Table of Content

Volume 44 Issue 8
15 August 2025

Previous Issue 　 Next Issue

Cement and Concrete

Collaborative Optimization of Strength and Accuracy of Binder Jetting 3D Printing Cementitious Materials

YANG Kuo, WANG Li, LI Zhijian

2025, 44(8):  2741-2751.  doi:10.16552/j.cnki.issn1001-1625.2025.0109

Asbtract ( 88 )   PDF (17214KB) ( 66 )  

References | Related Articles | Metrics

Binder jetting 3D printing features the advantages of high accuracy and support-free fabrication, which offers an effective method for intelligent construction in construction field. In order to solve the problem that the strength and accuracy of binder jetting 3D printing cementitious materials are difficult to cooperate, based on the magnesium phosphate cement based cementitious material system, effects of magnesium phosphorus ratio (M/P, molar ratio), water cement ratio (W/C) and layer thickness on compressive strength, bedding, printing accuracy and microstructure of specimens were studied in this paper. The results show that the size error of specimen decreases first and then increases with the increase of M/P, and increases with the increase of W/C. With the increase of layer thickness, the bedding phenomenon of specimen becomes more and more obvious. With the increase of M/P, the W/C corresponding to the highest strength decreases. With the increase of M/P, the internal structure of specimen becomes denser and the compressive strength of specimen increases. The dimensional accuracy and compressive strength of specimen are obviously anisotropic, and the dimensional error in the moving direction of the powder laying wheel is the largest. The compressive strength of specimen is the highest when loading along the stacked direction. The optimal M/P is 6, W/C is 0.14, the layer thickness is 100 μm, the optimal size error of the material is 2.65% of the design size of specimen, and the compressive strength is 39.1 MPa. The 3D printing material has a good application effect in the ancient building skin restoration project, and is of great significance to promote the application of binder jetting 3D printing technology in the construction field.

Effect of EVA Latex on Properties of Ultra-High Performance Engineered Cementitious Composites

HUANG Jie, SHUI Zhonghe, QI Xibo, LIU Jiabao, HUANG Zhoulong, HE Jing

2025, 44(8):  2752-2761.  doi:10.16552/j.cnki.issn1001-1625.2025.0001

Asbtract ( 99 )   PDF (16967KB) ( 94 )  

References | Related Articles | Metrics

The ultra-high performance engineered cementitious composites (UHPECC) were modified respectively by using stiff ethylene-vinyl acetate copolymer (EVA) powder with low vinyl acetate (VA) content, flexible EVA powder with high VA content and hydrophobic EVA powder based on vinyl laurate ester. The effects of three different types of EVA on the fluidity, compressive strength, flexural strength, tensile strength, ultimate tensile strain, bonding strength, interfacial impermeability, shrinkage characteristics, hydration degree, pore structure characteristics, and microscopic features of UHPECC were analyzed. The results show that the incorporation of all three types of EVA will reduce the fluidity and compressive strength of UHPECC, but will enhance the flexural strength, tensile strength, bonding strength, and interfacial impermeability of UHPECC. The stiff EVA group performs best in terms of flexural strength, tensile strength, and bonding strength. The flexible EVA group performs best in terms of fluidity, ultimate tensile strain, and shrinkage reduction. The hydrophobic EVA performs best in terms of interfacial impermeability. The incorporation of EVA will reduce the hydration degree of UHPECC, decrease the porosity, enhance the adhesion between the fibers and the matrix, and also increase the compactness at the interface defects between UHPECC and ordinary concrete, thereby improving the performance of UHPECC.

Preparation of Carbonation-Bonded Clinker from Low-Calcium High-Magnesium Limestone and Its Carbonation-Hardening Mechanism

ZHU Jianping, CAO Jianan, WANG Zuolin, LI Genshen, LIU Songhui, ZHENG Bo, FENG Chunhua

2025, 44(8):  2762-2770.  doi:10.16552/j.cnki.issn1001-1625.2025.0104

Asbtract ( 79 )   PDF (8774KB) ( 42 )  

References | Related Articles | Metrics

To tackle the issues of raw material constraints and carbon emissions in traditional Portland cement production, a new type of low-calcium and high-magnesium cement clinker was prepared using low-calcium and high-magnesium limestone (MgO mass fraction greater than 5%) and sandstone as raw materials. The main minerals of this clinker arebredigite (Ca₇MgSi₄O₁₆ , C₇MS₄), larnite (β-Ca₂SiO₄, β-C₂S),periclase (MgO) and merwinite (Ca₃MgSi₂O₈, C₃MS₂). By substituting raw materials, the consumption of limestone is reduced, and the high reactivity of magnesium minerals is utilized to realize the CO₂ mineralization curing technology for concrete. The research results show that this clinker system is formed at 1 220~1 260 ℃. After calcination, grinding and molding, and carbonation for 24 h under the conditions of a CO₂ purity of 99.9% (volume fraction) and a pressure of 0.3 MPa, the compressive strength can reach 90.2 MPa, and the carbon sequestration rate is as high as 9.22%. This technology offers a dual-emission-reduction solution of “source carbon reduction-process carbon sequestration” for the cement industry. It not only cuts down the limestone usage but also effectively sequesters CO₂, providing a new technological route for the green and low-carbon transformation of the cement industry.

Effect and Mechanism of Liquid Nano-CaCO₃ on Mortar Properties

SUN Jiuye, SUN Qian, WANG Dongmei, YANG Renhe, LI Jiaqi, RONG Hui, GUO Yibing, ZHANG Pengyu

2025, 44(8):  2771-2780.  doi:10.16552/j.cnki.issn1001-1625.2024.1623

Asbtract ( 82 )   PDF (14474KB) ( 40 )  

References | Related Articles | Metrics

The research of nanomaterials in cementitious materials has been increasing in recent years, among which nano-CaCO₃, as one of the most produced and used nanomaterials in many fields, has a promising application in cementitious materials.In order to investigate the effect of liquid nano-CaCO₃ (LNC) on mortar properties, different LNC content was selected to study its effects on mortar workability, mechanical properties, hydration behavior and microstructure.The results show that after adding LNC, the mortar fluidity shows a tendency of increasing and then decreasing with the increase of LNC content. Addition of LNC improves the flexural and compressive strength of the mortar, and the flexural and compressive strength at 3 d are increased by 14.29% and 32.51%, respectively, compared with the baseline group at 3.0% (mass fraction) LNC content. LNC improves the densification of cementitious materials through small size effect and nucleation effect, promotes the hydration reaction to proceed, and improves the pore structure.

Effects of MgO Expansive Agents on Properties and Microstructure of Mortar under Matched Curing Condition

BAI Min, LONG Yong, HUANG Wangming, HU Xiongwei, GUO Meng

2025, 44(8):  2781-2789.  doi:10.16552/j.cnki.issn1001-1625.2025.0068

Asbtract ( 59 )   PDF (15859KB) ( 36 )  

References | Related Articles | Metrics

To investigate the effects of MgO expansive agents (MEA) on core concrete of steel-concrete structures in closed and variable-temperature service environment, this study examined the influences of different active MEA on the macroscopic properties and microstructure of mortar under matched curing condition. The results indicate that the incorporation of MEA reduces both the slump flow and mechanical properties of mortar. In specific, high-activity MEA exhibit the greatest negative impact on the slump flow of mortar, while low-activity MEA notably affect the mechanical properties of mortar. Moreover, medium-activity MEA and high-activity MEA can generate a large quantity of Mg(OH)₂ crystals during the early and middle stages of hydration. These crystals exhibit effective shrinkage compensation by growing in situ or migrating to the surface of the cement hydration products, thereby reducing the cumulative pore volume, optimizing the pore structure, and enhancing the structural compactness. In contrast, the reaction rate and degree of low-activity MEA are slower than those of high-activity MEA. As a result, fewer Mg(OH)₂ crystals are generated, leading to a weaker compensation for the volume shrinkage of the mortar.

