摘要：
Arabica coffee, as one of the world's three native coffee species, requires rational planning for its growing areas to ensure ecological and sustainable agricultural development. This study aims to establish a decision-making framework using Geographic Information Systems (GIS) and Multi-Criteria Decision-Making (MCDM), with a focus on assessing the habitat suitability of Arabica coffee in Yunnan Province, China. The impacts of climate, topography, soil, and socio-economic factors were considered by selecting 13 criteria through correlation analysis. Indicator weights were determined using the Best-Worst Method (BWM), while weighted processing was conducted using the Base-Criterion Method (BCM). Sensitivity analysis was performed to verify the accuracy and stability of the model. Additionally, several decision models were evaluated to investigate regionalizing Arabica coffee habitats in Yunnan. The results highlighted that minimum temperature during the coldest month is crucial for evaluation purposes. The BWM-GIS model identified suitable areas comprising 13.55% of the total area as most suitable, 27.46% as suitable, and 59.00% as unsuitable, whereas corresponding values for the BCM-GIS model were 9.97%, 30.43%, and 59.59%. Despite employing different decision-making methods, both models yielded similar and consistent results. The suitable areas mainly encompass Dehong, Pu'er, Lincang, Xishuangbanna, Baoshan, southern Chuxiong, eastern Honghe, southern Yuxi, and parts of Wenshan. BWM-GIS achieved an area under curve (AUC) value of 0.891, while BCM-GIS obtained an AUC value of 0.890, indicating the stability and reliability of the models. Among them, the evaluation process of BCM-GIS was simpler and more realistic. Therefore, it has high feasibility and practical value in practical application. The findings from this study provide a significant scientific foundation for optimizing Yunnan Province.
通讯机构：
[Yang, X ] Y;Yangtze Univ, Sch Urban Construct, Jingzhou 434023, Peoples R China.
关键词：
Steel-UHPC composite structures;Stud connectors;Machine learning;Load-slip curve prediction;Push-out test
摘要：
Machine learning techniques have demonstrated significant potential in predicting the shear mechanical performance of stud connectors. However, predicting the load-slip curves of stud connectors in steel-ultrahigh-performance concrete (UHPC) composite structures remains a challenge. While some empirical models have been developed to describe the load-slip behavior of stud connectors, most are fitted to limited databases, leading to inadequate generalizability. This study presents a series of push-out tests on stud connectors encased in steel-UHPC composite structures, along with a comprehensive analysis of the load-slip curve characteristics derived from the experimental results. Subsequently, eight machine learning models were trained and tested using a database comprising 289 instances from push-out tests. Fourteen key factors were selected as input parameters, and three characteristic values including shear strength, initial shear stiffness, and peak slip were chosen as output parameters. The results indicated that the Extreme Gradient Boosting (XGBoost) model exhibited excellent performance in predicting shear strength and peak slip, with corresponding R² values of 0.988 and 0.814, respectively, while the Categorical Boosting (CatBoost) model performed best in predicting initial shear stiffness with an R² value of 0.867. Feature importance analysis using the Shapley Additive Explanations (SHAP) method highlighted that stud diameter was a critical factor affecting shear strength and initial shear stiffness, while stud height was a critical factor influencing the peak slip. Finally, based on the predicted characteristic values, an effective model was established for predicting the load-slip curve of stud connectors in steel-UHPC composite structures, which was validated to have good accuracy and applicability via the test results.
Machine learning techniques have demonstrated significant potential in predicting the shear mechanical performance of stud connectors. However, predicting the load-slip curves of stud connectors in steel-ultrahigh-performance concrete (UHPC) composite structures remains a challenge. While some empirical models have been developed to describe the load-slip behavior of stud connectors, most are fitted to limited databases, leading to inadequate generalizability. This study presents a series of push-out tests on stud connectors encased in steel-UHPC composite structures, along with a comprehensive analysis of the load-slip curve characteristics derived from the experimental results. Subsequently, eight machine learning models were trained and tested using a database comprising 289 instances from push-out tests. Fourteen key factors were selected as input parameters, and three characteristic values including shear strength, initial shear stiffness, and peak slip were chosen as output parameters. The results indicated that the Extreme Gradient Boosting (XGBoost) model exhibited excellent performance in predicting shear strength and peak slip, with corresponding R² values of 0.988 and 0.814, respectively, while the Categorical Boosting (CatBoost) model performed best in predicting initial shear stiffness with an R² value of 0.867. Feature importance analysis using the Shapley Additive Explanations (SHAP) method highlighted that stud diameter was a critical factor affecting shear strength and initial shear stiffness, while stud height was a critical factor influencing the peak slip. Finally, based on the predicted characteristic values, an effective model was established for predicting the load-slip curve of stud connectors in steel-UHPC composite structures, which was validated to have good accuracy and applicability via the test results.
摘要：
At present, China's prefabricated buildings have entered a period of comprehensive development. Starting from the investment decision-making stage of construction projects, this paper analyses the characteristics of prefabricated investment estimation and the relevant literature on the characteristics of prefabricated construction projects, uses the rough set attribute reduction algorithm to screen the key engineering characteristic factors, and establishes a BP neural network model optimized by genetic algorithm to estimate and analyze the investment of completed prefabricated construction projects. The results of the study show that the accuracy of the improved BP neural network prediction model is better than that of the standard BP neural network prediction model, and the results are more stable, which provides a more scientific and effective method for the investment estimation of prefabricated buildings projects.
