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2023
Volume: 51 Issue 11
26 Article(s)
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Effect of Boron/Phosphorus Compound Doping on Formation and Properties of Sulfate-Rich Belite Sulfoaluminate Clinker
ZHANG Wensheng, AN Nan, ZHANG Hongtao, REN Xuehong... and QIAN Jueshi|Show fewer author(s)
Sulfate-rich belite sulfoaluminate cement is used in rapid construction of marine engineering, but the strength of the clinker developed is not enough in the later period. The improvement of the strength in the later stage was investigated via boron/phosphorus composite doping. The effect of boron/phosphorus composite Sulfate-rich belite sulfoaluminate cement is used in rapid construction of marine engineering, but the strength of the clinker developed is not enough in the later period. The improvement of the strength in the later stage was investigated via boron/phosphorus composite doping. The effect of boron/phosphorus composite doping on the mineral formation, microstructure, and hydration of high sulfur belite aluminate clinker was analyzed by X-ray diffraction combined with Rietveld full spectrum quantitative analysis, scanning electron microscopy, isothermal calorimetry and thermogravimetric analysis. The results show that boron and phosphorus both can exist in the crystal structure of dicalcium silicate, form the crystal defects, and increase the content of α-C2S and c-C4A3$, thus promoting the early hydration and later strength development of the clinker..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2741 (2023)
Bond Performance Between Seawater Sea-Sand Alkali Activated Concrete and FRP Bars
CUI Yifei, QU Shihao, and ZHANG Peng
To investigate the bond performance between seawater sea-sand alkali activated concrete (SSASC) and carbon fiber-reinforced polymer (CFRP)/glass fiber-reinforced polymer (GFRP) bars, center pull-out tests were carried out at different FRP bars, FRP bars diameters, bond lengths, concrete strengths, and concrete curing aTo investigate the bond performance between seawater sea-sand alkali activated concrete (SSASC) and carbon fiber-reinforced polymer (CFRP)/glass fiber-reinforced polymer (GFRP) bars, center pull-out tests were carried out at different FRP bars, FRP bars diameters, bond lengths, concrete strengths, and concrete curing ages. Based on the statistical analysis of existing experimental data, the bonding performance between alkali activated concrete (ASC) and FRP bars is significantly better than that of ordinary Portland concrete (OPC). The bond strength can be predicted by the corresponding empirical model. The results show that the bond strength decreases with the increase of FRP bars’ diameter and bond length, and there is no significant change as the diameter changes. Concrete ASC30 is mostly destroyed in pull-out failure, while concrete ASC60 is mostly destroyed in splitting/reinforcement fracture failure, and the concrete with a higher strength also has a higher bond strength. The bond strength increases with the increase of curing age. The bond strength between OPC and FRP bars is less than that of ASC. In addition, the bond strength predicted by the empirical model is in reasonable agreement with the experimental data..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2750 (2023)
Influence of NaAlO2 on Hydration and Property of Mussel Shell-Based Carbonaluminate Cementitious Materials
LIU Yuantao, DONG Biqin, XING Feng, and WANG Yanshuai
Ocean is a largest carbon reservoir in the Earth, and the total production of marine shellfish in China is huge. Most of shellfish only utilizes their edible value, and shells are randomly stacked or buried as a solid waste. To improve the utilization rate of shellfish waste, the effect of NaAlO2 on the hydration proceOcean is a largest carbon reservoir in the Earth, and the total production of marine shellfish in China is huge. Most of shellfish only utilizes their edible value, and shells are randomly stacked or buried as a solid waste. To improve the utilization rate of shellfish waste, the effect of NaAlO2 on the hydration process, solid-liquid phase composition, pore structure and mechanical property of the shell powder-calcium aluminate cementitious system was investigated. The results show that NaAlO2 enables accelerating the hydration process, shortening the setting time, and slightly improving the compactness and mechanical properties of the hardened matrix. NaAlO2 affects the solid-liquid phase composition. Adding NaAlO2 increases the alkalinity of the pore solution and improves the reactivity of CaCO3, leading such a cementitious system to the formation of a stable phase (i.e., monocarboaluminate (C4AcH11)) with a reduced amount of the unstable phase (i.e., calcium aluminate hydrate (CAH10)). The samples with 3.75‰ and 5.00‰ of NaAlO2 produce 13.0% and 13.6% of C4AcH11, respectively, and no CAH10 phase occurs after cured for 28 d. The crystallite size of the microcrystalline AH3 phase grows, which compromises the cementitious property because NaAlO2 increases the alkalinity. The excessive NaAlO2 leads to a decreased mechanical property. Mussel shell-based carbonaluminate cementitions materials hold promise in marine civil engineering construction..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2763 (2023)
Fabrication and Properties of Plasma Sprayed Calcium Magnesium Aluminum Silicate Ceramic Coatings
WANG Zhiping, CAO Yuhan, CHENG Taotao, LUO Zhen, and LIU Weidong