Effects of LDHs on Carbonation Resistance of Supersulfated Cement

WANG Jiawei, LI Chuanhai, ZHANG Chong, ZHANG Xiuzhi

2025, 44(8):  2790-2800.  doi:10.16552/j.cnki.issn1001-1625.2025.0187

Asbtract ( 62 )   PDF (14620KB) ( 33 )  

References | Related Articles | Metrics

To effectively enhance the carbonation resistance of supersulfated cement (SSC), 2% (mass fraction) of experimentally synthesized layered double hydroxides (LDHs) was added and compared with the same dosage of three admixtures: sodium aluminate (NaAlO₂), sodium hydroxide (NaOH), and sodium lactate (C₃H₅O₃Na). The effects of LDHs on the composition of hydration products, pore structure characteristics, and carbonation resistance of SSC concrete were investigated by means of mercury intrusion porosimetry (MIP), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric test (TG-DTG), and scanning electron microscopy (SEM). The results show that the 28 d compressive strength of SSC concrete with LDHs addition is the highest, reaching 40.6 MPa. The 28 d carbonation depth of SSC concrete is 22.7 mm, which is reduced to 14.6 mm with LDHs addition. The carbonation depths of SSC concrete with NaAlO₂, sodium lactate, and NaOH additions are 21.4, 17.2 and 24.5 mm, respectively. LDHs facilitate the formation of more hydration products in SSC concrete, reducing the total porosity of concrete by 6.28%. The addition of LDHs effectively improves the mechanical properties and carbonation resistance of SSC concrete. Sodium lactate and NaAlO₂ have a secondary effect compared to LDHs, while NaOH has no improvement effect. LDHs increase the degree of SSC concrete hydration and refine the pore structure. The dense concrete structure is conducive to the improvement of mechanical properties and carbonation resistance.

Printing Performance and Mechanical Properties of 3D Printed Concrete Mixed with Wind Turbine Blade Solid Waste

LI Wanrun, YAO Jianbing, ZHAO Wenhai, GAO Zhefeng, DU Yongfeng, ZHU Wenxuan

2025, 44(8):  2801-2813.  doi:10.16552/j.cnki.issn1001-1625.2025.0200

Asbtract ( 56 )   PDF (17115KB) ( 35 )  

References | Related Articles | Metrics

In order to study the effect of wind turbine blade solid waste (WTBW) on the performance of 3D printed concrete, this study mixed two kinds of WTBW into 3D printed concrete at different replacement ratios, and then the printing performance and mechanical properties of 3D printed concrete were tested. By analyzing the pore structure, the effect of WTBW on the performance of 3D printed concrete was explained from the microscopic point of view. The results show that the printing performance of concrete is the best when the WTBW replacement rate of powder type is less than 10% (mass fraction) and the WTBW replacement rate of fibrous villous type is less than 5% (mass fraction). The mechanical properties of the 3D printed concrete mixed with WTBW are obviously anisotropy. Compared with the control group, the 28 d compressive strength of the 3D printed concrete mixed with 10% powder WTBW increases by 7.28%, while the flexural strength and splitting tensile strength are not significantly improved, the mechanical properties of 3D printed concrete mixed with 5% fibrous villous type WTBW decrease, and the addition of WTBW can improve the significant anisotropy of concrete. The analysis of pore structure shows that powder WTBW plays a role of filling compaction in concrete and can effectively reduce the concrete porosity, while fibrous villous type WTBW increases the concrete porosity.

Experimental and Numerical Simulation Study on Shear Performance of 3D Printed Concrete Masonry

SUN Haohao, WANG Yifei, LIU Huawei, WU Yiwen, WANG Youqiang, LIU Chao

2025, 44(8):  2814-2822.  doi:10.16552/j.cnki.issn1001-1625.2024.1610

Asbtract ( 51 )   PDF (12391KB) ( 31 )  

References | Related Articles | Metrics

As an important support for the transformation of building industrialization, 3D printed concrete masonry (3DPCM) has insufficient research on the shear performance of structures and lacks structural design theory, which restricts the large-scale application of 3D printed concrete technology. To investigate the shear performance and influencing factors of 3DPCM, two types of 3DPCM with inclined ribbed cavity configurations were designed, and their failure modes and shear strength under shear load were analyzed. A proportional finite element model incorporating Cohesive elements was established to systematically explore the effects of key parameters, including material strength, cavity configurations, and interlayer bond strength on shear performance of 3DPCM. The results demonstrate that the 3DPCM of the two cavity configurations primarily exhibit double-shear failure, and an increase in the number of inclined ribs significantly enhances shear strength.Numerical simulation analysis shows that the interlayer bond strength has a significant impact on the shear performance and shows a positive correlation. The more evenly the inclined ribs are distributed in the cavity configurations and the larger the shear cross-section area is, the higher the shear strength will be. These research results can provide theoretical basis for the design of 3D printed concrete structures.

Effect of Fiber on Rheological and Mechanical Properties of 3DP-UHPC

ZHAO Yu, WANG Zhe, ZHU Lingli

2025, 44(8):  2823-2838.  doi:10.16552/j.cnki.issn1001-1625.2025.0083

Asbtract ( 48 )   PDF (31114KB) ( 30 )  

References | Related Articles | Metrics

Ultra-high performance concrete (UHPC) exhibits ultra-high strength and exceptional durability. However, the low water-to-binder ratio andfiber incorporation of UHPC lead to a significant reduction in flowability, which adversely affects both the extrudability and buildability of 3D printing of ultra-high performance concrete (3DP-UHPC) during the printing process. In order to prepare 3DP-UHPC suitable for high temperature environment, this paper explored the effects of different lengths and content of steel fiber and different content of polypropylene fiber on the rheological properties, early mechanical properties and mechanical properties after hardening of 3DP-UHPC, which provided a preliminary theoretical basis for subsequent high temperature testing. The results show that the length of steel fiber is the key factor affecting the extrudability, and the content of steel fiber and polypropylene fiber is the key factor affecting the buildability. With the increase of polypropylene fiber content, the wet embryo strength gradually decreases, which is the same as the development trend of static yield stress. The 3D printing process restricts the directional arrangement of steel fibers along the printing direction, so that the flexural strength of the 3D printed test block is higher than that of the traditional poured test block, and the pore distribution shows different characteristics.

Effect of Nano-TiO₂ Modified Foaming Agent on Properties of Foam Concrete

LI Jie, LI Shunkai, ZHAO Huan, ZENG Qinwei

2025, 44(8):  2839-2848.  doi:10.16552/j.cnki.issn1001-1625.2025.0060

Asbtract ( 48 )   PDF (22294KB) ( 29 )  

References | Related Articles | Metrics

To address the issue of poor stability of ordinary foaming agents, nano-TiO₂ was used to modify ordinary foaming agents in this paper. The effects of nano-TiO₂ content on foaming multiple, sedimentation distance and bleeding rate of foaming agent were investigated, while also effect of modified foam agent on the mechanical properties and microstructure of foam concrete was analyzed. The results indicate that nano-TiO₂ can effectively improve the performance of foaming agent. When with the optimum content of nano-TiO₂ is 0.15% (mass fraction, the same below), the foam multiple increases by 11.93%, the 1 h sedimentation distance and 1 h bleeding rate decrease by 54.29% and 12.21%, respectively, and the average thickness of the foam liquid film is 37.86 μm. The 3 d compressive strength of foam concrete prepared by adding 0.15% nano-TiO₂ is 1.637 MPa, which is 41.98% higher than that of the control group. Microscopic analysis reveals that nano-TiO₂ can obviously improve the porosity of foam concrete, and promote the formation of more calcium silicate hydrate (C-S-H) gels during the curing process of foam concrete slurry, so that the mechanical properties of foam concrete are significantly improved.