期刊：
Journal of Coatings Technology and Research,2025年:1-9 ISSN：1935-3804
通讯作者：
Yan Xu<&wdkj&>Xiaoming Tan
作者机构：
[Qinyi Liu; Yan Xu; Xiaoming Tan; Man Zhang; Tao Fang] School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan City, China;[Jiaxuan He] School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan City, China
通讯机构：
[Yan Xu; Xiaoming Tan] S;School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan City, China<&wdkj&>School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan City, China
摘要：
The synthesis of dimethylaminopropylmethacrylamide-benzylammonium chloride (QD-BC), a kind of acrylamide quaternary ammonium salt, through the combination of N-dimethylamine propyl methacrylamide and benzyl chloride (BC) is presented in this paper. The structure of QD-BC was analyzed using FTIR, carbon spectrum, mass spectrometry and 1HNMR spectroscopy. The resulting product was then utilized for the preparation of light-cured antimicrobial coatings. The mechanical properties of the light-cured coatings were evaluated through drawing tests, etc. The antimicrobial efficacy of coatings with varying contents of QD-BC against E. coli and S. aureus was investigated. The results indicate that the coating with the QD-BC content of 7.2% exhibits maximum adhesion strength, reaching 0.87 MPa. Moreover, when the QD-BC content is 6%, the coating displays a hardness value of 5H while maintaining good flexibility throughout all formulations tested. The coating with QD-BC content of 7.5% shows the highest impact strength among all compositions studied. Furthermore, at respective concentrations of 7.5% and 4.2% for the E. coli and S. aureus testing strains, these coatings demonstrate complete antimicrobial activity with exceptional durability.
通讯机构：
[Li, C ] W;Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Peoples R China.
关键词：
Rock mechanic;Fractured rock mass;Prestressed bolt;CT scan;F-T cycle
摘要：
The freeze-thaw (F-T) damage characteristics of anchored fractured rock masses are different from those of fractured rock masses without bolts. To explore the F-T damage location and characterize zonal damage of anchored rock masses, two stages of F-T cycle tests were conducted for the samples with no bolt, 45 degrees bolt and 90 degrees bolt respectively. CT scan tests were performed before and after F-T cycling. Visual damage was qualitatively evaluated through 3D image reconstruction of CT data. The zonal damage characteristics of the samples were quantitatively analyzed using 2-d CT slices, areal porosities, and damage variables of each slice. The results show that the F-T cycles can cause damage in the rock zone, propagation zone, and anchor zone. The damage to samples with a bolt was relatively small, and the damage to the 90 degrees anchor samples was less severe than that to 45 degrees anchor samples. Compared with the samples with no bolts, some of the damage in the propagation zone of the samples with a bolt was transferred to the anchor zone through the bolt, which led to the deterioration of anchoring performance of the bolt. It is necessary to pay attention to the effective reinforcement range within a rock mass reinforced by bolting, and the rock mass outside the reinforcement range is more prone to crack propagation due to the increased frost heaving caused by prestress. The results provide a reference value for the reasonable design of anchorage engineering works in cold area.
通讯机构：
[Peng, H ] W;Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.
关键词：
Magnetic chitosan microspheres;Coking wastewater;Regeneration;Adsorption
摘要：
As a new type of polymer functional material, magnetic chitosan has been widely used in wastewater treatment. In this study, magnetic chitosan microspheres (MCMs) were prepared by reversed-phase microemulsion cross-linking technology, and the adsorption capacity of MCMs to organic pollutants with high chemical oxygen demand (COD) in coking wastewater was studied. Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS), brunauer - emmett - teller (BET), vibrating sample magnetometer (VSM) were characterized. The effects of Fe 3 O 4 magnetic nanoparticles (MNPs), pH and the amount of adsorbent on the adsorption properties of MCMs were investigated. The following conclusions are obtained: the MCMs prepared in this study are successfully encapsulated, and the MCMs have good magnetic properties; Meanwhile, the removal performance of COD is higher. When the addition amount of Fe 3 O 4 is 10 % of the mass fraction of chitosan, the maximum adsorption amount of COD by MCMs can reach 261.82 mg/g under the conditions of pH 7.5, reaction temperature 298 K and adsorption time 42 h. The adsorption kinetics can be described by a quasi-second-order kinetic model. In addition, after 4 times of adsorption-desorption processes, the adsorbent still has more than 40 % COD adsorption, and has good adsorption performance. In general, because of the high adsorption efficiency, strong regeneration and excellent magnetic separation performance, MCMs have practical application potential in sewage treatment, biomedicine and other fields.
As a new type of polymer functional material, magnetic chitosan has been widely used in wastewater treatment. In this study, magnetic chitosan microspheres (MCMs) were prepared by reversed-phase microemulsion cross-linking technology, and the adsorption capacity of MCMs to organic pollutants with high chemical oxygen demand (COD) in coking wastewater was studied. Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS), brunauer - emmett - teller (BET), vibrating sample magnetometer (VSM) were characterized. The effects of Fe 3 O 4 magnetic nanoparticles (MNPs), pH and the amount of adsorbent on the adsorption properties of MCMs were investigated. The following conclusions are obtained: the MCMs prepared in this study are successfully encapsulated, and the MCMs have good magnetic properties; Meanwhile, the removal performance of COD is higher. When the addition amount of Fe 3 O 4 is 10 % of the mass fraction of chitosan, the maximum adsorption amount of COD by MCMs can reach 261.82 mg/g under the conditions of pH 7.5, reaction temperature 298 K and adsorption time 42 h. The adsorption kinetics can be described by a quasi-second-order kinetic model. In addition, after 4 times of adsorption-desorption processes, the adsorbent still has more than 40 % COD adsorption, and has good adsorption performance. In general, because of the high adsorption efficiency, strong regeneration and excellent magnetic separation performance, MCMs have practical application potential in sewage treatment, biomedicine and other fields.
