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Interactions between Superplasticizer and Release Agents at the Concrete/Formwork Interface
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作者 Samir Bouharoun Yannick Vanhove +2 位作者 Chafika Djelal Pascale De Caro Isabelle Dubois 《Materials Sciences and Applications》 2012年第6期384-389,共6页
Improving the knowledge of rheological and tribological characteristics of fresh concrete is important to contribute to the progress of construction sites and the final quality of the work. The objective of this study... Improving the knowledge of rheological and tribological characteristics of fresh concrete is important to contribute to the progress of construction sites and the final quality of the work. The objective of this study is to identify the effect of a superplasticizer based on polycarboxylic ether on the tribological behavior of fresh concrete at the concrete/formwork and concrete/oil/formwork interfaces. Friction tests on fresh concrete were carried out using a plan/plan tribometer. In order to study the behavior of the superplasticizer close to the formwork, three concretes with 30% of paste and different dosage of superplasticizer were formulated. The results show that the increase of the dosage of superplasticizer reduces the friction stress. The properties of the superplasticizer generate a deflocculating action of concrete grains and lead to a stabilisation of the soap-oil micellae present in the vicinity of the formwork. Thus, the efficiency of superplasticizer depends on the quantity of fines, on the quantity of soap formed and so, on the release agent formulation. 展开更多
关键词 TRIBOLOGY concrete/formwork INTERFACE concrete/Oil/formwork INTERFACE SUPERPLASTICIZER Release Agent PHYSICOCHEMICAL
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Recent Efforts on the Compressive and Tensile Strength Behavior of Thermoplastic-Based Recycled Aggregate Concrete toward Sustainability in Construction Materials
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作者 Mahmoud Alhashash Abdullah Alariyan +3 位作者 Ameen Mokhles Youns Favzi Ghreivati Ahed Habib Maan Habib 《Structural Durability & Health Monitoring》 2026年第1期23-46,共24页
Concrete production often relies on natural aggregates,which can lead to resource depletion and environmental harm.In addition,improper disposal of thermoplastic waste exacerbates ecological problems.Although signific... Concrete production often relies on natural aggregates,which can lead to resource depletion and environmental harm.In addition,improper disposal of thermoplastic waste exacerbates ecological problems.Although significant attention has recently been given to recycling various waste materials into concrete,studies specifically addressing thermoplastic recycled aggregates are still trending.This underscores the need to comprehensively review existing literature,identify research trends,and recognize gaps in understanding the mechanical performance of thermoplastic-based recycled aggregate concrete.Accordingly,this review summarizes recent investigations focused on the mechanical properties of thermoplastic-based recycled aggregate concrete,emphasizing aspects such as compressive strength,tensile behavior,modulus of elasticity,and durability characteristics.The primary aim is to consolidate scattered research findings,identify key parameters influencing mechanical behavior,and propose future research directions.Understanding the influence of recycled thermoplastic aggregates on concrete performance significantly supports sustainable construction practices by reducing dependency on virgin aggregates and mitigating environmental impacts associated with waste disposal.In addition,assessing mechanical performance contributes to confidence in the practical application,encouraging the broader adoption of thermoplastic-based recycled aggregate concrete in construction projects.Through this critical synthesis,the review guides researchers and industry practitioners toward informed decisions on the feasibility and reliability of integrating thermoplastic waste into concrete,thereby promoting sustainable infrastructure development. 展开更多
关键词 THERMOPLASTIC RECYCLING AGGREGATES concrete SUSTAINABILITY
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Durability of SAP-modified Fully Recycled Concrete under Freeze-Thaw Cycles
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作者 XING Zhengguang PENG Erxing +3 位作者 ZHANG Mingyi PEI Wansheng HU Xiaoying SUN Haoyue 《Journal of Wuhan University of Technology(Materials Science)》 2026年第1期179-188,共10页