A CaO-MgO-Al2O3-SiO2 amorphous ceramic material was fabricated by a high-temperature melting method, and calcium magnesium aluminum silicate ceramic coating was prepared on 45# steel substrate via high-speed grinding and plasma spraying. The phase composition, microhardness, and microstructure of monolithic ceramics anA CaO-MgO-Al2O3-SiO2 amorphous ceramic material was fabricated by a high-temperature melting method, and calcium magnesium aluminum silicate ceramic coating was prepared on 45# steel substrate via high-speed grinding and plasma spraying. The phase composition, microhardness, and microstructure of monolithic ceramics and coatings were analyzed, and the bonding strength of the coatings was tested through tensile experiments. The corrosion resistance and mechanism of the coating were investigated through salt solution immersion corrosion experiments. The results indicate that the porosity of the calcium magnesium aluminum silicate ceramic coating is 7.93%±3.27%, without an obvious layered structure. The microhardness value of the coating is 6.63 GPa, which is only 3.89% lower than that of monolithic materials. The non-porous area has the microstructure and mechanical properties of monolithic ceramic materials. The bonding strength of the coating is (16.25±2.11) MPa, and the fracture occurs at the interface between the coating and the metal transition layer, which is equivalent to the bonding performance of other plasma spraying ceramic coatings. The corrosion rate of the coated sample is 0.102 6?偆bg瘙簚m-2瘙簚h-1, which is reduced by 12.3 times, compared to the substrate sample, indicating a good corrosion resistance through a 1 000?偆bh-immersion-corrosion-experiment. Based on the analysis of the corrosion cross-section, the dense structure of the coating plays a mechanical isolation role in corrosion. The dissolution rate of corrosion products accumulated on the pores and crack surfaces of the coating is balanced with the rate of corrosion liquid penetrating into the substrate, reducing the corrosion..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2780 (2023)
Corrosion Behavior of Steel in Cement-Bagasse Ash-Slag Sea-Sand Mortar
MO Yaohong, LIU Jianhui, LIU Leping, CHEN Zheng, and SHI Caijun
Effect of cement mixture containing bagasse ash (SCBA) and slag (BFS) on the corrosion properties of steel in sea-sand mortar was investigated. The electrochemical impedance spectra, open circuit potential, and corrosion current density of steel were determined, and the chloride ions content, pH value and hydration proEffect of cement mixture containing bagasse ash (SCBA) and slag (BFS) on the corrosion properties of steel in sea-sand mortar was investigated. The electrochemical impedance spectra, open circuit potential, and corrosion current density of steel were determined, and the chloride ions content, pH value and hydration products were measured. The results show that an increase in bagasse ash content leads to an increase in the corrosion rate of steel and [Cl-]/[OH-] value. However, an increase in slag content can reduce the corrosion rate of steel, and cause that the [Cl-]/[OH-] value initially increases and slightly decreases after 28 d. The addition of 15% bagasse ash and 15% slag has a positive synergistic effect, effectively increasing the resistance of mortar protective layer and charge transfer resistance, improving the stability of the passivation film, and reducing the corrosion rate of steel in the mortar by 31.86%, compared to the reference group. The optimum corrosion resistance of the steel can be obtained. It is indicated that the use of a cement mixture containing bagasse ash and slag can effectively improve the corrosion resistance of steel in sea-sand mortar..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2792 (2023)
Chloride Diffusion Properties of Cement Mortar Under Salt Spray Wetting-Drying Cycle
YUAN Qiang, WANG Yuman, ZHANG Kai, ZHANG Jiajia... and ZHANG Zhipeng|Show fewer author(s)
The deterioration of the durability of marine concrete and the degree of corrosion of internal steel bars in the tidal, splash and atmospheric zones are often serious in salt spray wetting and drying cycle. The diffusion of chloride in cement-based materials was investigated at different parameters (i.e., mix ratio, drThe deterioration of the durability of marine concrete and the degree of corrosion of internal steel bars in the tidal, splash and atmospheric zones are often serious in salt spray wetting and drying cycle. The diffusion of chloride in cement-based materials was investigated at different parameters (i.e., mix ratio, dry-wet ratio, and exposure time) by a cycle test of salt spray wetting and drying and a test method of layered grinding and potentiometric titration. The results show that the deposition and transport of chloride ions in mortar are primarily affected by salt spray wetting-drying cycle, dry-wet ratio, water-binder ratio, and exposure period. The influence of water-binder ratio is dominant, while the influence of dry-wet ratio is slight. The maximum concentration of chloride Cmax and the effective chloride diffusion coefficient Deff increase as water-binder ratio improves. Cmax firstly increases and subsequently declines as fly ash amount and frequency of dry-wet cycles increase. Deff decreases as exposure time increases. Deff firstly increases and subsequently reduces as fly ash content increases. Low water-binder ratio and use of fly ash can effectively postpone chloride erosion, thereby enhancing the durability of structures..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2805 (2023)