摘要：
This study investigates the breakpoint chlorination process and its impact on fungal spore and bacterial inactivation, focusing on the dynamic role of chloramines. Using Aspergillus niger and Bacillus subtilis as model microorganisms, a three-stage inactivation pattern driven by varying Cl 2 /N ratios was revealed. As Cl 2 /N increases, the overall disinfection efficiency improves, with free chlorine dominating bacterial inactivation beyond the breakpoint. However, for fungal spores, monochloramine (NH 2 Cl) remains the primary inactivating agent even as Cl 2 /N approaches and surpasses the breakpoint. At the peak chloramination stage, NH 2 Cl contributes 94 % of fungal inactivation, exploiting its superior ability to penetrate the robust, multilayered spore wall, compared to only 71 % for bacteria. In contrast, the oxidative potential of free chlorine is more effective against the simpler bacterial cell wall. These findings emphasize the pivotal role of peak chloramination in fungal control, as NH 2 Cl demonstrates superior cost−efficiency and inactivation performance during this stage. Although free chlorine provides broad−spectrum pathogen coverage beyond the breakpoint, targeting fungal spores effectively requires leveraging the unique advantages of NH 2 Cl. This study provides valuable insights for optimizing disinfection strategies by balancing Cl 2 /N ratios to enhance microbial inactivation while minimizing operational costs and disinfection byproduct risks.
This study investigates the breakpoint chlorination process and its impact on fungal spore and bacterial inactivation, focusing on the dynamic role of chloramines. Using Aspergillus niger and Bacillus subtilis as model microorganisms, a three-stage inactivation pattern driven by varying Cl 2 /N ratios was revealed. As Cl 2 /N increases, the overall disinfection efficiency improves, with free chlorine dominating bacterial inactivation beyond the breakpoint. However, for fungal spores, monochloramine (NH 2 Cl) remains the primary inactivating agent even as Cl 2 /N approaches and surpasses the breakpoint. At the peak chloramination stage, NH 2 Cl contributes 94 % of fungal inactivation, exploiting its superior ability to penetrate the robust, multilayered spore wall, compared to only 71 % for bacteria. In contrast, the oxidative potential of free chlorine is more effective against the simpler bacterial cell wall. These findings emphasize the pivotal role of peak chloramination in fungal control, as NH 2 Cl demonstrates superior cost−efficiency and inactivation performance during this stage. Although free chlorine provides broad−spectrum pathogen coverage beyond the breakpoint, targeting fungal spores effectively requires leveraging the unique advantages of NH 2 Cl. This study provides valuable insights for optimizing disinfection strategies by balancing Cl 2 /N ratios to enhance microbial inactivation while minimizing operational costs and disinfection byproduct risks.
关键词：
High alumina fly ash;Mechanical milling;Grinding kinetics;Microstructure;Activation mechanism
摘要：
Mechanical force can significantly enhance the physical and chemical activity of high-alumina fly ash (HAFA). Microparticle fly ash (MFA) was produced through mechanical ball milling of HAFA. The study concentrated on the particle size distribution of MFA after ball milling for 30–90 min and examined the impact of triethanolamine as a grinding aid. The particle size distribution (PSD), grinding kinetics, and mechanisms of microstructure evolution were analyzed. To verify the chemical activity of MFA, a high-alumina fly ash-based environmental material (EMFA) was synthesized. The results indicated that the particle proportion of 1–10 μm in MFA exceeded 50 %, and the RRB function was more suitable for describing the grinding kinetics of MFA. The mineral structure exhibited an increase in the content of amorphous substances, leading to the formation of amorphous active aluminum (Al). The microstructure of MFA displayed a combination of gel-like and fiber-like structures, including large smooth areas and fragment stacking. However, after 90 min of ball milling, a dense pore structure formed. The addition of triethanolamine accelerated the fragmentation of large particles and the formation of a secondary aggregate structure, with D50 remaining stable between 5.424 and 5.736 μm. The maximum compressive strength of EMFA reached 22.34 MPa, meeting the MU20 level of the Chinese standard "Solid Concrete Brick" (GB/T 21144-2023). This study provides crucial theoretical support for the modification, activation, and resource utilization of HAFA.
Mechanical force can significantly enhance the physical and chemical activity of high-alumina fly ash (HAFA). Microparticle fly ash (MFA) was produced through mechanical ball milling of HAFA. The study concentrated on the particle size distribution of MFA after ball milling for 30–90 min and examined the impact of triethanolamine as a grinding aid. The particle size distribution (PSD), grinding kinetics, and mechanisms of microstructure evolution were analyzed. To verify the chemical activity of MFA, a high-alumina fly ash-based environmental material (EMFA) was synthesized. The results indicated that the particle proportion of 1–10 μm in MFA exceeded 50 %, and the RRB function was more suitable for describing the grinding kinetics of MFA. The mineral structure exhibited an increase in the content of amorphous substances, leading to the formation of amorphous active aluminum (Al). The microstructure of MFA displayed a combination of gel-like and fiber-like structures, including large smooth areas and fragment stacking. However, after 90 min of ball milling, a dense pore structure formed. The addition of triethanolamine accelerated the fragmentation of large particles and the formation of a secondary aggregate structure, with D50 remaining stable between 5.424 and 5.736 μm. The maximum compressive strength of EMFA reached 22.34 MPa, meeting the MU20 level of the Chinese standard "Solid Concrete Brick" (GB/T 21144-2023). This study provides crucial theoretical support for the modification, activation, and resource utilization of HAFA.