Influence of Vehicle-Bridge Coupled Vibration on Homogeneity of Widening Concrete

WANG Yuzheng, ZHOU Haotian, XIE Xin, GAO Xu, GAO Kui, CAO Hongyou

2025, 44(8):  2849-2855.  doi:10.16552/j.cnki.issn1001-1625.2025.0043

Asbtract ( 45 )   PDF (8303KB) ( 20 )  

References | Related Articles | Metrics

This study investigated the effects of the amplitude and frequency of vehicle-bridge coupled vibrations on the mechanical properties, homogeneity, and microstructure of widening concrete in bridge reconstruction and expansion projects. The layered mechanical properties and aggregate distribution of widening concrete before and after vibration were evaluated using compressive strength tests and computer vision technology. The changes in the microstructure of the concrete layers were analyzed using XRD and TG-DTG techniques. The results show that vibrations significantly exacerbate the layering phenomenon of widening concrete. Vibrations have a notable impact on the early strength of concrete, with the 3 d compressive strength reduced to 80% of the non-vibrated state. At 28 d, the compressive strength difference between the upper and lower layers further increases with the rise of amplitude and frequency. Higher amplitudes intensify the accumulation of coarse aggregates in the lower layer, reducing the spacing between aggregates and leading to a significant decline in overall homogeneity. Under high-frequency vibrations, hydration products such as calcium silicate hydrate (C-S-H) and ettringite tend to accumulate in the upper layer, while increased amplitude inhibits the hydration reaction in the lower layer. This results in an increased residual content of unhydrated tricalcium silicate (C₃S), reduced production of hydration products, and a distinct difference in the macro and micro structural characteristics between the upper and lower concrete layers.

Solid Waste and Eco-Materials

Leaching and Solidification/Stabilization of Heavy Metal Ions in Industrial Solid Wastes

LI Kangli, LU Xiaolei, ZHU Jiang, JIANG Congcong, ZHANG Lina, CHENG Xin

2025, 44(8):  2856-2872.  doi:10.16552/j.cnki.issn1001-1625.2025.0004

Asbtract ( 75 )   PDF (3202KB) ( 39 )  

References | Related Articles | Metrics

Heavy metal elements in industrial solid waste have the characteristics of various types, obvious regional characteristics, variable valence toxicity, various forms of migration and transformation, and unstable state. The leaching of heavy metal ions is a key problem restricting the resource utilization of industrial solid waste. In this paper, the leaching methods and leaching mechanisms of heavy metal ions in main industrial solid wastes at home and abroad are reviewed, and their advantages and disadvantages are compared. The solidification/stabilization methods and their mechanism of action commonly used in remediation of heavy metal pollution are mainly introduced. The main factors affecting the solidification/stabilization of heavy metal ions are reviewed. Finally, the detection and solidification/stabilization of heavy metals in industrial solid wastes are prospected. It is expected to provide reference for exploring the leaching behavior of heavy metal ions and the characteristics and mechanism of solidification/stabilization, and provide reference for realizing the efficient and safe resource utilization of industrial solid wastes.

Review on Performance Enhancements and Engineering Applications of Geopolymer Grouting Materials

ZHOU Yifan, ZHANG Weiye, CHEN Anjian, RAN Jinlin, WANG Dongxing

2025, 44(8):  2873-2890.  doi:10.16552/j.cnki.issn1001-1625.2025.0072

Asbtract ( 98 )   PDF (14628KB) ( 52 )  

References | Related Articles | Metrics

Geopolymer grouting material (GGM) is a new type of green, environmental-friendly, and low-carbon inorganic cementitious grouting material with a wide range of raw material sources. It shows many advantages, such as short setting time, good fluidity, high compressive strength, good durability, strong environmental adaptability. This article clarifies the effects of activators (alkaline and acidic) on the structures of geopolymer and explains the corresponding reaction mechanism models. The basic performances of GGM mainly including setting time, rheological properties, mechanical properties, and other properties are analyzed. The performance enhancement methods of GGM by using mathematical model optimization or fiber material reinforcements are summarized, and the engineering applications in different fields are also listed. Finally, the advantages and disadvantages of GGM are summarized. And the prospects for the research of GGM are put forward from the perspectives of different standards, less durability data, insufficient multi-scale simulation and fiber engineering practice.

Experimental Research on Impact Compression Performance of Cemented Coral Sand Containing Fine Particles

FAN Xiaochun, TIAN Chenlu, QIN Yue, ZHANG Biao

2025, 44(8):  2891-2899.  doi:10.16552/j.cnki.issn1001-1625.2025.0028

Asbtract ( 52 )   PDF (8721KB) ( 27 )  

References | Related Articles | Metrics

This article used a split Hopkinson pressure bar to conduct impact compression tests on cemented coral sand (CCS) at different strain rates, studying the impact compression performance of CCS containing fine particles and the influence of particle agglomeration on material mechanical properties. The experimental results show that, macroscopically, the dynamic compressive strength of CCS increases first and then decreases with the increase of fine particle content, and reaches its maximum value at 3% (mass fraction). As the degree of agglomeration deepens, the dynamic compressive strength of CCS gradually decreases. Microscopic analysis through mercury intrusion porosimetry reveals that the addition of a small amount of fine particles reduces the porosity and harmful pores of CCS, resulting in an increase in the macroscopic compressive strength of CCS. However, excessive fine particles are prone to agglomeration, leading to a decrease in the bonding strength of the interface transition zone, which can easily cause cracks and reduce material toughness and dynamic strength. By analyzing the dynamic growth factor of CCS and the relationship between specific absorption energy and strain rate, it is found that the dynamic growth factor has a significant strain rate effect. A small amount of coral sand particles can enhance the absorption energy of CCS, and there is an approximate linear relationship between specific absorption energy and strain rate.

Synthesis of Organic Soil by Geopolymer Solid Waste and Surgarcane Waste Residue Synergistic Dealkalization Red Mud

LIAO Xu, WANG Tao, JIANG Chuanfu, HE Yan, CUI Xuemin

2025, 44(8):  2900-2911.  doi:10.16552/j.cnki.issn1001-1625.2025.0103

Asbtract ( 59 )   PDF (13969KB) ( 39 )  

References | Related Articles | Metrics

In view of the serious pollution caused by the large-scale storage of red mud to the surrounding environment, soil formation of red mud is a feasible method to realize the large-scale consumption of red mud and reduce its environmental harm. In this study, red mud was dealkalized using dilute sulfuric acid, and then mixed with different proportion of geopolymer solid waste and sugarcane waste residue. The physical and chemical properties of the mixed matrix were analyzed to explore the synergistic effect of geopolymer solid waste and sugarcane waste residue on the soil formation process of red mud. The results show that after acid washing, the pH value of red mud decreases from 11.30 to 7.11, and the content of Na decreases from 10.711% to 0.750%, with the dealkaization rate is as high as 93%. After mixing with 30% (mass fraction) geopolymer solid waste, the pH value of red mud increases from 7.12 to 8.21, and the porosity and non-capillary porosity increases from 43.43% and 3.31% to 61.35% and 13.40%, respectively, both meeting the requirements of “Planting soil for greening” (CT/J 340—2016). After further mixing sugarcane waste residue with a mass ratio of 40%, the organic matter content of artificial soil increases significantly from 6.7 g/kg to 28.5 g/kg, the non-capillary porosity further increases to 20.39%, the available water content from 6.88% to 16.16%, the proportion of large aggregates increase, and ryegrass grow well.