Triaxial Mechanical Properties of Coral Seawater Sea Sand Concrete
CHEN Yuliang, LI Peize, and CHEN Zongping
To analyze the triaxial mechanical properties of coral seawater sea sand concrete, the effects of aggregate and lateral confining pressure on the failure mode, stress-strain curve, yield stress, yield strain, and damage evolution of specimens were investigated via conventional triaxial tests. The results show that the To analyze the triaxial mechanical properties of coral seawater sea sand concrete, the effects of aggregate and lateral confining pressure on the failure mode, stress-strain curve, yield stress, yield strain, and damage evolution of specimens were investigated via conventional triaxial tests. The results show that the coral coarse aggregate specimen is more susceptible to the influence of confining pressure value. The cracks form transformation and plastic flow appear on the surface of the specimen at a confining pressure value of 9 MPa. The stress-strain curve appears a stress platform section' at a confining pressure value of 12 MPa, while the gravel coarse aggregate specimen appears the above changes at confining pressure values of 15 MPa and 24 MPa, respectively. After a confining pressure value reaches 15 MPa, the stress-strain curve of the coral coarse aggregate specimen shows a bilinear shape with a second linear branch. The dissipation energy of the specimens gradually increases and the damage development gradually delays with the increase of confining pressure, yield stress and yield strain. In addition, the yield stress calculation formula of coral seawater sea sand concrete was aslo proposed, thus providing a reference for the relevant theoretical analysis and engineering application..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2814 (2023)
Hygro-Mechanical Coupling of Solid Buoyancy Materials
GAO Bo, WANG Fang, JIANG Zhe, WANG Jingze... and CUI Weicheng|Show fewer author(s)
Solid buoyancy material is an important material for manned/unmanned deep submersibles due to its low density and high compressive strength. Hollow glass microspheres in solid buoyancy materials will gradually damage at a high pressure, leading to an increase in water absorption and thereby reducing the positive buoyanSolid buoyancy material is an important material for manned/unmanned deep submersibles due to its low density and high compressive strength. Hollow glass microspheres in solid buoyancy materials will gradually damage at a high pressure, leading to an increase in water absorption and thereby reducing the positive buoyancy of the submersible and affecting the safety and usability of manned/unmanned deep submersibles. There is a coupling relationship between water absorption rate and stress of buoyancy materials, which poses challenges in calculating the water absorption rate of buoyancy materials. This paper was to investigate concentric spherical shell cells and analyze the entire water absorption process via adding subroutines by a finite element method (FEM). The distribution, changes, and interrelationships of bulk stress, water absorption rate, and diffusion coefficient of buoyancy materials at different thickness points and durations were analyzed. It is indicated that water absorption rate is linearly related to bulk stress, and the expansion coefficient is related to bulk stress. The results calculated by the finite element analysis are in reasonable agreement with the experimental data. The paper can provide a theoretical guidance for the design and application of solid buoyancy materials at sea depths..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2824 (2023)
Effect of Mixing with Seawater and Metakaolin on Hydration of Ferroaluminate Cement
LIAO Yishun, YE Jian, and TANG Shengwen
Ferroaluminate cement has an effective resistance to seawater erosion due to its advantages in the application of marine engineering. The effect of mixing with seawater and metakaolin on the fluidity, setting time, heat of hydration, electrical resistivity, internal temperature, chemical shrinkage, compressive strengthFerroaluminate cement has an effective resistance to seawater erosion due to its advantages in the application of marine engineering. The effect of mixing with seawater and metakaolin on the fluidity, setting time, heat of hydration, electrical resistivity, internal temperature, chemical shrinkage, compressive strength, and hydration products of ferroaluminate cement paste was investigated. The results indicate that the addition of metakaolin reduces the fluidity and shortens the setting time of the cement paste. The chemical shrinkage at 72 h, electrical resistivity and internal temperature peak at 24 h all decrease. However, the heat release rate, chemical shrinkage, electrical resistivity and the formation of ettringite at early age can be accelerated when the content of metakaolin is less than 20%. When the cement is mixed with seawater, the hydration of cement can be accelerated and the fluidity and setting time can be decreased. The formation of the Friedel’s salt can occur. The mixing of seawater and appropriate amounts of metakaolin in ferroaluminate cement promotes more ettringite, thus increasing the compressive strength of ferroaluminate cement paste. The compressive strength of different specimens mixed seawater at 180 d is improved by 48.6%-80.2%, compared to that of the sample mixed with fresh water..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2834 (2023)