摘要：
It is highly feasible to utilize phase change energy storage technology to construct a phase change material (PCM)-based thermal management system for electronic devices. In this paper, stearic acid (SA) was used as the PCM, and expanded graphite (EG) was chosen as the carrier to prepare SA/EG CPCM. The results showed that EG could prevent the melted SA from leaking, and the combination between SA and EG was only physical. When the mass fraction of EG was 11%, the SA/EG CPCM had good shape stability with a phase change temperature (T-m) of 67.2 degrees C, a phase change enthalpy (triangle H-m) of 204.4 J/g, and a significantly increased in thermal conductivity (6.432 W/(m<middle dot>K)). In addition, simulation test experiments showed that the peak value of the heating surface was weakened by about 20 degrees C in the heating stage after loading the CPCM on the electronic device. Therefore, the resultant SA/EG CPCM in this work had great application value.
期刊：
Construction and Building Materials,2025年482:141699 ISSN：0950-0618
通讯作者：
Xiang Duan
作者机构：
[Hongyang Deng; Jie Wu; Xiang Duan] School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430048, China;[Xinhua Cai] State Key Laboratory of Water Resources Engineering and Management, Wuhan University, Wuhan 430072, China;[Quanpeng Li] Wuhan Tianshi Construction Engineering Co., Ltd, Wuhan 430020, China;Southern Cement Co., Ltd, Wuxi 214223, China;[Kangyi Shi] School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430048, China<&wdkj&>Southern Cement Co., Ltd, Wuxi 214223, China
通讯机构：
[Xiang Duan] S;School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430048, China
摘要：
This study investigates the development of Alkali-activated Ultra-high performance concrete (AAUHPC) incorporating steel slag powder (SS), ground granulated blast furnace slag (GGBFS), silica fume, and hooked-end steel fibers to achieve sustainable, high-performance construction materials. The effects of SS content (0–70 %) and steel fiber volume fraction (0–2.0 %) on workability, mechanical properties, and microstructure were systematically evaluated through a combination of macroscopic performance tests (setting time, fluidity, compressive/flexural strength, and splitting tensile strength) and microstructural analyses (hydration heat, mercury intrusion porosimetry, X-ray computed tomography, scanning electron microscopy, and micro-hardness). Results reveal that AAUHPC containing 30 % SS and 2.0 % steel fibers achieves a fluidity of 190 mm and a compressive strength of 155.4 MPa at 28 days. Steel slag powder enhances the workability of fresh AAUHPC by extending setting time and improving fluidity, which can be attributed to its lower reactivity and reduced water demand compared to GGBFS. However, excessive SS content (>30 %) may dilute reactive phases and hinder hydration kinetics, leading to decreased mechanical strengths. Although hooked-end steel fibers slightly reduce fluidity, they significantly enhance toughness; specially, a 2.0 % volume fraction yields an 89.8 % increase in flexural strength (18.34 MPa) and a splitting tensile strength of 20.12 MPa, thereby enabling strain-hardening behavior comparable to cement-based UHPC. Microstructural analysis confirms a robust interfacial bonding between fibers and the alkali-activated matrix, facilitated by C-S-H and C-(N,K)-A-S-H gels. This phenomenon has significantly contributed to the high strength and toughness exhibited by AAUHPC. The findings underscore the potential of steel slag powder as a sustainable precursor for applications involving AAUHPC, while also demonstrating the compatibility of alkali-activated materials with hooked-end steel fibers.
This study investigates the development of Alkali-activated Ultra-high performance concrete (AAUHPC) incorporating steel slag powder (SS), ground granulated blast furnace slag (GGBFS), silica fume, and hooked-end steel fibers to achieve sustainable, high-performance construction materials. The effects of SS content (0–70 %) and steel fiber volume fraction (0–2.0 %) on workability, mechanical properties, and microstructure were systematically evaluated through a combination of macroscopic performance tests (setting time, fluidity, compressive/flexural strength, and splitting tensile strength) and microstructural analyses (hydration heat, mercury intrusion porosimetry, X-ray computed tomography, scanning electron microscopy, and micro-hardness). Results reveal that AAUHPC containing 30 % SS and 2.0 % steel fibers achieves a fluidity of 190 mm and a compressive strength of 155.4 MPa at 28 days. Steel slag powder enhances the workability of fresh AAUHPC by extending setting time and improving fluidity, which can be attributed to its lower reactivity and reduced water demand compared to GGBFS. However, excessive SS content (>30 %) may dilute reactive phases and hinder hydration kinetics, leading to decreased mechanical strengths. Although hooked-end steel fibers slightly reduce fluidity, they significantly enhance toughness; specially, a 2.0 % volume fraction yields an 89.8 % increase in flexural strength (18.34 MPa) and a splitting tensile strength of 20.12 MPa, thereby enabling strain-hardening behavior comparable to cement-based UHPC. Microstructural analysis confirms a robust interfacial bonding between fibers and the alkali-activated matrix, facilitated by C-S-H and C-(N,K)-A-S-H gels. This phenomenon has significantly contributed to the high strength and toughness exhibited by AAUHPC. The findings underscore the potential of steel slag powder as a sustainable precursor for applications involving AAUHPC, while also demonstrating the compatibility of alkali-activated materials with hooked-end steel fibers.
期刊：
Construction and Building Materials,2025年476:141240 ISSN：0950-0618
通讯作者：
Zhong, J;Sun, YB
作者机构：
[Zhong, Jing; Zhong, J; Sun, Shangyu; Zhang, Ming] Harbin Inst Technol, Sch Civil Engn, Harbin 150001, Peoples R China.;[Zhang, Ming] China State Construct Int Holdings Ltd, Hong Kong 999077, Peoples R China.;[Hu, Pengfei] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Peoples R China.;[Yao, Jie] China State Construct Hailong Technol Co Ltd, Shenzhen 518000, Peoples R China.;[Sun, Yubo; Sun, YB] Hong Kong Polytech Univ, Dept Civil & Environm Engn, Hong Kong 999077, Peoples R China.