This study introduces superabsorbent polymers(SAP)into recycled concrete and,through freeze-thaw cycle tests,unconfined compressive strength tests,and nuclear magnetic resonance(NMR)analysis,evaluates the freeze-thaw ... This study introduces superabsorbent polymers(SAP)into recycled concrete and,through freeze-thaw cycle tests,unconfined compressive strength tests,and nuclear magnetic resonance(NMR)analysis,evaluates the freeze-thaw resistance and durability of recycled concrete samples under varying freeze-thaw cycles.The results indicate that an appropriate addition of SAP significantly enhances the freeze-thaw resistance of recycled concrete.After 200 freeze-thaw cycles,the RS0.6 sample retained good surface integrity,demonstrating the best performance.Compared to NAC,its mass loss decreased by 1.16%,the relative dynamic modulus improved by 7.01%,and the compressive strength loss rate decreased by 5.41%.Additionally,T2 spectrum analysis revealed that adding SAP optimized the pore structure of recycled concrete and mitigated pore development during freeze-thaw cycles.As the number of freeze-thaw cycles increased,the RS0.3 and RS0.6 samples demonstrated superior frost resistance compared to NAC.However,an excessive amount of SAP increased pore expansion during subsequent freeze-thaw cycles,ultimately weakening frost resistance. 展开更多
关键词 Recycled concrete SAP freeze-thaw cycle pore structure DURABILITY
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Drying Shrinkage and Creep Properties of Recycled Sand Concrete
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作者 SHI Henan LI Huajian +2 位作者 HUANG Fali YANG Zhiqiang DONG Haoliang 《Journal of Wuhan University of Technology(Materials Science)》 2026年第2期403-413,共11页
This study aimed to investigate the influence of recycled sand(RS)content and water-binder ratio on the long term performance of recycled sand concrete(RSC).A 220 days drying shrinkage and creep test of RSC was conduc... This study aimed to investigate the influence of recycled sand(RS)content and water-binder ratio on the long term performance of recycled sand concrete(RSC).A 220 days drying shrinkage and creep test of RSC was conducted,and the microhardness of ITZ were analyzed to explain the differences in performance.The experimental results indicate that,when RS content is 50%,the drying shrinkage and creep strain of RSC is the smallest.This is attributed to the highest microhardness in the ITZ when the RS content is 50%.When the RS content is 100%,the shrinkage and creep strains increase due to the high water absorption of RS,which leads to the evaporation of additional water and the deterioration of the ITZ.As the water-binder ratio increases,the drying shrinkage and creep strain of RSC with different RS content increases.According to the EC2 specification and the CEB-FIP specification,the drying shrinkage and creep prediction models for RSC have been established. 展开更多
关键词 recycled sand concrete drying shrinkage CREEP ITZ prediction model
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Effect of Fly Ash on Frost Resistance and Regeneration of Recycled Aggregate Concrete
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作者 ZHU Pinghua CHRISTIAN Bihoza +3 位作者 CHEN Xintong WANG Xingjie LIU Hui YAN Xiancui 《Journal of Wuhan University of Technology(Materials Science)》 2026年第1期138-146,共9页
We investigated the effects of fly ash(FA)content on the mechanical properties of recycled aggregate concrete(RAC)and its regeneration potential under freeze and thaw(F-T)cycles.The physical properties of second-gener... We investigated the effects of fly ash(FA)content on the mechanical properties of recycled aggregate concrete(RAC)and its regeneration potential under freeze and thaw(F-T)cycles.The physical properties of second-generation recycled concrete aggregates(RCA)were used to analyze the regeneration potential of RAC after F-T cycles.Scanning electron microscopy was used to study the interfacial transition zone microstructure of RAC after F-T cycles.Results showed that adding 20%FA to RAC significantly enhanced its mechanical properties and frost resistance.Before the F-T cycles,the compressive strength of RAC with 20%FA reached 48.3 MPa,exceeding research strength target of 40 MPa.A majority of second-generation RCA with FA had been verified to attain class Ⅲ,which enabled their practical application in non-structural projects such as backfill trenches and road pavement.However,the second-generation RCA with 20%FA can achieve class Ⅱ,making it ideal for 40 MPa structural concrete. 展开更多
关键词 fly-ash content frost resistance recycled aggregate concrete MICROSTRUCTURE regeneration potential