Chloride Permeability Evaluation of Concretes in Marine Environment
LIU Zhen
In marine environment, complex environmental factors such as temperature and dry-wet cycles accelerate the transmission process of chloride in concrete, thus affecting the durability of concrete structures. It is of great significance to strengthen the research on the durability evaluation of concrete in this special cIn marine environment, complex environmental factors such as temperature and dry-wet cycles accelerate the transmission process of chloride in concrete, thus affecting the durability of concrete structures. It is of great significance to strengthen the research on the durability evaluation of concrete in this special corrosive environment. At present, a single index (i.e., chloride diffusion coefficient) is usually used to quantify the influence of environmental factors on the durability of concrete, which cannot comprehensively reflect the influence of environmental factors on the chloride ion transport process. Based on the Fick second law, we derived an analytical solution of the total amount of chloride ions entering the concrete from the diffusion flux, as the accumulated content of chloride. For the cumulative content of chloride, the quantitative index 'l value' of concrete chloride permeability was established, and then the comprehensive evaluation method of concrete durability was constructed when the two typical marine environmental factors of temperature and dry-wet cycle were concerned. The influence of environmental factors such as temperature and dry-wet cycle on the l value of concrete was analyzed. A linear relationship between the 28-d apparent chloride diffusion coefficient D28 and the maximum monthly average temperature Tmax and a linear relationship between the age coefficient m and the annual temperature difference ΔTy were revealed. Subsequently, a simplified calculation formula for the quantitative index l value of concrete chloride ion permeability with respect of effects like dry-wet cycle and temperature was proposed. This formula is suitable for evaluating the influence of complex environmental factors (i.e., temperature and dry-wet cycle) on the concrete chloride permeability..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2846 (2023)
Preparation of Modified Polyacrylate Emulsion and Durability Evaluation of Polymer Cement-Based Coating
LU Shuo, JIANG Dongbing, LI Qiqi, HOU Pengkun... and ZHAO Piqi|Show fewer author(s)
Hydrophobic modification of cement-based coating is beneficial to improving its protective effect, but it leads to poor dispersion of coating, weakening of physical properties and durability of coating. In this paper, a highly stable/hydrophobic modified polyacrylate emulsion was prepared by using hydroxy-containing poHydrophobic modification of cement-based coating is beneficial to improving its protective effect, but it leads to poor dispersion of coating, weakening of physical properties and durability of coating. In this paper, a highly stable/hydrophobic modified polyacrylate emulsion was prepared by using hydroxy-containing polydimethylsiloxane (PDMS) as a second oil phase, and a high durability polymer cement-based protective coating was further constructed. The modified emulsions with good stability and hydrophobicity can be obtained by matching the molecular weight and dosage of PDMS and emulsifying the shear rate. Little stratification occurs after 30 d, the contact angle of latex film is increased by 24.9%, and the water absorption is decreased by 28.94%. The prepared polymer cement-based coating has superior mechanical properties, hydrophobicity, UV aging resistance, seawater and alkali immersion resistance, and the chloride ion permeability coefficient is only 0.193×10-6 mm2/s. In addition, the modification mechanism of emulsion and the durability enhancement mechanism of coating were also analyzed..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2857 (2023)
Recent Development on Batteries of Deep-Sea Submersibles
YUAN Zhixiang, ZHANG Hao, ZHANG Xue, YANG Zhilin... and CUI Guanglei|Show fewer author(s)
The deep-sea contains an abundant of natural resources and treasures that still remain unrecognized and unexploited. To obtain these resources, developing advanced submersibles that are able to explore the deep-sea becomes a challenge. In the extreme harsh environment such as ultra-high pressure and low temperature in The deep-sea contains an abundant of natural resources and treasures that still remain unrecognized and unexploited. To obtain these resources, developing advanced submersibles that are able to explore the deep-sea becomes a challenge. In the extreme harsh environment such as ultra-high pressure and low temperature in the deep sea, the advanced deep-sea submersibles have to be reliable and stable. In this regard, a power supply system is extremely important for the deep-sea submersibles because its performance directly affects the operation capability, safety and reliability of the deep-sea submersible. Therefore, recent efforts have been devoted to the development of deep-sea power sources. The existing deep-sea power systems have experienced the development stages of lead-acid batteries, silver-zinc batteries, lithium-ion batteries, and high-energy-density solid-state lithium batteries. This review elaborated the main classification of deep-sea power sources. In addition, the challenges and future development trends of batteries for deep-sea submersibles were also discussed. It is expected that this review could provide a reference for the further development of the power supply systems for more reliable and advanced deep-sea submersibles..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2868 (2023)