通讯机构：
[Zhong, J ; Sun, YB ] H;Harbin Inst Technol, Sch Civil Engn, Harbin 150001, Peoples R China.;Hong Kong Polytech Univ, Dept Civil & Environm Engn, Hong Kong 999077, Peoples R China.
摘要：
The global surge in construction has intensified demand for natural silica sand (SS), causing shortages due to unsustainable extraction. This study explores the potential of using desert sand (DS) as an alternative to SS in producing ultra-high-performance alkali-activated concrete (UHPAAC), emphasizing the interactions between aggregates and the binding matrix. DS demonstrated a smoother surface morphology, finer particles, and a narrower gradation compared to SS. Substituting SS with DS at varying volume ratios improved the concentration of several elements in the pore solution of fresh mixtures. Samples with 10 vol% DS achieved the highest compressive strength, about 20 % higher than the SS reference mix. However, higher DS content reduced mechanical performance. Investigations of reaction products and microstructural characteristics revealed changes in the binder phase, including a lower Ca/Si ratio and improved local elastic modulus when DS was incorporated. Additionally, the smaller grain sizes of DS created numerous interfaces with the binding matrix, resulting in a more porous microstructure and declined micromechanical properties in the interfacial transition zone (ITZ) compared to SS. Nevertheless, the strategic incorporation of DS as a partial replacement for SS enhances both compressive and flexural strength while simultaneously reducing the environmental impact of UHPAAC production.
The global surge in construction has intensified demand for natural silica sand (SS), causing shortages due to unsustainable extraction. This study explores the potential of using desert sand (DS) as an alternative to SS in producing ultra-high-performance alkali-activated concrete (UHPAAC), emphasizing the interactions between aggregates and the binding matrix. DS demonstrated a smoother surface morphology, finer particles, and a narrower gradation compared to SS. Substituting SS with DS at varying volume ratios improved the concentration of several elements in the pore solution of fresh mixtures. Samples with 10 vol% DS achieved the highest compressive strength, about 20 % higher than the SS reference mix. However, higher DS content reduced mechanical performance. Investigations of reaction products and microstructural characteristics revealed changes in the binder phase, including a lower Ca/Si ratio and improved local elastic modulus when DS was incorporated. Additionally, the smaller grain sizes of DS created numerous interfaces with the binding matrix, resulting in a more porous microstructure and declined micromechanical properties in the interfacial transition zone (ITZ) compared to SS. Nevertheless, the strategic incorporation of DS as a partial replacement for SS enhances both compressive and flexural strength while simultaneously reducing the environmental impact of UHPAAC production.
期刊：
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING,2025年:116997 ISSN：2213-2929
通讯作者：
Jiawei Hu
作者机构：
[Jiawei Hu] School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430023, China;[Shaogang Hu] Hubei Key Laboratory of Regional Development and Environmental Response, College of Resources and Environmental Science, Hubei University, Wuhan 430062, China;[Yueming Han] Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
通讯机构：
[Jiawei Hu] S;School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430023, China
摘要：
For existing advantages in resource recovery and cost, anaerobic digestion (AD) is considered a proper technology to treat sludge. The insufficient efficiency of sludge AD however prevents its further application. This work reported a hybrid method by combining calcium hypochlorite (CH) with ultrasound (US) for sludge pretreatment to enhance the AD performance. Experimental data demonstrated that the optimal parameters of this co-treatment were CH at 0.08 g/g volatile suspended solids (VSS) coupled with US intensity of 1.0 W/mL, and relevant biomethane yield was 263.4 mL/g VSS, 15.2%, 23.1% and 56.6% higher than individual CH, individual US and control, respectively. Simulation results showed that methane production potential and rate both increased under CH + US condition. Mechanism analysis indicated that abundant dissolved organic matters were generated through high-efficiency hydrolysis when sludge was treated with CH + US, because extracellular polymeric substances (EPS) and microbial cells were both sufficiently disrupted in treatment process. Gene analysis revealed that functional microbes were generally enriched by the co-treatment, and their total abundance markedly improved from 11.89% to 24.87% under CH + US condition.
For existing advantages in resource recovery and cost, anaerobic digestion (AD) is considered a proper technology to treat sludge. The insufficient efficiency of sludge AD however prevents its further application. This work reported a hybrid method by combining calcium hypochlorite (CH) with ultrasound (US) for sludge pretreatment to enhance the AD performance. Experimental data demonstrated that the optimal parameters of this co-treatment were CH at 0.08 g/g volatile suspended solids (VSS) coupled with US intensity of 1.0 W/mL, and relevant biomethane yield was 263.4 mL/g VSS, 15.2%, 23.1% and 56.6% higher than individual CH, individual US and control, respectively. Simulation results showed that methane production potential and rate both increased under CH + US condition. Mechanism analysis indicated that abundant dissolved organic matters were generated through high-efficiency hydrolysis when sludge was treated with CH + US, because extracellular polymeric substances (EPS) and microbial cells were both sufficiently disrupted in treatment process. Gene analysis revealed that functional microbes were generally enriched by the co-treatment, and their total abundance markedly improved from 11.89% to 24.87% under CH + US condition.