Mechanical Properties of Quicklime-Activated Ground Blast Furnace Slag-Fly Ash Geopolymer-Stabilized Soil

HU Jianlin, LI Zhilin, ZHOU Yongxiang, LENG Faguang, DU Xiuli

2025, 44(8):  2912-2923.  doi:10.16552/j.cnki.issn1001-1625.2025.0116

Asbtract ( 51 )   PDF (22309KB) ( 35 )  

References | Related Articles | Metrics

This study investigated the effects of stabilizer mix ratio(quicklime, ground blast furnace slag and fly ash proportion), stabilizer content, and curing age on the unconfined compressive strength (UCS) and deformation modulus of quicklime-activated ground blast furnace slag-fly ash geopolymer-stabilized soil through UCS tests. The stabilization mechanism was revealed through SEM-EDS microstructural test. The results indicate that the UCS of geopolymer-stabilized soil initially increases and subsequently decreases with rising quicklime content. Increasing ground blast furnace slag content effectively enhances the UCS of stabilized soil. The early-stage UCS development rate of geopolymer-stabilized soil exceeds that of cement-stabilized soil, while its strength growth rate decreases during later curing periods, yet maintains higher values than cement-stabilized soil. Both deformation modulus and UCS demonstrate positive correlations with stabilizer content and curing age, exhibiting a favorable linear relationship. The hydration products (C-S-H, C-A-S-H, and C-A-H) generated by quicklime-activated geopolymer effectively bond soil particles and facilitate the formation of dense stabilized soil skeleton structures. These findings provide theoretical support for practical applications of quicklime-activated ground blast furnace slag-fly ash geopolymer stabilized soil in engineering projects.

Preparation and Thermal Insulation Performance of Coal Gangue-Fly Ash Fine Aggregate

WANG Xiaoxiao, ZHANG Haodong, CHAO Lumen, LIU Shuguang, CHEN Qi

2025, 44(8):  2924-2932.  doi:10.16552/j.cnki.issn1001-1625.2025.0005

Asbtract ( 69 )   PDF (11554KB) ( 40 )  

References | Related Articles | Metrics

The recycling of coal gangue and fly ash can reduce the negative impact on ecological environment. In this study, coal gangue and fly ash were used as raw materials. The preheating temperature, preheating time, calcination temperature and calcination time were tested by the Taguchi method. And the crushing index and thermal conductivity coefficient were used as evaluation indexes to optimize the preparation process of fine aggregate. The insulation mechanism of fine aggregates was analyzed in terms of phase composition, micromorphology and pore structure using X-ray diffraction, scanning electron microscopy and mercury intrusion porosimetry. The research findings indicate that the raw materials can be processed under conditions of a preheating temperature of 400 ℃ for 25 min, followed by a calcination temperature of 1 250 ℃ for 25 min, to produce coal gangue-fly ash fine aggregates with a crushing index of 29.1% and a thermal conductivity of 0.138 W/(m·K). Simultaneously, an increase in the calcination temperature contributes to an enhancement in the content of mullite crystals and the compactness of pores. Furthermore, high temperatures can reconstruct the pore structure of porous aggregates, increasing the number of pores with diameters greater than 10 000 nm, which contributes to improving both the strength and thermal insulation performance of the fine aggregates.

Mix Ratio Optimization and Performance Study of Fly Ash Based Grouting Water Blocking Materials under Dynamic Water Conditions

ZHENG Yingwu, MA Hongjian, HOU Ning, SHEN Hengming, HUANG Feng

2025, 44(8):  2933-2943.  doi:10.16552/j.cnki.issn1001-1625.2025.0150

Asbtract ( 71 )   PDF (8316KB) ( 32 )  

References | Related Articles | Metrics

To address the drawbacks of traditional dynamic water grouting materials, such as long gelation time, low dynamic water retention rate, high cost, as well as the problem of ineffective utilization of industrial solid waste fly ash in power plants under the “coal electricity integration” business model. Based on the demand for water blocking treatment in coal mine water rich sand layers, orthogonal experiments were conducted on cement-fly ash-water glass grouting materials using slurry water-cement ratio, fly ash content, bentonite content, and retarder content as experimental factors, and slurry apparent viscosity, water separation rate, gelation time, and dynamic water retention rate as indicators. The optimal slurry ratio that meets the engineering requirements was selected through range analysis and comprehensive balance analysis. Based on the optimal slurry ratio, a simulation experiment was conducted on the water blocking effect of dynamic water grouting materials. The effects of grouting pressure and grouting volume on the water blocking performance and diffusion ability of slurry were analyzed, and the water blocking effect of optimal slurry under dynamic water conditions was verified. The results show that the optimal slurry ratio is water-cement ratio of 1.2, fly ash content of 30% (mass fraction), bentonite content of 6% (mass fraction), retarder content of 1.75% (mass fraction), and water glass content of 5% (mass fraction). The effective diffusion distance of optimal slurry shows a positive correlation with grouting volume. As the grouting volume increases, the diffusion capacity of slurry enhances while slurry loss decreases. When the grouting pressure is not less than 40 kPa and the grouting volume is not less than 800 mL, the average water blocking rate of grouting materials under optimal slurry ratio exceeds 90%, demonstrating excellent water blocking effect.

Hardened Body Preparation and Performance Adjustment of High Content Phosphogypsum Cementitious Materials

LI Yisheng, LYU Wei, WU Chiqiu, YU Zhengkang, HE Jing, SHUI Zhonghe

2025, 44(8):  2944-2954.  doi:10.16552/j.cnki.issn1001-1625.2025.0049

Asbtract ( 66 )   PDF (10704KB) ( 41 )  

References | Related Articles | Metrics

In order to prepare high-strength and high content phosphogypsum cementitious materials, the effects of shaping pressure, calcium-silicon-aluminum ratio and alkali activator content on the properties of high content phosphogypsum cementitious materials hardened body were studied. Based on the Box-Behnken design in the response surface method, the interaction mechanism of each influencing factor on the compressive strength was analyzed. In addition, the microstructure of the hardened body was analyzed by X-ray diffraction and scanning electron microscopy. The results show that the long-term performance of the hardened body of phosphogypsum cementitious materials increases first and then decreases with the increase of shaping pressure, calcium-silicon-aluminum ratio and alkali activator content. Through the response surface model analysis, the interaction effect of the influencing factors on the strength development from strong to weak is the shaping pressure, calcium-silicon-aluminum ratio, alkali activator content. When the shaping pressure is 60 MPa, the calcium-silicon-aluminum ratio is 1.1(molar ratio), and the alkali activator content is 0.5‰ (mass fraction), the hardened body of high content phosphogypsum cementitious material with compressive strength exceeding 65 MPa can be prepared. The well-crystallized needle-like ettringite fills the gap between the phosphogypsum particles, and the calcium silicate hydrate (C-S-H) gel wraps the cemented phosphogypsum particles and ettringite crystals to form a dense structure.