Corrosion Resistance of Cement-based Materials by Carbonation Curing to Carbonic Acid Solution
LAI Chuanglin, LIU Leping, LIU Jianhui, CHEN Zheng... and SHI Caijun|Show fewer author(s)
Effect of carbonation curing on the early resistance to carbonic acid solution corrosion of cement-based materials was investigated. The compressive strength, and corrosion depth of carbonation cured specimens were tested after immersion in carbonic acid water for varying periods. The microstructure and corrosion mechaEffect of carbonation curing on the early resistance to carbonic acid solution corrosion of cement-based materials was investigated. The compressive strength, and corrosion depth of carbonation cured specimens were tested after immersion in carbonic acid water for varying periods. The microstructure and corrosion mechanisms were analyzed by X-ray diffraction, thermogravimetric analysis, low-field nuclear magnetic resonance, and scanning electron microscopy. The results show that carbonation curing improves the initial compressive strength via forming calcite to fill pores, making the structure more compact and hindering inward diffusion rate of carbonic acid solution. A dense, slower-dissolving calcite layer around C-S-H gel reduces calcium-corrosion, decreasing both the corrosion depth of mortar specimens by 51%-68% after 90-d immersion and losing the strength after carbonic acid water corrosion. The early-stage corrosion was dominated due to C3S, C2S, and CH corrosion, accompanied by CaCO3 decalcification. The middle- and later-stage corrosion involves the decalcification of CaCO3 and C-S-H gel..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2890 (2023)
Rheology and Strength of Silane Modified Ultra-High Performance Concrete
, , , ... and |Show fewer author(s)
To reduce the viscosity and promote the workability of ultra-high performance concrete (UHPC), this paper selected aminosilane (KH550) with a hydrophilic functional group as auxiliary admixtures for UHPC mixtures. The effects of the mixture ratio and dosage of hydrolyzed silane on the mechanical properties and rheologyTo reduce the viscosity and promote the workability of ultra-high performance concrete (UHPC), this paper selected aminosilane (KH550) with a hydrophilic functional group as auxiliary admixtures for UHPC mixtures. The effects of the mixture ratio and dosage of hydrolyzed silane on the mechanical properties and rheology of UHPC were investigated. The silane modification mechanism of UHPC was discussed. The results show that KH550 is suitable for hydrolysis in the mixed solvent of anhydrous ethanol and deionized water (or tap water). The optimum hydrolysis ratio (mass ratio) is determined as m1 (KH550): m2 (deionized water or tap water): m3 (anhydrous ethanol)=1.0:3.0:(2.5-5.0). The hydrolysis process is carried out under stirring for 3 min and hydrolyzed for more than 2 h. The optimum silane content in UHPC (calculated according to a mass ratio with silica fume in UHPC) is 1%. The Bingham model can be used to describe the rheological behavior of fresh UHPC modified by hydrolyzed silane. The rheological properties of fresh UHPC modified by hydrolyzed silane are improved, but the effect on the mechanical properties is ignored..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2914 (2023)
Decalcification Behavior of Calcium Silicate Hydrate with Different Ca/Si Ratios
ZHANG Ziwei, LIU Zhentao, and LI Guoxin
This paper was to synthesize C-S-H with different Ca/Si ratios by a hydrothermal synthesis method, and decalcify it using 6 mol/L NH4Cl solutions. The chemical composition, chain structure and microstructure were analyzed. The results show that C-S-H is a gel structure formed by irregular aggregates. The content of dimThis paper was to synthesize C-S-H with different Ca/Si ratios by a hydrothermal synthesis method, and decalcify it using 6 mol/L NH4Cl solutions. The chemical composition, chain structure and microstructure were analyzed. The results show that C-S-H is a gel structure formed by irregular aggregates. The content of dimer and chain end groups in C-S-H increases, while the average degree of polymerization and average chain length decreases with the increase of Ca/Si ratio. The change of C-S-H structure includes decreased interlayer distance, cross-linked silicate chains, and amorphous silica gels formed after decalcification, resulting in the loss of C-S-H cohesion..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2924 (2023)
Dynamic Mechanical Properties of Silica Nanoparticles Reinforced Coral Sand Cement Mortar Under Confining Pressure
GUO Ruiqi, XU Xin, REN Huiqi, YOU Qi... and LIU Bing|Show fewer author(s)