期刊：
Journal of Building Engineering,2025年105:112474 ISSN：2352-7102
通讯作者：
Li, ZP
作者机构：
[Gong, Jing; Liu, Jiesheng] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Peoples R China.;[Gong, Jing] Wuchang Univ Technol, Intelligent Construct Coll, Wuhan 430223, Peoples R China.;[Chen, Chaoqian] Int Water Resources & Hydropower Engn Construct Co, Wuhan 460050, Peoples R China.;[Li, Zhipeng; Li, ZP] Washington State Univ, Dept Civil & Environm Engn, Pullman, WA 99164 USA.;[Li, Zhipeng] CarbonSilvanus Co, Pullman, WA 99163 USA.
通讯机构：
[Li, ZP ] W;Washington State Univ, Dept Civil & Environm Engn, Pullman, WA 99164 USA.
关键词：
Class F fly ash;Municipal solid waste incineration fly ash (MSWIA);Mechanical strength;Deconvoluted Fourier transform infrared (FTIR) spectroscopy;Hydration products
摘要：
Class F fly ash (FA) is often limited in its application in the concrete industry due to its low hydration reactivity. This study explores the synergistic utilization of municipal solid waste incineration fly ash (MSWIA) and FA to valorize these two industrial waste streams for application in the concrete industry, aimed to reduce the carbon footprint associated with extensive cement use. The study proposes replacing part of the cement with MSWIA and Class F FA, with a baseline mix ratio of MSWIA: FA: Cement = 40 %:40 %:20 %. In addition, silica fume (SF), nano-montmorillonite (nMMT), and calcium oxide (CaO) were added to the system to modify and activate the binder, with the goal of meeting practical engineering requirements. Experimental results indicate that the optimal dosages are 15 % SF/(FA + MSWIA), 0.3 % nMMT/(FA + MSWIA), and 3 % CaO/(FA + MSWIA), achieving a 28-day compressive strength of 21.1 MPa, which represents an increase of 186 % compared with the control group. Furthermore, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and deconvoluted Fourier transform infrared spectroscopy (FTIR) were used to investigate the effects of various variables on the microstructural morphology, hydration process, and hydration products of the paste samples. The results demonstrate that the addition of SF, nMMT, and CaO not only promotes the formation of highly polymerized hydration products, refines the pore structure, and improves the microstructural compactness but also significantly enhances the overall mechanical properties and durability of the cementitious system.
Class F fly ash (FA) is often limited in its application in the concrete industry due to its low hydration reactivity. This study explores the synergistic utilization of municipal solid waste incineration fly ash (MSWIA) and FA to valorize these two industrial waste streams for application in the concrete industry, aimed to reduce the carbon footprint associated with extensive cement use. The study proposes replacing part of the cement with MSWIA and Class F FA, with a baseline mix ratio of MSWIA: FA: Cement = 40 %:40 %:20 %. In addition, silica fume (SF), nano-montmorillonite (nMMT), and calcium oxide (CaO) were added to the system to modify and activate the binder, with the goal of meeting practical engineering requirements. Experimental results indicate that the optimal dosages are 15 % SF/(FA + MSWIA), 0.3 % nMMT/(FA + MSWIA), and 3 % CaO/(FA + MSWIA), achieving a 28-day compressive strength of 21.1 MPa, which represents an increase of 186 % compared with the control group. Furthermore, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and deconvoluted Fourier transform infrared spectroscopy (FTIR) were used to investigate the effects of various variables on the microstructural morphology, hydration process, and hydration products of the paste samples. The results demonstrate that the addition of SF, nMMT, and CaO not only promotes the formation of highly polymerized hydration products, refines the pore structure, and improves the microstructural compactness but also significantly enhances the overall mechanical properties and durability of the cementitious system.
摘要：
In recent years, the employment of rejuvenators and warm mix asphalt (WMA) additives for reclaimed asphalt pavement (RAP) has been recognized as a popular approach to increase the recycling rate of waste materials and promote the sustainable development of pavement engineering. However, the composition of warm mix recycled asphalt binder is complicated, and the microstructural changes brought about by the rejuvenators and WMA additives are critical in determining its macroscopic mechanical properties. This research focuses on the atomic modeling of the rejuvenators and WMA additives diffusion behavior of the warm mix recycled asphalt binder. The objective is to reveal the thermodynamic performance and diffusion mechanism of the WMA binder under the dual presence of rejuvenators and WMA additives. Three types of mutual diffusion systems (Aged and oil + virgin + wax, Aged + virgin + wax, and Aged and oil + virgin) were established, respectively, for a comparative investigation of the glass transition temperature, viscosity, thermodynamics, free volume, and diffusion behavior. The results indicate a 44.27% and 31.33% decrease in the glass transition temperature and apparent viscosity, respectively, after the incorporation of 5% oil rejuvenators in the Aged + virgin + wax asphalt binder, demonstrating the improved cracking resistance and construction workability. The presence of the RAP binder and organic WMA additives raised the cohesion of the asphalt binder and decreased self-healing ability and free volume, and these detrimental influences can be offset by the introduction of rejuvenators. The combined use of rejuvenators and organic WMA additives remarkably enhanced the de-agglomeration to asphaltenes, stimulated the activity of aged RAP macromolecular components, and ultimately improved the blending efficiency of virgin binders with the overall structure of RAP binders.
摘要：
The frequency–Bessel transformation method has significantly advanced the extraction of multimodal surface waves in seismic research. However, the presence of crossed artifacts in frequency–Bessel spectrograms, particularly when stations are regularly distributed, presents a persistent challenge. Various methods have been proposed to mitigate these artifacts, yet their diverse formulations often lead to confusion about their practical application and interrelations. This study aims to demystify these ambiguities by analyzing the existing formulations within a unified framework. We uncover that the apparent discrepancies among these methods primarily originate from the differing conventions across various studies. Consequently, we establish explicit mathematical relationships among these existing formulations. Moreover, we demonstrate that the reliance on numerical Hilbert transform can be avoided by maintaining only the causal component of cross-correlation functions. This approach simplifies the artifact removal process, enhancing the practical utility of frequency–Bessel spectrograms in geophysical analysis.