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Effect of Lithium Hydroxide and Borax on Properties of Low Alkali Sulphoaluminate Special Concrete
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作者 CHEN Tingchao LIU Rongjin +3 位作者 JING Daiyan ZHAO Yingren ZHEN Yixing WEI Jiazhan 《Journal of Wuhan University of Technology(Materials Science)》 2026年第1期247-257,共11页
The engineering application of low-alkali sulphoaluminate cement(L-SAC)is hindered due to the difficulty in adjusting the setting and hardening time.In this paper,lithium hydroxide and borax are mixed into L-SAC to re... The engineering application of low-alkali sulphoaluminate cement(L-SAC)is hindered due to the difficulty in adjusting the setting and hardening time.In this paper,lithium hydroxide and borax are mixed into L-SAC to regulate its setting and hardening process,so as to prepare a sulphoaluminate concrete material with high early strength and high fluidity.The effects of the ratio of lithium hydroxide to borax on the properties of L-SAC concrete were studied by hydration heat,XRD,TG-DTG,SEM and MIP.The experimental results show that the slump increases with the increase of borax content,and the early(3 h)strength increases with the increase of lithium hydroxide content.When 0.05% lithium hydroxide and 0.4% borax are added,the 0.5 h slump reaches 195 mm,and the 3 h compressive strength reaches 15.9 MPa.The increase of lithium hydroxide will promote the formation of early hydration products AFt and AH3 gel and accelerate the hydration process,while borax will inhibit the dissolution and hydration of cement and delay the setting and hardening process of concrete.The combination of the two ensures that the concrete has the characteristics of high early strength and high fluidity,and the early workability and mechanical properties can be controlled by the mix ratio.For long-term mechanical properties,the special concrete does not produce AFm,which can ensure the continuous development of strength. 展开更多
关键词 low-alkali sulphoaluminate cement concrete high early strength high flow ETTRINGITE
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Stress Uniformity and Dynamic Mechanical Properties of Cubic Concretes in SHPB Tests
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作者 LI Mei CUI Jian +1 位作者 SHI Yanchao TANG Baijian 《Journal of Wuhan University of Technology(Materials Science)》 2026年第1期162-170,共9页
Based on the split hopkinson pressure bar(SHPB)tests results,the cubic specimens have been numerically modeled in this paper to investigate the impact of key factors,such as the rise time,duration,and incident pulse s... Based on the split hopkinson pressure bar(SHPB)tests results,the cubic specimens have been numerically modeled in this paper to investigate the impact of key factors,such as the rise time,duration,and incident pulse shape,on achieving stress uniformity.After analysis,the paper provides actionable methods aimed at optimizing the conditions for stress uniformity within the cubic specimen.Finally,the lateral inertia effect of cubic specimen has been scrutinized to address the existing gap in this academic area. 展开更多
关键词 concrete cubic specimen stress uniformity impact loads lateral inertia effect
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Fatigue of Recycled Concrete Aggregate Asphalt Mixture under Temperature-Humidity Coupling
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作者 CHEN Hao ZHENG Wenhua +5 位作者 JI Jie DONG Zhilei YU Yening WANG Zihao CHEN Meng ZHOU Wenjuan 《Journal of Wuhan University of Technology(Materials Science)》 2026年第2期523-536,共14页
A comprehensive full-sieve-hole grading correction method was used to adjust aggregate gradings.The fatigue properties of recycled concrete aggregate(RCA)asphalt mixtures were investigated using an improved indirect t... A comprehensive full-sieve-hole grading correction method was used to adjust aggregate gradings.The fatigue properties of recycled concrete aggregate(RCA)asphalt mixtures were investigated using an improved indirect tensile fatigue test under temperature-humidity coupling based on 20-year meteorological data of Beijing,and the degeneration mechanism was further explored by scanning electron microscopy and energy-dispersive spectroscopy.The experimental results indicate that replacing 5-20 mm coarse limestone aggregate(LA)with RCA at a 50% substitution volume can mitigate the impact of RCA variations on the asphalt mixture proportioning design.All RCA asphalt mixtures have lower initial fatigue properties than the LA asphalt mixture.However,under temperature-humidity coupling,the long-term fatigue property of an RCA asphalt mixture with a low proportion of recycled brick exceeds that of the LA asphalt mixture,and the fatigue life decline rate of the RCA asphalt mixture during 10-year service decreases by approximately 25%.This is due to the penetration of the asphalt mortar into the RCA through the pores and cracks on the RCA surface.It forms an interfacial transition zone composed of asphalt mortar and cement mortar and further reduces the mixture damage caused by the water and freeze-thaw conditions. 展开更多