Preparation of High Belite Sulphoaluminate Cement Clinker from Industrial Solid Waste and Microscopic Mechanism of Mineral Formation

YAN Wanying, WANG Dongxing, NIE Liwen

2025, 44(8):  2955-2964.  doi:10.16552/j.cnki.issn1001-1625.2025.0102

Asbtract ( 81 )   PDF (6433KB) ( 46 )  

References | Related Articles | Metrics

This study utilized phosphogypsum, red mud, aluminum ash, carbide slag, and coal gangue as raw materials to prepare high belite sulphoaluminate cement (HBSAC) from solid waste. Through thermogravimetric analysis, XRD, SEM and compressive strength test, the calcination process of HBSAC clinker was studied, the reaction process and formation mechanism of clinker minerals were analyzed, and the mechanical properties of HBSAC were explored. The results demonstrate that the optimal calcination system involves heating at 10 ℃/min to 1 300 ℃ and keep the temperature for 45 min. Under this calcination process, the strength performance of HBSAC is excellent, and the compressive strength at 1, 3, 7 and 28 d can reach 29.1, 40.1, 42.1 and 54.0 MPa, respectively. The strength properties of HBSAC can be reguated by controlling the development of mineral phases. When the calcination temperature is below 1 225 ℃, residual non-hydraulic hardening transitional minerals exist. Incomplete crystallization of tetracalcium trialuminate sulfate (C₄A₃$\bar{S} $) and dicalcium silicate (C₂S) degrade the compressive strength of HBSAC. When the calcination temperature is 1 225~1 350 ℃, ferrite phase (C₄AF) formation enhances liquid phase content, facilitates ion diffusion and promotes the formation of target minerals C₄A₃$\bar{S} $ and C₂S.

Ceramics

Discrete Element Simulation of Random Packing of Flake Particles in Boron Nitride Ceramic Green Body

YE Wenkang, QI Zheng, YE Yanli, HE Zijun, MEI Shuxia, XIE Junlin

2025, 44(8):  2965-2976.  doi:10.16552/j.cnki.issn1001-1625.2025.0040

Asbtract ( 54 )   PDF (13201KB) ( 41 )  

References | Related Articles | Metrics

Hexagonal boron nitride (h-BN) ceramics have important application value in aerospace and other fields due to their layered structure and excellent directional thermal conductivity. In this study, the effects of particle size, aspect ratio and external axial pressure on the packing structure of flake particles were analyzed by discrete element method (DEM). The results show that large size particles, large aspect ratio and external axial pressure can promote the orderly arrangement of particles and optimize the orientation. The external axial pressure and large particles contribute to the contact between particles, increase the coordination number and reduce the porosity, while increasing the aspect ratio will increase the porosity. The thickness of the particles increases from 5 μm to 20 μm, the overall packing porosity decreases from 0.65 to 0.57, the average coordination number increases from 2.56 to 4.43, and the average orientation angle decreases from 45.30° to 10.70°. When the aspect ratio increases from 20 to 100, the porosity increases from 0.65 to 0.76, and the average particle orientation angle changes from 45.30° to 12.74°. When the external axial pressure is 7 MPa, the overall packing porosity decreases by 0.15~0.16, the average coordination number increases by 1.57~2.40, and the average particle orientation angle decreases by 7.19°~12.03°. This study provides a theoretical reference for the optimization of the packing process of h-BN ceramic hot pressing sintering.

Preparation and Properties of Blue Zirconia Ceramics Based on SLA Photopolymerization

ZHU Jiahao, CHEN Shenggui, LIANG Jiahua, QIN Jiata, LI Nan, ZHOU Zhukun

2025, 44(8):  2977-2987.  doi:10.16552/j.cnki.issn1001-1625.2025.0050

Asbtract ( 58 )   PDF (21245KB) ( 51 )  

References | Related Articles | Metrics

Colored zirconia ceramics can be widely used in high-tech fields such as mobile phone backplanes and high-end decorative materials due to their adjustable color, good mechanical processing and strong stability. In this study, three blue zirconia ceramic pastes with different Co₃O₄ content and a total solid content of 55% (volume fraction) were prepared and successfully used for stereolithography (SLA) photopolymerization printing. The results show that the addition of a small amount of Co₃O₄ slightly improves the flexural strength of the ceramic samples compared with the uncolored samples. The average grain size after sintering increases with the increase of Co₃O₄ content, and the monoclinic phase structure in the ceramic samples gradually increases. And the chromogenic mechanism of the blue zirconia ceramic samples is investigated, with the increase of Co₃O₄ content, the reflectance of the ceramic samples in the blua light range (435~490 nm) appeares to be significantly decreased. When the Co₃O₄ content is 1.0% (mass fraction), the mechanical and optical properties of the obtained samples are the best. The flexural strength and Vickers hardness of the ceramic samples are significantly better than those obtain in previous studies. This study has realized the use of blue ceramic materials to print monolithic movable parts, and this parts achieve high precision and superior performance, providing the possibility of printing high-strength structures in the field of high-end decorative materials.

Effect of Sintering Schedule on Performance of Ceramic Bond Diamond Grinding Wheel

RUAN Jiahao, ZHANG Lei, LI Yujia

2025, 44(8):  2988-2995.  doi:10.16552/j.cnki.issn1001-1625.2025.0111

Asbtract ( 83 )   PDF (13577KB) ( 32 )  

References | Related Articles | Metrics

To meet the performance requirements of ceramic bond diamond grinding wheels for precision machining, this study investigated the effect of sintering schedule (sintering temperature and holding time) on the grinding wheel properties by altering these parameters. Grinding wheel samples were characterized using scanning electron microscope, X-ray diffractometer, Rockwell hardness testing, Archimedes' drainage method, and three-point bending tests to determine the optimal sintering temperature and holding time. The results show that within the experimental parameter ranges of sintering temperature (670~750 ℃) and holding time (60~180 min), the phase composition of the grinding wheel samples remains unchanged, consisting of diamond and Li_xAl_xSi_3-xO₆. The sintering temperature has a more significant effect on the grinding wheel performance than the holding time. The optimal sintering temperature is 710 ℃, at which the grinding wheel sample exhibits a bending strength of 106.92 MPa, Rockwell hardness of 90.6 HRB, volume shrinkage rate of 10.48%, and porosity of 9.36%. The optimal holding time range is 90~150 min, during which the porosity and volume shrinkage rate of the grinding wheel samples remain at approximately 10%, the bending strength is around 107 MPa, and the Rockwell hardness is approximately 90.5 HRB.

Effect of Heating Regime on Performance of Iron Tailings-Based Ceramsite

CHAI Qian, CHEN Liulin, ZHANG Tiantian, CHENG Fengmei, WANG Yongxin, XIAO Wenxuan, ZHANG Hui, HE Panyang

2025, 44(8):  2996-3004.  doi:10.16552/j.cnki.issn1001-1625.2025.0322

Asbtract ( 49 )   PDF (7541KB) ( 22 )  

References | Related Articles | Metrics

Utilizing large-stockpiled iron tailings as the primary raw material for ceramsite production effectively mitigates environmental pollution issues and advances sustainable resource development. To optimize the heating regime for energy conservation, emission reduction, cost efficiency, and performance enhancement, this study established a preheating temperature of 700 ℃ and a maximum sintering temperature of 1 125 ℃ based on thermogravimetric analysis of the raw material's thermodynamic behavior. A two-stage heating process for sintering was employed, and the impact of varying heating regimes on the performance of iron tailings-based ceramsite was systematically investigated. The results demonstrate that the optimal comprehensive energy efficiency is achieved under the rapid heating regime of 20 ℃/min to 700 ℃ followed by the slow heating regime of 5 ℃/min to 1 125 ℃ by balancing the performance and sintering energy consumption of iron tailings-based ceramsite. Under this condition, the single-particle compressive strength is 11.50 MPa, the apparent porosity is 20.77%, the apparent density is 1 903 kg/m³, the specific strength is 6 040 N·m/kg, the 1 h water absorption rate is 9.81%, and the 24 h water absorption rate is 10.93%. During medium-to-low temperature sintering stage, rapid heating accelerates gas evolution, and enhances apparent porosity while preserving structural integrity and mechanical strength. Conversely, reducing the heating rate in the high-temperature sintering range can promote the formation of liquid phase and solid-phase reactions, which benefits the improvement of strength. XRD analysis reveals that high-temperature sintering of the raw material generates new mineral phases including augite, sanidine, and rankinite. Notably, reducing the heating rate during the high-temperature stage significantly enhances the content of these mineral phases.