A coral sand cement mortar was prepared with 2.0% SiO2 nanoparticles, 0.4% basalt fiber and artificial seawater. The impact compression strength of the samples at different confining pressures (i.e., 0-20 MPa) was determined by using a split Hopkinson pressure bar with an active confining pressure device. The dynamic mA coral sand cement mortar was prepared with 2.0% SiO2 nanoparticles, 0.4% basalt fiber and artificial seawater. The impact compression strength of the samples at different confining pressures (i.e., 0-20 MPa) was determined by using a split Hopkinson pressure bar with an active confining pressure device. The dynamic mechanical properties of SiO2 nanoparticles reinforced coral sand cement mortar were analyzed at different confining pressures and strain rates. The results show that the failure pattern of unconfined (uniaxial impact) specimens occurs, indicating the brittle characteristics. The better integrity of the specimen after being impacted appears under the active confinement, which belongs to a compressive-shear failure. Moreover, the specimen undergoes a transition from brittle to plastic, thus improving the toughness. From the obtained dynamic stress-strain curve, the strength of the specimen is increased by 2.08-3.43 times, compared to that under static conditions, and the dynamic compressive strength is 1.88-2.35 times greater than that of unconfined (uniaxial impact) specimens. The relevant empirical formulas were obtained via analyzing the dynamic increase factor and confinement increase factor of the material and their corresponding effects on strain rate and confining pressure variation. At the same confining pressure, the specific energy absorption of materials shows a linear increase with the incident wave energy. Through the analysis of energy dissipation, the confining pressure can increase the specific energy absorption value of SiO2 nanoparticles reinforced coral cement mortar..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2931 (2023)
Migration of Chloride Ions in Cement-based Materials in Carbonic Acid Solution Environment
WEI Junfeng, LIU Leping, LIU Jianhui, CHEN Zheng... and SHI Caijun|Show fewer author(s)
When the groundwater contains a high concentration of carbonate and chloride ions, the corrosion of carbonic acid solution on underground concrete structures will lead to a faster migration of chloride ions in concrete. Migration characteristic of chloride ions in mortar exists in carbonic acid solution environment. ThWhen the groundwater contains a high concentration of carbonate and chloride ions, the corrosion of carbonic acid solution on underground concrete structures will lead to a faster migration of chloride ions in concrete. Migration characteristic of chloride ions in mortar exists in carbonic acid solution environment. The corrosion products and microstructure of paste under the attack of carbonic acid solution and chloride ions were analyzed by X-ray diffraction (XRD), thermogravimetric analysis (TG-DTG) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). The results show that in the early stage of carbonic acid water corrosion, calcium hydroxide and C-S-H gel decalcifies to form calcium carbonate filling the pore structure of the mortar, and inhibits the migration of chloride ions in the mortar. At the later stage of corrosion, the dissolution of calcium carbonate and the conversion of C-S-H gel with a low calcium-silicon ratio into amorphous silica gel lead to the increase of mortar porosity and the acceleration of chloride ion migration in mortar. Carbonic acid water corrosion results in the decomposition of Friedel's salts and the decrease of the adsorption capacity of C-S-H gel for chloride ions. Reducing water-cement ratio can increase the corrosion resistance of mortar to carbonic acid water and reduce the migration rate of chloride ions..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2942 (2023)
Influence of Supplementary Cementitious Materials on Alkali-Silicate Reaction Characteristics of Seawater and Sea Sand Concrete
WANG Dehui, ZHANG Qizhi, GONG Qingnan, and LUO Surong
The characteristics of seawater sea sand concrete become a recent research issue, while the alkali-silica reaction (ASR) of seawater sea sand concrete is still unclear. To clarify the influence of supplementary cementitious materials on the alkali-silica reaction characteristics of seawater and sea sand concrete, the cThe characteristics of seawater sea sand concrete become a recent research issue, while the alkali-silica reaction (ASR) of seawater sea sand concrete is still unclear. To clarify the influence of supplementary cementitious materials on the alkali-silica reaction characteristics of seawater and sea sand concrete, the cement-metakaolin-fly ash-slag cementitious materials were designed by a simplex centroid design method. The effect of supplementary cementitious materials on the ASR products, pore structure, pore solution pH value, alkali ion content and expansion rate of seawater and sea sand concrete was investigated. The results show that the content of the amorphous product ASR-P1(K0.52Ca1.16Si4O8(OH)2.84·1.5H2O) and the crystalline product Na-shlykovite (NaCaSi4O8(OH)3·2.3H2O) in seawater and sea sand concrete are inversely proportional to the content of active SiO2 and Al2O3 in supplementary cementitious materials. Among the seawater and sea sand concretes with different cementitious materials, the pH value of paste prepared with 50% cement+25% metakaolin+25% fly ash and the contents of Na+, K+ and Ca2+ are the minimum values. As a result, the content of ASR-P1 and Na-shlykovite, the content of harmful pores and multi-harmful pores are the minimum values, as well as the porosity is the maximum value, thus resulting in the minimum expansion rate of the paste prepared with 25% metakaolin+25% fly ash +50% cement at 14 d and 28 d. This paper can provide a theoretical basis for the design of cementitious material composition of seawater and sea sand concrete, and improve the service life of seawater and sea sand concrete structure in marine engineering..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2955 (2023)