摘要：
Indiscriminate disposal of styrene butadiene styrene (SBS)-modified reclaimed asphalt pavement (RAP) leads to significant environmental issues and waste of valuable materials. To address this issue, this study explores and validates the feasibility of recycling the high-dosage SBS-modified RAP mixtures at high dosages into the surface layer of the high-grade asphalt pavement based on a warm mix asphalt-synchronous rejuvenation (WMA-SR) technology with a synchronous rejuvenation composite (SRC) synthesized. The optimum ratios of aromatic oil and triallyl isocyanurate (TAIC) in the SRC were first identified as 4.20 % and 4.82 %, respectively, using the FTIR peak area ratio restoration. Sasobit and Evotherm 3 G, two WMA additives, were afterwards combined with different types of rejuvenators to fabricate WMA-recycled asphalt mixtures at RAP dosages of 20 %, 40 %, and 60 %. Subsequently, a series of performance property tests were then conducted on the WMA-recycled asphalt mixtures, and a balanced mix design approach (BMD) was employed to identify the Sasobit as the suitable WMA additive and 40 % as the maximum SBS-modified RAP mixture dosage. Finally, the feasibility of the BMD on the RAP mixture design was proven through the long-term fatigue resistance tests. Evaluation results indicate that both the SRC and WMA additives are indispensable for the promotion of high-dosage SBS-modified RAP mixtures into high-grade asphalt pavement recycling.
Indiscriminate disposal of styrene butadiene styrene (SBS)-modified reclaimed asphalt pavement (RAP) leads to significant environmental issues and waste of valuable materials. To address this issue, this study explores and validates the feasibility of recycling the high-dosage SBS-modified RAP mixtures at high dosages into the surface layer of the high-grade asphalt pavement based on a warm mix asphalt-synchronous rejuvenation (WMA-SR) technology with a synchronous rejuvenation composite (SRC) synthesized. The optimum ratios of aromatic oil and triallyl isocyanurate (TAIC) in the SRC were first identified as 4.20 % and 4.82 %, respectively, using the FTIR peak area ratio restoration. Sasobit and Evotherm 3 G, two WMA additives, were afterwards combined with different types of rejuvenators to fabricate WMA-recycled asphalt mixtures at RAP dosages of 20 %, 40 %, and 60 %. Subsequently, a series of performance property tests were then conducted on the WMA-recycled asphalt mixtures, and a balanced mix design approach (BMD) was employed to identify the Sasobit as the suitable WMA additive and 40 % as the maximum SBS-modified RAP mixture dosage. Finally, the feasibility of the BMD on the RAP mixture design was proven through the long-term fatigue resistance tests. Evaluation results indicate that both the SRC and WMA additives are indispensable for the promotion of high-dosage SBS-modified RAP mixtures into high-grade asphalt pavement recycling.
摘要：
The effects of 0.5–3.0 wt% Cr 3 C 2 addition on the microstructure, mechanical properties, and magnetic properties of (Ti,W)C–30 wt% CoCrFeNiMo cermets were investigated in this study. All cermets predominantly exhibited Ti-based solid solution carbide ceramic grains, alongside an FCC solid solution phase. The increase of Cr 3 C 2 led to an increase in both the mean size and contiguity of the ceramic grains. The bending strength and fracture toughness decreased with increasing Cr 3 C 2 content. The hardness of the cermets increased up to 1.0 wt% Cr 3 C 2 , achieving a peak value of 91.8 HRA, before declining at higher Cr 3 C 2 concentrations. Cermets with Cr 3 C 2 contents of 0.5 wt%, 1 wt%, and 1.5 wt% displayed paramagnetic behavior at room temperature, with corresponding Curie temperatures of approximately 127 K, 168 K and 183 K, respectively. This behavior was attributed to the high concentrations of Cr, Ti, Mo, and W elements in the binder phase. However, the magnetic behavior transitioned to ferromagnetism as the Cr 3 C 2 concentration exceeds 1.5 wt%. Additionally, both the saturation magnetization and remanent magnetization increased with higher Cr 3 C 2 content .
The effects of 0.5–3.0 wt% Cr 3 C 2 addition on the microstructure, mechanical properties, and magnetic properties of (Ti,W)C–30 wt% CoCrFeNiMo cermets were investigated in this study. All cermets predominantly exhibited Ti-based solid solution carbide ceramic grains, alongside an FCC solid solution phase. The increase of Cr 3 C 2 led to an increase in both the mean size and contiguity of the ceramic grains. The bending strength and fracture toughness decreased with increasing Cr 3 C 2 content. The hardness of the cermets increased up to 1.0 wt% Cr 3 C 2 , achieving a peak value of 91.8 HRA, before declining at higher Cr 3 C 2 concentrations. Cermets with Cr 3 C 2 contents of 0.5 wt%, 1 wt%, and 1.5 wt% displayed paramagnetic behavior at room temperature, with corresponding Curie temperatures of approximately 127 K, 168 K and 183 K, respectively. This behavior was attributed to the high concentrations of Cr, Ti, Mo, and W elements in the binder phase. However, the magnetic behavior transitioned to ferromagnetism as the Cr 3 C 2 concentration exceeds 1.5 wt%. Additionally, both the saturation magnetization and remanent magnetization increased with higher Cr 3 C 2 content .