关键词 recycled concrete aggregate asphalt mixture temperature-humidity coupling fatigue property micromechanism
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Evaluation of Deterioration Law and Reliability of Concrete after Durability Improvement Based on Wiener Theory
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作者 SHI Hongzhuang SU Fuyun +3 位作者 QIAO Hongxia ZHANG Lei FU Yong YANG Xiaosen 《Journal of Wuhan University of Technology(Materials Science)》 2026年第1期147-161,共15页
To study the durability of concrete in harsh environments in Northwest China,concrete was prepared with various durability-improving materials such as concrete anti-erosion inhibitor(SBT-TIA),acrylate polymer(AP),supe... To study the durability of concrete in harsh environments in Northwest China,concrete was prepared with various durability-improving materials such as concrete anti-erosion inhibitor(SBT-TIA),acrylate polymer(AP),super absorbent resin(SAP).The erosion mode and internal deterioration mechanism under salt freeze-thaw cycle and dry-wet cycle were explored.The results show that the addition of enhancing materials can effectively improve the resistance of concrete to salt freezing and sulfate erosion:the relevant indexes of concrete added with X-AP and T-AP are improved after salt freeze-thaw cycles;concrete added with SBTTIA shows optimal sulfate corrosion resistance;and concrete added with AP displays the best resistance to salt freezing.Microanalysis shows that the increase in the number of cycles decreases the generation of internal hydration products and defects in concrete mixed with enhancing materials and improves the related indexes.Based on the Wiener model analysis,the reliability of concrete with different lithologies and enhancing materials is improved,which may provide a reference for the application of manufactured sand concrete and enhancing materials in Northwest China,especially for the study of the improvement effects and mechanism of enhancing materials on the performance of concrete. 展开更多
关键词 manufactured sand concrete durability enhancement enhancing materials reliability analysis
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Effect of Sheath Modeling on Unbonded Post-Tensioned Concrete under Blast Loads
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作者 Hyeon-Sik Choi Min Kyu Kim +1 位作者 Jiuk Shin Thomas H.-K.Kang 《Computer Modeling in Engineering & Sciences》 2026年第1期399-415,共17页
Unbonded post-tensioned(PT)concrete systems are widely used in safety-critical structures,yet model-ing practices for prestress implementation and tendon-concrete interaction remain inconsistent.This study investigate... Unbonded post-tensioned(PT)concrete systems are widely used in safety-critical structures,yet model-ing practices for prestress implementation and tendon-concrete interaction remain inconsistent.This study investigates the effects of sheath(duct)implementation and confinement assumptions through nonlinear finite element analysis.Four modeling cases were defined,consisting of an explicit sheath without tendon-concrete confinement(S)and three no-sheath variants with different confinement levels(X,N,A).One-way beams and two-way panels were analyzed,and panel blast responses were validated against experimental results.In both beams and panels,average initial stress levels were similar across models,through local stress concentrations appeared when the sheath was modeled.Under blast loading,these local effects became critical,and the sheath-implemented model reproduced experimental behavior most accurately,whereas non-implemented models deviated.Reduced blast intensity diminished the differences among models,thereby reaffirming that sheath-induced localization and damage propagation are critical factors.These findings highlight the importance of explicit sheath implementation for realistic numerical assessment of unbonded PT structures under extreme loads. 展开更多
关键词 Unbonded post-tensioned concrete sheath implementation blast loading finite element analysis
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Visual Interpretation of Crucial Influencing Factors in Sea Sand Concrete Strength with Machine Learning Prediction