Preparation and Properties of Foam Insulation Material by Alkali-activate Recycled Powder-ground Granulated Blast Furnace Slag
YAO Tianshuai, TIAN Qing, ZHANG Miao, QI Shuai... and RUAN Mengyue|Show fewer author(s)
A foam insulation material was prepared by a wet foam mixing method with recycled powder and slag as main raw materials. The effects of alkali activator CaCl2·6H2O dosage and the preformed foam on the performance of foam insulation materials were investigated via testing the stabilization time of the foam, the conA foam insulation material was prepared by a wet foam mixing method with recycled powder and slag as main raw materials. The effects of alkali activator CaCl2·6H2O dosage and the preformed foam on the performance of foam insulation materials were investigated via testing the stabilization time of the foam, the condensing characteristics of the slurry, as well as the compressive strength, dry density, porosity and thermal conductivity of the specimens. The pore structure and reaction mechanism were analyzed by image analysis and X-ray diffraction. The results show that the compressive strength of the specimens firstly increases and then decreases with the increase of alkali exciter, and it reaches the maximum value at 5% of alkali activator, but the dosage of alkali activator has little effect on the porosity and dry density. The addition of CaCl2·6H2O significantly shortens the setting time of the slurry, thus favoring that the slurry and the prefabricated foam reach a better matching state, effectively refine the pores and improve the compressive strength and thermal inertia of the specimens. Different density grades of foam insulation materials can be prepared at different amounts of foam admixture. The pore size distribution becomes wider and the compressive strength and thermal conductivity decrease with the increase of foam admixture. The activity of both slag and recycled powder can be effectively stimulated, which can play a coordinating and complementary role to achieve the effect of synergistic utilization of solid waste..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2966 (2023)
Synthesis of Low Silicon Aluminum Ratio X Molecular Sieve from Potassium Feldspar and Its Ion Exchange Property
HAN Zhiyuan, GOU Minglei, CHEN Ziwan, DUAN Yonghua, and LIU Zhen
Low silicon aluminum ratio X molecular sieve (LSX) modified by lithium is widely used in the field of pressure swing adsorption (PSA) due to its high N2 adsorption capacity and nitrogen-to-oxygen separation ratio. However, the price of raw materials for the LSX synthesis increases, resulting in a higher production costLow silicon aluminum ratio X molecular sieve (LSX) modified by lithium is widely used in the field of pressure swing adsorption (PSA) due to its high N2 adsorption capacity and nitrogen-to-oxygen separation ratio. However, the price of raw materials for the LSX synthesis increases, resulting in a higher production cost. Potassium feldspar (i.e., KAlSi3O8) is rich in aluminum oxide and silicon oxide, and potassium can also be used as a structural guide agent for LSX as an ideal raw material that can greatly reduce the production cost for the LSX synthesis. LSX was synthesized by using seed crystal as a guiding agent with a potassium feldspar from Songxian, China as a raw material, which was firstly calcined and activated at a high temperature. The effects of silicon aluminum ratio (n(SiO2/n(Al2O3)), alkali silicon ratio (n(Na2O+K2O)/n(SiO2), water alkali ratio (n(H2O)/n(Na2O+K2O)), amount of seed guide agent (ωSDA), crystallization temperature (Tcry), and crystallization time (tcry) on the structure and properties of samples were investigated. The results show that when n(SiO2)/n(Al2O3)=2.1-2.2, n(Na2O+K2O)/n(SiO2)=2.0-2.2, n(H2O)/n(Na2O+K2O)= 35-40, ωSDA=3%-5%, Tcry=90-100 ℃, tcry=10-14 h, the obtained LSX molecular sieve has a high crystallinity, and a uniform morphology, and the exchange degree of Li+ can reach 98.7%, which obtain the properties for nitrogen and oxygen adsorption separation in industry..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2978 (2023)
K-Struvite Reinforced Magnesium Phosphate Cement for Solidification of Pb2+
PANG Bo, and LIU Runqing
Magnesium phosphate cement (MPC) can be used to solidify heavy metal ions in hazardous waste, and the introduction of heavy metal ions can significantly reduce the long-term mechanical properties of the solidified body. A method for strengthening MPC solidification of Pb2+ by adding K-struvite was proposed to solve theMagnesium phosphate cement (MPC) can be used to solidify heavy metal ions in hazardous waste, and the introduction of heavy metal ions can significantly reduce the long-term mechanical properties of the solidified body. A method for strengthening MPC solidification of Pb2+ by adding K-struvite was proposed to solve the problem of the mechanical property loss in the later stage of MPC solidification and ensure that the toxicity leaching meets the requirements. The results show that the leaching concentrations of K-struvite enhanced the MPC solidification of Pb2+ at 28 d and 180 d are 0.63 mg/L and 1.91 mg/L, the compressive strength at 180 d is similar to that of MPC uncured Pb2+ (without K-struvite), thus improving the mechanical properties of MPC and meeting the toxicity leaching requirements. The strengthening/solidification effect of K-struvite is mainly due to the improvement of the compactness and adsorption of the solidified body, improving the long-term solidification effect on Pb2+..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2986 (2023)