Preparation of Low-Expansion and Heat-Resistant Purple Clay Pottery Using Hainan Zijin Clay

HE Mengzhen, LI Yueming, ZHANG Xiaona, WANG Yuhui, LI Kai, HUANG Yuanyuan

2025, 44(8):  3005-3013.  doi:10.16552/j.cnki.issn1001-1625.2025.0078

Asbtract ( 57 )   PDF (18797KB) ( 33 )  

References | Related Articles | Metrics

In this study, the Hainan Zijin clay, spodumene, lithium white stone, burnt talc and kaolin were used as raw materials. The formula composition was optimized by changing the content of burnt talc and kaolin, and the coefficient of thermal expansion of sample was adjusted to prepare low-expansion and heat-resistant purple clay pottery. The change of thermal shock resistance was characterized by coefficient of thermal expansion and flexural strength. The results show that when the content of Zijin clay is 32.8% (mass fraction), the content of spodumene is 32.8% (mass fraction), the content of lithium white stone is 9.4% (mass fraction), the content of burnt talc is 10.0% (mass fraction), and the content of kaolin is 15.0% (mass fraction), the coefficient of thermal expansion of purple clay pottery sample prepared by raw material ball milling for 9 h and holding at 1 150 ℃ for 60 min is the lowest (1.32×10^-6 ℃^-1), the water absorption rate is 0.25%, and the flexural strength is 83.89 MPa.

Preparation and Characterization of Celadon Glazes Derived from Porcelain Waste Combined with Oyster Shell

LAN Lin, QIU Boxin, WU Yien, LIN Shaomin

2025, 44(8):  3014-3021.  doi:10.16552/j.cnki.issn1001-1625.2024.1418

Asbtract ( 39 )   PDF (9164KB) ( 22 )  

References | Related Articles | Metrics

Porcelain waste and oyster shell are major solid waste pollutants in China's coastal areas. How to achieve high-value utilization of porcelain waste and oyster shell is an urgent problem to be solved. In this study, the compositional characteristics of different types of porcelain waste and oyster shell were analyzed. Then based on single-component daily-used porcelain waste, the effects of the addition of multi-component porcelain waste and reducing atmosphere on the melting characteristics, optical properties, and hardness of glaze were explored. The phase, morphology, and high-temperature behavior of glaze were analyzed by XRD, SEM, EDS, and thermal analysis techniques. The results show that primary enstatite in magnesia porcelain waste acts as a flux, which is beneficial to reduce the melting temperature of glaze. The sphere temperature, hemisphere temperature, and flow temperature of glazes decrease from 1 248, 1 255 and 1 268 ℃ to 1 213, 1 222 and 1 231 ℃, respectively. Bone china porcelain waste introduces P₂O₅, which exerts a “network-mending” effect within the silicate network, and broadens the temperature range for glaze formation. Moreover, the addition of reducing agent leads to the formation of blue Fe²⁺, so that the glaze color changes from yellow to blue-green. At the same time, as a glass network modifier, Fe²⁺ reduces the viscosity of the glaze melt, promotes the diffusion mass transfer of glaze and the crystallization of anorthite, resulting in a decrease in the gloss and an increase in the hardness of glaze surface.

Glass

Influences of Composition and Light Source Wavelength on Stress-Optic Coefficient of Alkali-Aluminosilicate Glass

TIAN Haonan, ZHOU Zeyun, ZHANG Xingzhi, ZHAO Zhiyong

2025, 44(8):  3022-3030.  doi:10.16552/j.cnki.issn1001-1625.2025.0126

Asbtract ( 55 )   PDF (3941KB) ( 40 )  

References | Related Articles | Metrics

Alkali-aluminosilicate glass (R₂O-RO-Al₂O₃-SiO₂) has emerged as an important new type of glass, finding applications in screen protection, high-speed rail, aviation and photovoltaic. This study investigated stress-optical coefficient of alkali-aluminosilicate glass by designing an optical path system and constructing a measurement device based on the tensile measurement method. Glass fibers with diameters of 0.70 mm to 0.80 mm were used as samples. The influences of glass composition (R₂O, RO, Al₂O₃, SiO₂) and light source wavelengths (640, 587, 518 nm) on stress-optical coefficient were investigated. The main findings indicate that the stress-optical coefficient is determined by composition of each oxide and stress-optical coefficient factors, exhibiting additivity. The stress-optical coefficient decreases nonlinearly with increasing light source wavelength. Additionally, the stress-optical coefficient of the glass is proportional to the cube of the refractive index n³ and Poisson ratio μ, while being inversely proportional to the elastic modulus E. The oxide stress-optical coefficient factors obtained in this study provide technical support and predictive guidance for the design of stress-optical coefficients in alkali-aluminosilicate glass.

Effects of Composition and Particle Size on Vitrification, Structures and Properties of Plasma Melting Al₂O₃-CaO Binary Microspheres

ZHOU Yangcheng, WANG Xiang, WEN Bin, ZHANG Jihong, XIE Jun, HAN Jianjun

2025, 44(8):  3031-3041.  doi:10.16552/j.cnki.issn1001-1625.2025.0190

Asbtract ( 72 )   PDF (26423KB) ( 37 )  

References | Related Articles | Metrics

As a new type of micron-scale specialty material, glass and ceramic microspheres have been widely studied and applied in recent years. In this research, a series of Al₂O₃-CaCO₃ initial powders with different compositions and particle sizes were prepared by spray granulation equipment, and a series of Al₂O₃-CaO binary glass/ceramic transparent microspheres were successfully prepared by plasma melting method. The results show that after Al₂O₃-CaO system spheroidization, when the Al₂O₃ content is more than 50% (mole fraction, the same below), the microspheres are mainly in ceramic state, and the main crystal phases are Ca₃Al₁₀O₁₈, CaAl₂O₄ and CaAl₄O₇. When the content of Al₂O₃ is 50 %, the mixture of glass and ceramic microspheres can be formed, and the main crystal phase is CaAl₂O₄. When the Al₂O₃ content is 34%, the microspheres are mainly glass state, accompanied by a small amount of Ca₃Al₂O₆ and CaAl₂O₄ crystal phases. As the particle size of the microspheres decreases, the content of the glass phase also increases. The hardness and elastic modulus of the microspheres are closely related to the composition and microstructure. The maximum hardness is 10.45 GPa, and the elastic modulus is 114.1 GPa, which decreases after the formation of glass microspheres. ²⁷Al NMR analysis results show that with the increase of alumina content, the coordination state of aluminum in the microspheres changes from four-coordinated to five-coordinated and six-coordinated, and the particle size has little effect on it.