摘要：
Marine soft soils, characterized by high water content and low strength, present significant challenges to foundation stability. These soils often lead to settlement and uneven deformation, posing risks to infrastructure safety. This study tackles these challenges and promotes industrial waste utilization by developing a novel curing material for marine soft soils. The material consists of ground granulated blast furnace slag (GGBS), phosphogypsum (PG), and calcium carbide slag (CCS), and is compared to ordinary Portland cement (OPC). A D-optimal design was employed to establish regression equations for unconfined compressive strength (UCS) at 7 and 28 days. The interactions between factors were analyzed to optimize the mix ratio. The effects of different curing ages on the unconfined compressive strength, modulus of elasticity, moisture content, and pH of GPCOR solidified soft soil and cement solidified soil were investigated. The microstructure of the solidified soils was analyzed using SEM, XRD, FTIR, and BET techniques. The results indicated that the optimal GPC ratio was GGBS: PG: CCS = 64.81: 20.00: 15.19. After 28 days, GPCOR solidified soil exhibited superior UCS (4.48 MPa), 1.47 times greater than that of OPC solidified soil, and a deformation modulus 2.04 times higher. Furthermore, GPCOR exhibited a denser microstructure with smaller average pore sizes, improved durability, and better water retention than OPC. These findings underscore the potential of GPC as a sustainable alternative to conventional cement for reinforcing marine soft soils, promoting both soil stabilization and industrial waste resource utilization.
Marine soft soils, characterized by high water content and low strength, present significant challenges to foundation stability. These soils often lead to settlement and uneven deformation, posing risks to infrastructure safety. This study tackles these challenges and promotes industrial waste utilization by developing a novel curing material for marine soft soils. The material consists of ground granulated blast furnace slag (GGBS), phosphogypsum (PG), and calcium carbide slag (CCS), and is compared to ordinary Portland cement (OPC). A D-optimal design was employed to establish regression equations for unconfined compressive strength (UCS) at 7 and 28 days. The interactions between factors were analyzed to optimize the mix ratio. The effects of different curing ages on the unconfined compressive strength, modulus of elasticity, moisture content, and pH of GPCOR solidified soft soil and cement solidified soil were investigated. The microstructure of the solidified soils was analyzed using SEM, XRD, FTIR, and BET techniques. The results indicated that the optimal GPC ratio was GGBS: PG: CCS = 64.81: 20.00: 15.19. After 28 days, GPCOR solidified soil exhibited superior UCS (4.48 MPa), 1.47 times greater than that of OPC solidified soil, and a deformation modulus 2.04 times higher. Furthermore, GPCOR exhibited a denser microstructure with smaller average pore sizes, improved durability, and better water retention than OPC. These findings underscore the potential of GPC as a sustainable alternative to conventional cement for reinforcing marine soft soils, promoting both soil stabilization and industrial waste resource utilization.
通讯机构：
[Xu, Y ] W;Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.
摘要：
The surfaces of underwater ship hulls and aquaculture equipment, such as fish cages, are highly susceptible to damage from fouling organisms. Although traditional marine antifouling coatings exhibit effective antifouling properties, the leaching of antifouling agents into the marine environment can lead to pollution and ecological disruption. In this study, we prepared castor oil polyurethane (CO-PU) by reacting castor oil with isocyanate. We then incorporated self-synthesized acrylamide-based quaternary ammonium salts (QASs), specifically dimethyloctylaminopropyl methacrylamide-ammonium QD-BC and its polymer PQDBCAM, into the CO-PU resin to develop CO-PU marine antifouling coatings. By optimizing the formulation to enhance the cross-linking degree of the coating, we obtained coatings with improved mechanical properties and antifouling performance. The results indicate that, in comparison to the pure CO-PU coating, the hydrophilicity of the coating is enhanced, the flexibility is superior, the pencil hardness increases from 5H to 6H, and the adhesion of the PQDBCAM antifouling coating reaches a maximum of 4.79 MPa. All of the coatings demonstrated effectiveness in inhibiting the growth of Pseudomonas aeruginosa, diatoms, and protein attachment, and the increase of QASs leads to enhanced effects. This suggests that acrylamide QAS marine antifouling coatings have a certain degree of antifouling performance, and polymer-based quaternary ammonium PQDBCAM antifouling coatings show superior efficacy. After the 3.6% PQDBCAM coating was statically placed in diatoms for 7 days, the coverage area of diatoms was merely approximately 22.3% and the protein adsorption amount on the surface of the antifouling coating was 31.72 μg/cm(2). The coating could maintain its integrity after 3 months and still exhibit excellent antibacterial effects. The antifouling effect was more durable, effectively reducing the maintenance times of ships and the cleaning frequency of aquaculture equipment.
摘要：
In the engineering domain, the detection of damage in high-strength bolts is critical for ensuring the safe and reliable operation of equipment. Traditional manual inspection methods are not only inefficient but also susceptible to human error. This paper proposes an automated bolt damage identification method leveraging AIGC (Artificial Intelligence Generated Content) technology and object detection algorithms. Specifically, we introduce the application of AIGC in image generation, focusing on the Stable Diffusion model. Given that the quality of bolt images generated directly by the Stable Diffusion model is suboptimal, we employ the LoRA fine-tuning technique to enhance the model, thereby generating a high-quality dataset of bolt images. This dataset is then used to train the YOLO (You Only Look Once) object detection algorithm, demonstrating significant improvements in both accuracy and recall for bolt damage recognition. Experimental results show that the LoRA fine-tuned Stable Diffusion model significantly enhances the performance of the YOLO algorithm, providing an efficient and accurate solution for automated bolt damage detection. Future work will concentrate on further optimizing the model to improve its robustness and real-time performance, thereby better meeting the demands of practical industrial applications.