Properties and Applications of Low pH Value Cement-Based Material
LIU Jiangfeng, ZHANG Xiangyu, CHEN Liang, WANG Jv... and REN Zengzeng|Show fewer author(s)
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 2992 (2023)
Research Progress on Silicon-Terminated Diamond Semiconductors and Field-Effect Transistor Devices
LIU Jinlong, ZHAO Zichen, ZHAO Shangman, ZHU Xiaohua1... and LI Chengming|Show fewer author(s)
Diamond as a representative of ultra-wide bandgap semiconductor material has attracted recent attention. Although some progress is made in material preparation, device development and performance, semiconductor doping technology is not resolved so far. Hydrogen-terminated (C-H) diamond is widely used in microwave powerDiamond as a representative of ultra-wide bandgap semiconductor material has attracted recent attention. Although some progress is made in material preparation, device development and performance, semiconductor doping technology is not resolved so far. Hydrogen-terminated (C-H) diamond is widely used in microwave power devices due to its typical two-dimensional hole gas, but it has some problems such as poor stability and high interface state concentration. In contrast, silicon-terminated (C-Si) diamond that emerged in recent years has some advantages of lower interface state density, higher threshold voltage, carrier density, and stability rather than C-H diamond. C-Si diamond electronics exhibit the enhanced properties with high threshold voltages through an unclear mechanism. This review analyzed the structure and conduction mechanism of C-H diamond, the main problems that limit its development, represented the conduction mechanism, preparation method and corresponding interface structure of C-Si diamond, and discussed the performance level of C-Si diamond MOSFETs. In addition, the existing problems in the development of C-Si diamond were also discussed, and its future development was prospected..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 3005 (2023)
Application of Superabsorbent Polymer Hydrogel to Crack Self-Sealing of Cement-Based Materials
YANG Jin, DUAN Xiaopeng, QIU Jinyin, SU Ying, and HE Xingyang
Cement concrete is sensitive to cracking during service due to its brittleness and early susceptibility to shrinkage and deformation, further leading to the water seepage and leakage of concrete structure. The timely and effective repair of water leakage in cracked concrete has attracted recent attention in engineeringCement concrete is sensitive to cracking during service due to its brittleness and early susceptibility to shrinkage and deformation, further leading to the water seepage and leakage of concrete structure. The timely and effective repair of water leakage in cracked concrete has attracted recent attention in engineering. Superabsorbent polymer (SAP) hydrogel is a new type of self-sealing agent developed in recent years, which has the characteristics of rapid water absorption and significant volume expansion, and has a promising application potential in crack healing and sealing in humid environment. This review represented the basic design method of self-sealing cement-based materials based on hydrogel, discussed the working mechanism of SAP hydrogel as self-sealing agent and its effect on the anti-permeability, mechanics and durability recovery of concrete, and summarized the evaluation method of crack healing and sealing efficiency. In addition, the main challenges and future directions of hydrogel based crack self-sealing technology were also proposed..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 3015 (2023)
Rheological Properties and Their Regulation of Ultra-High Performance Concrete - A Short Review
LIU Yifan, WU Zemei, ZHANG Xuanhan, and SHI Caijun
Ultra-high performance concrete (UHPC) is a new cement-based composite material with ultra-high strength, high toughness, and excellent durability. Low water-to-binder ratio and large amount of fine particles in UHPC lead to some problems like high viscosity of fresh paste, fiber cluster issue, and difficulty in pumpinUltra-high performance concrete (UHPC) is a new cement-based composite material with ultra-high strength, high toughness, and excellent durability. Low water-to-binder ratio and large amount of fine particles in UHPC lead to some problems like high viscosity of fresh paste, fiber cluster issue, and difficulty in pumping, etc.. This is not beneficial to the homogeneity of concrete and fiber strengthening and toughening of UHPC, and restricts the in-situ placing and application of UHPC. This review represented the rheological properties of UHPC from aspects of rheological parameters and models. Based on the influence of water-to-binder ratio, chemical admixtures, mineral admixtures, fiber and aggregate characteristics on the rheological properties of UHPC, the techniques in regulating the rheological behavior of UHPC were analyzed. Such techniques include regulating water film thickness, regulating paste film thickness, reducing viscosity of interstitial fluid, adding viscosity modifier, and changing fiber characteristics. In addition, the rheology regulation mechanisms associated with these techniques were also discussed..
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 3025 (2023)
[in Chinese]
Journal of the Chinese Ceramic Society
- Publication Date: Jan. 18, 2024
- Vol. 51, Issue 11, 1 (2023)
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