Refractory Materials

Influence of Titanium Dioxide on Properties of Zinc Aluminate Refractory Ceramics

LIU Qi, HUANG Shimou, HAO Jianying, CUI Buzhe, ZHU Zhenguo, BAI Shuo

2025, 44(8):  3042-3048.  doi:10.16552/j.cnki.issn1001-1625.2025.0053

Asbtract ( 61 )   PDF (6895KB) ( 24 )  

References | Related Articles | Metrics

In order to develop zinc aluminate (ZnAl₂O₄) refractory ceramics with low thermal conductivity and high mechanical properties, titanium dioxide (TiO₂) was added to modify its properties. ZnAl₂O₄ refractory ceramics was prepared by solid-phase reaction sintering method using alumina and zinc oxide as aluminum and zinc sources, and magnesium oxide as sintering aid. The effect of TiO₂ content on the properties of ZnAl₂O₄ refractory ceramics was investigated, and the modification mechanism was revealed from the changes of phase and micromorphology. The results indicate that the properties of ZnAl₂O₄ ceramics are improved with the increase of TiO₂ content. When the TiO₂ content is 11% (mass fraction), the ZnAl₂O₄ ceramics obtained by sintering at 1 500 ℃ have the best performance. Their apparent porosity is 3.5%, bulk density is 4.21 g/cm³, linear shrinkage rate is 28.53%, the maximum flexural strength is 202.3 MPa, and the thermal conductivity is 10.003 W/(m·K). The addition of TiO₂ can promote the growth of zinc aluminate grain and generate solid solution Zn_1.5Ti_0.25Al₄O₈, which makes the zinc aluminate grain more perfect and the structure more dense. At the same time, the addition of TiO₂ can also reduce the sintering temperature of zinc aluminate ceramics, which meets the requirements of energy saving and environmental protection.

Preparation and Fireproof Performance of Geopolymer Lightweight Fire Resistant Coating

ZHU Yiyang, GENG Haining, LI Zonggang, MA Haosen, LUO Yang, CHEN Wei, LI Qiu

2025, 44(8):  3049-3060.  doi:10.16552/j.cnki.issn1001-1625.2024.1621

Asbtract ( 74 )   PDF (20302KB) ( 114 )  

References | Related Articles | Metrics

Steel structures are widely used in modern architecture, but under high-temperature fire environment, the mechanical properties of steel structure will be rapidly lost, which may cause severe casualties and properties losses, so it is vital to protect steel structures from fire. In this study, metakaolin-based geopolymer lightweight fire resistant coating (referred to as fire resistant coating) was prepared by using metakaolin and slag as raw materials, 1.5-mode potassium water glass as alkaline activator, hydrogen peroxide solution as foaming agent, MnO₂ as catalyst, and sodium oleate as form stabilization agent. The effect of content of hydrogen peroxide solution on the dry density, thermal conductivity, porosity, compressive strength, and adhesive strength of fire resistant coatings was investigated, and the fire resistance limit test was performed to examine the practical fireproof performance of the fire resistant coating. Micro-CT was employed to perform a comparative analysis of the pore structure in specimens before and after fire resistance limit test. And XRD, TG-DSC, and SEM-EDX were employed to characterize the phase transformation and microstructure evolution of the samples during high-temperature fire, elucidating the fire resistance mechanism. The results indicate that when the content of hydrogen peroxide solution is 1.5% (mass fraction), the dry density, compressive strength, and adhesive strength of sample are all better than the requirements of “Fire resistive coating for steel structure” (GB 14907—2018) and the thermal conductivity is as low as 0.132 W/(m·K).When the coating thickness of the fire resistant coating is 15 mm and the content of hydrogen peroxide solution is 1.5% (mass fraction), the back temperature of sample steel plate is 162 ℃ after 120 min fire resistance test under 1 300 ℃ flame, which has excellent fireproof resistance. During the fire resistance limit test, the ceramization transformation on the surface of the fire retardant coating, which reduces the damage of the flame to the internal pore structure and contributes to the fireproof performance of the fire retardant coating. The fire resistant coating undergoes ceramization transformation at high-temperature to form multiphase heat-resistance ceramics, which improves the fire resistance of the fire resistant coating.

Functional Materials

Effect of 3-Pyridyl Thiourea Additive on Performance of Perovskite Solar Cells

LIU You, LU Runlin, HU Jiale, CHEN Junming

2025, 44(8):  3061-3068.  doi:10.16552/j.cnki.issn1001-1625.2025.0506

Asbtract ( 63 )   PDF (6183KB) ( 22 )  

References | Related Articles | Metrics

Perovskite solar cells are of great interest due to their excellent optoelectronic properties, yet their commercialization is restricted by insufficient power conversion efficiency (PCE) and stability. This study introduced 3-pyridylthiourea (3-PTU) as an additive in the fabrication of planar-structured perovskite solar cells to evaluate its impact on the quality of perovskite films and the photovoltaic performance of cells. Perovskite films were fabricated via a one-step spin-coating method. A suite of characterization techniques, including X-ray diffraction, scanning electron microscopy, ultraviolet-visible absorption spectroscopy, photoluminescence spectroscopy, and current density-voltage curve measurements, were employed to analyze the films and devices. The results indicate that the addition of 3-PTU notably enhances the crystallinity of the perovskite films, leading to enlarged grain size, improved hydrophobicity, and a reduction in non-radiative recombination defect states. Consequently, devices treated with 3-PTU demonstrate an increase in PCE from 22.46% to 23.75%, a rise in open-circuit voltage from 1.17 V to 1.21 V, and negligible hysteresis effects.

CMC-Modified Two-Dimensional Montmorillonite Membrane for Simulating Multivariate Ions Separation in Salt-Lake Brine

WANG Huatao, MIAO Yanhui, ZHAO Yunliang, KUANG Bowen, JIANG Xiongrui, GAO Renbo, ZHANG Tingting

2025, 44(8):  3069-3078.  doi:10.16552/j.cnki.issn1001-1625.2025.0093

Asbtract ( 40 )   PDF (9046KB) ( 23 )  

References | Related Articles | Metrics

With the rapid development of new energy industry in China, the technology of lithium extraction from primary salt-lake brine is particularly important, but the coexistence of lithium ions with potassium ions and magnesium ions increases the difficulty of separation. Two-dimensional nanochannel membranes show good prospects in ion separation due to nanoscale channel structure, but the high instability of channels affects the separation performance and reduce efficiency. In this study, two-dimensional montmorillonite channel membranes were constructed by modifying montmorillonite nanosheets with sodium carboxymethyl cellulose (CMC). The results show that the interaction between CMC and the edge of nanosheets facilitates the assembly of small nanosheets into large nanosheets, which enhances the negative electronegativity of nanosheets surface, and facilitates the transport of cations. Meanwhile, the hydrophilicity of membranes are regulated and the channel expansion is limited to realize the control of channel height by adding CMC. In the salt-lake brine multi-ion separation test, the membranes show excellent ion separation performance, with a separation selectivity of 15.10 for Li⁺/Mg²⁺ and up to 60.30 for K⁺/Mg²⁺. In the monovalent ion separation test, the membranes show certain K⁺/Li⁺ separation selectivity, which provides technical support for the application of high-performance two-dimensional montmorillonite membranes in lithium extraction from primary salt-lake brine.

