凝土砌块的综合性能,建议掺入不超过15%的陶粒法改性玉米芯骨料。研究结果为玉米芯在混凝土砌块中的大规模利用提供了依据,同时也为进一步改善混凝土砌块的相关性能提供了参考。
Keyword ：
导热系数 导热系数 抗压强度 抗压强度 改性技术 改性技术 水化产物 水化产物 玉米芯 玉米芯 界面过渡区 界面过渡区
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| GB/T 7714 | 范炜 , 刘国超 , 陈龙辉 et al. 不同化学改性方法提高玉米芯骨料混凝土的性能 [J]. | 农业工程学报 , 2024 , 40 (11) : 220-226 . |
| MLA | 范炜 et al. "不同化学改性方法提高玉米芯骨料混凝土的性能" . | 农业工程学报 40 . 11 (2024) : 220-226 . |
| APA | 范炜 , 刘国超 , 陈龙辉 , 王德辉 . 不同化学改性方法提高玉米芯骨料混凝土的性能 . | 农业工程学报 , 2024 , 40 (11) , 220-226 . |
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The compressive strength data of 3D printed concrete (3DPC) in X (Print direction), Y (Adjacent stripes), and Z (Stacked stripes) were collected and analyzed to evaluate its anisotropic behavior and statistical parameters. Similar to conventional cast concrete, there is a linear relationship between the compressive strength of 3DPC and the binder-to-water ratio (B/W). For the normalized strength data, the average ratios of X/C, Y/C, and Z/C at 28 days are 0.87, 0.80, and 0.82 respectively, indicating a decrease in the compressive strength and anisotropy compared to cast concrete. Compared to the coefficient of variation (COV) of cast specimens mentioned in the specifications, there is an increase of 4.3–69 %. The weak interfaces and unique pore shapes in 3DPC interact to cause stress concentration and redistribution of internal stresses, resulting in decreased compressive strength, anisotropy, and variability. This investigation can provide material parameters for studying the structural performance of 3DPC components. © 2024
Keyword ：
3D printing 3D printing Anisotropy Anisotropy Compressive strength Compressive strength
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| GB/T 7714 | Zhang, Kaijian , Lin, Wenqiang , Zhang, Qingtian et al. Evaluation of anisotropy and statistical parameters of compressive strength for 3D printed concrete [J]. | Construction and Building Materials , 2024 , 440 . |
| MLA | Zhang, Kaijian et al. "Evaluation of anisotropy and statistical parameters of compressive strength for 3D printed concrete" . | Construction and Building Materials 440 (2024) . |
| APA | Zhang, Kaijian , Lin, Wenqiang , Zhang, Qingtian , Wang, Dehui , Luo, Surong . Evaluation of anisotropy and statistical parameters of compressive strength for 3D printed concrete . | Construction and Building Materials , 2024 , 440 . |
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To deepen the application and development of 3D Printing Construction Technology, the rheological characteristics, compressive strength and bending performance of 3D printed polyvinyl alcohol fiber (PVA fiber) reinforced cement-based material were explored. The direction of the intralayer interfaces and the fiber's distribution direction caused the anisotropy of 3D printed PVA fiber reinforced cement-based material. The printed specimens presented different failure patterns in different compressive directions, and there was certain anisotropy in the X, Y and Z directions. For the bending performance, the load-midpoint deflection curves of casted specimens and the Z(x) direction of printed specimens showed the strain hardening behavior, while the Z(y) direction of printed specimens did not. Compared with the Z(y) specimen, the bending strength of the Z(x) specimen was about 3 similar to 4 times higher, and the peak deflection was about an order of magnitude higher. The anisotropy of the printed specimen can be used to improve the bending performance in a specific loading direction to a certain extent.
Keyword ：
3D printing technology 3D printing technology Anisotropy Anisotropy Bending performance Bending performance Compressive strength Compressive strength Rheological characteristics Rheological characteristics
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| GB/T 7714 | Luo, Surong , Li, Wenqiang , Wang, Dehui . Study on bending performance of 3D printed PVA fiber reinforced cement-based material [J]. | CONSTRUCTION AND BUILDING MATERIALS , 2024 , 433 . |
| MLA | Luo, Surong et al. "Study on bending performance of 3D printed PVA fiber reinforced cement-based material" . | CONSTRUCTION AND BUILDING MATERIALS 433 (2024) . |
| APA | Luo, Surong , Li, Wenqiang , Wang, Dehui . Study on bending performance of 3D printed PVA fiber reinforced cement-based material . | CONSTRUCTION AND BUILDING MATERIALS , 2024 , 433 . |
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弹性模量是混凝土结构设计中非常重要的参数，原材料组成对混凝土的弹性模量具有显著的影响。通过宏观弹性模量分析、XRD、纳米压痕分析了不同原材料组成对超高性能混凝土(UHPC)弹性模量的影响。结果表明：各胶凝组成下75%水泥+25%硅灰组的超高性能混凝土试件在弹性模量、水化产物种类、数量、纳米力学性能及水化程度等指标中表现最优。在一定范围内，降低浆集比和水胶比均能提高UHPC的弹性模量。为提高UHPC的高弹性模量，建议浆集比和水胶比分别为1∶1.25和0.18。
Keyword ：
弹性模量 弹性模量 水胶比 水胶比 浆集比 浆集比 胶凝组成 胶凝组成 超高性能混凝土 超高性能混凝土
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| GB/T 7714 | 李一帆 , 余崇文 , 王德辉 . 原材料组成对超高性能混凝土弹性模量的影响 [J]. | 武汉理工大学学报 , 2024 , 46 (07) : 8-14 . |
| MLA | 李一帆 et al. "原材料组成对超高性能混凝土弹性模量的影响" . | 武汉理工大学学报 46 . 07 (2024) : 8-14 . |
| APA | 李一帆 , 余崇文 , 王德辉 . 原材料组成对超高性能混凝土弹性模量的影响 . | 武汉理工大学学报 , 2024 , 46 (07) , 8-14 . |
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