Surface Modification of Titanium Dioxide on Cellulose Acetate/Hydroxyapatite Composite Membrane

LIU Jiaxin, LIU Li, WANG Shuang, ZHANG Shisheng, ZHU Qingxia

2025, 44(8):  3079-3087.  doi:10.16552/j.cnki.issn1001-1625.2025.0018

Asbtract ( 57 )   PDF (13628KB) ( 19 )  

References | Related Articles | Metrics

The modification of organic membranes with inorganic nanoparticles has always been a research hotspot. Polydopamine (PDA) can be used to increase the adhesion of titanium dioxide (TiO₂) on cellulose acetate/hydroxyapatite (CA/HA) composite membranes. In this study, the effects of PDA polymerization time and TiO₂ concentration on membrane structure, hydrophilicity, permeability, mechanical properties, as well as the pollution resistance and photocatalytic performance of composite membrane were investigated. The research results indicate that the introduction of PDA and TiO₂ improves the hydrophilicity of the membrane surface, and significantly increases membrane retention. With the increase of PDA polymerization time, the tensile strength of composite membranes increases first and then decreases. TiO₂ endows the membrane with photocatalytic performance, improves membrane regeneration performance of organic membranes. The composite membrane exhibites high flux recovery rate and excellent pollution resistance with the PDA polymerization time of 6 h and TiO₂ concentration of 0.1% (mass fraction).

High-Performance BaTiO₃/Graphene Humidity Sensor and Its Application in Human Respiratory Monitoring

ZHU Congcong, HUANG Shimou, WANG Xujie, LIU Shengsheng, CUI Sheng

2025, 44(8):  3088-3095.  doi:10.16552/j.cnki.issn1001-1625.2025.0273

Asbtract ( 43 )   PDF (11383KB) ( 16 )  

References | Related Articles | Metrics

Respiratory diseases can be monitored early and warned through multiple respiratory parameters. As the core component of respiratory state monitoring, humidity sensors have inherent defects such as high cost, rigid substrate and low portability. This paper proposed a new wearable humidity sensor based on BaTiO₃ and laser induced graphene (LIG) interdigital electrodes.The efficient “one-step” process of LIG interdigital electrodes was achieved through laser direct writing technology. The results show that LIG presents a unique honeycomb-like three-dimensional porous structure. This structure effectively increases the specific surface area of the humidity-sensitive layer and provides more adsorption sites for water molecules.The BaTiO₃/LIG sensor has excellent capacitive response/recovery performance, cyclic stability, and mechanical properties in the relative humidity range of 11%~97%. When applied to human respiratory monitoring, the device can sense and record respiratory signals in real time. By analyzing the peak shape, intensity, half-peak width, fluctuation and respiratory cycle time of the capacitance curve, different respiratory organs, respiratory frequencies and respiratory distances can be identified, which is of great value for intelligent medical diagnosis.

Effect of DEIPA Synergistic Pressure on Performance of Dry-Prepared Ca(OH)₂ and Process Parameter Study

ZHANG Chaoyang, XUE Jianxun, GAO Peng, MEI Wenzheng, WU Xiaojian, ZHOU Mingkai

2025, 44(8):  3096-3104.  doi:10.16552/j.cnki.issn1001-1625.2025.0096

Asbtract ( 58 )   PDF (6477KB) ( 16 )  

References | Related Articles | Metrics

High specific surface area Ca(OH)₂ has been widely used in the field of flue gas desulfurization due to its low cost, high desulfurization performance and secondary utilization of desulfurization products. However, the preparation process of high specific surface area Ca(OH)₂ in China is not yet mature, and most of high specific surface area Ca(OH)₂ rely on imports. In this study, industrial grade lime was used as raw material, and high temperature autoclave was used as digestion device to optimize the digestion process parameters in the process of dry-prepared Ca(OH)₂. The effects of modifier type and dosage, pressure and other conditions on the properties of Ca(OH)₂ were investigated. The samples were characterized by specific surface area and porosity analyzer, particle size analyzer, XRD and SEM. The results show that under the conditions of water cement mass ratio of 0.45, raw material particle size less than 1.250 mm, stirring speed of 200 r/min, digestion pressure of 0.5 MPa, and addition of 3% (relative to the mass fraction of lime) diethanol monoisopropanolamine (DEIPA), the prepared Ca(OH)₂ mass fraction is 92.1%, the specific surface area (BET) is 32.878 7 m²/g, the pore volume is 0.166 2 cm³/g, and the particle size is mainly concentrated below 10 μm. The pressure can mitigate the effect of DEIPA on the Ca(OH)₂ mass fraction in the sample to a certain extent. This study provides a theoretical basis for the dry-prepared Ca(OH)₂ with high specific surface area, which is of great significance for acid gas pollution treatment, sulfur-containing flue gas purification and related applications.

Road Materials and Others

Road Performance of Rice Husk Biochar Cement-Stabilized Crushed Stone

WANG Daming, ZHU Yewei, ZHANG Zixin, HONG Xinwen, MIAO Chunjie

2025, 44(8):  3105-3115.  doi:10.16552/j.cnki.issn1001-1625.2025.0168

Asbtract ( 56 )   PDF (9482KB) ( 21 )  

References | Related Articles | Metrics

The development of new green, low-carbon, and carbon-sequestering pavement materials is of great significance to realize of “dual carbon” strategic goals. To achieve energy conservation, emission reduction, and effective carbon sequestration, this study selected rice husk biochar (RHB) as an additive and applied to cement-stabilized crushed stone and conducted a series of tests, including unconfined compressive strength, splitting strength, bending tensile strength, compressive resilience modulus, frost resistance, drying shrinkage performance, and thermal shrinkage performance to investigate the influence of RHB on the performance of cement-stabilized crushed stone. The results show that when the RHB content is 5% (mass fraction), the road performance of cement-stabilized crushed stone is optimal. At this content, the 7 d unconfined compressive strength, 7 d splitting strength, and 28 d bending tensile strength increase by 49.3%, 20.9% and 6.5%, respectively, compared to the control group without RHB. Meanwhile, the drying shrinkage performance is significantly improved and the total drying shrinkage coefficient reduces by 21.8%. The porous structure of RHB can store a large amount of water, providing an excellent internal curing environment. It also participates in the hydration reaction and adsorbs hydration products together, making the products denser, thereby significantly enhancing the overall performance of cement-stabilized crushed stone.

Analysis of Damage and Deterioration of the Ming Great Wall Soil Site in Xiaoyuanmao of Inner Mongolia under Wind Erosion and Wind-Sand Erosion

HAO Yunhong, YUN Zeya, WU Rigen, FENG Wuyan, HOU Zhiguo

2025, 44(8):  3116-3126.  doi:10.16552/j.cnki.issn1001-1625.2025.0099

Asbtract ( 35 )   PDF (16094KB) ( 25 )  

References | Related Articles | Metrics

In view of the serious damage of the Ming Great Wall soil site in Xiaoyuanmao section of Qingshuihe County, Inner Mongolia under the influence of wind erosion and wind-sand erosion, this paper took erosion velocity, erosion time, sand falling rate and erosion angle as variables. The erosion degradation process of remolded site soil was studied by simulating wind erosion and wind-sand erosion tests, and the apparent morphology and internal pores of soil were detected by microscopic test. The results show that the mass loss of soil under wind-sand erosion is 20.23 times greater than that under wind erosion. Under wind-sand erosion, the erosion rate decreases first and then increases with the increase of sand falling rate, and increases with the increase of erosion rate. The erosion rate is higher under high wind speed with small angle and low wind speed with large angle erosion, and the erosion rate is lower under low wind speed with small angle and high wind speed with large angle erosion. Under the action of small angle cutting and large angle impact, the soil damage gradually increases from the surface to the inside. The pore type of soil is mainly conical pore. After erosion, the pore specific surface area, micropore volume, total pore volume and average pore size of soil increase, and the pore fractal dimension decreases, indicating that the internal damage of soil increases after erosion. The research results can provide reference for the protection and repair of the Ming Great Wall in this area.