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作者 ZHU Naishu JIN Fengnian +6 位作者 OU Zhongwen DAI Yinsuo LIU Yong ZHANG Zhi MA Linjian HE Huguang ZHANG Hansong 《Journal of Wuhan University of Technology(Materials Science)》 2026年第2期472-482,共11页
We employed machine learning approaches and visualization interpretation methods to explore the influencing factors of the compressive strength of sea sand concrete to attain a better understanding of the inherent law... We employed machine learning approaches and visualization interpretation methods to explore the influencing factors of the compressive strength of sea sand concrete to attain a better understanding of the inherent laws of concrete mix design.Four models,including random forest,Cat Boost,XGBoost,and deep neural network,were trained.The experimental results demonstrate that the XGBoost model performs the best in predicting the strength of sea sand concrete.Its R^(2)value reached 0.9999,and evaluation indexes such as MAPE,RMSE,MAE,and MSE are superior to those of other models.The principal component analysis(PCA)was conducted to visually analyze the structure and distribution of the original feature data,and Pearson correlation coefficient analysis and Shapley additive explanation(SHAP)were utilized to explore the impact of input characteristics on the strength of sea sand concrete.SHAP analysis is more conducive to revealing the nonlinear effects of various characteristics on the model prediction results,especially that particle size of stone has significant impacts on the strength of sea sand concrete.In addition,experimental verification was carried out to confirm the accuracy of the optimized training model.These findings offer some insights for the future design and application of sea sand in high-performance marine and coastal infrastructure. 展开更多
关键词 sea sand concrete compressive strength machine learning SHAP mix ratio design
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Experimental evaluation of high performance concrete cladding based on shaking table tests
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作者 Wang Yanhua Zhang Mingzhou +2 位作者 He Junze Jin Yihan Xu Yang 《Earthquake Engineering and Engineering Vibration》 2026年第1期111-122,共12页
Severe failures of nonstructural components have occurred during previous earthquakes.Claddings are one of the most widely used nonstructural component and are installed in many modern buildings;therefore,an evaluatio... Severe failures of nonstructural components have occurred during previous earthquakes.Claddings are one of the most widely used nonstructural component and are installed in many modern buildings;therefore,an evaluation of their seismic performance is important and cannot be ignored.To investigate the seismic performance of large-sized high performance concrete cladding(HPCC),a series of full-scale experimental tests were conducted using a unidirectional shaking table.A steel supporting frame was used to install the HPCCs and reproduce the effects of the building under earthquake.The tests were divided into two parts:in-plane(IP)testing and out-plane(OP)testing.Three recorded accelerograms,one artificial accelerogram,and one sinusoidal accelerogram were used to conduct the shaking table tests.The results show that the maximum recorded IP responses of acceleration and interstory drift ratio were 1.04 g and 1/97,while the OP responses were 1.02 g and 1/51.The HPCCs functioned well throughout the entire experimental protocol.The fundamental frequency of the HPCCs systems rarely changed after the tests. 展开更多
关键词 nonstructural components high performance concrete CLADDING seismic performance shaking table tests
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Mechanical Properties and Mechanisms of Nano-calcium Carbonate-modified Ultra High Performance Concrete with Large Amounts of Ceramic Waste
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作者 ZHANG Liqing LI Xiyou +3 位作者 WEI Luofei XIONG Jingang XIONG Xinfu WANG Yunyang 《Journal of Wuhan University of Technology(Materials Science)》 2026年第2期553-562,共10页
Utilization of ceramic wastes to fabricate concrete can not only effectively dispose the wastes,but also reduce the energy and source consumptions.Therefore,we fabricated a green ultra high performance concrete using ... Utilization of ceramic wastes to fabricate concrete can not only effectively dispose the wastes,but also reduce the energy and source consumptions.Therefore,we fabricated a green ultra high performance concrete using ceramic waste powder(CWP)to replace 55%of cement,and ceramic waste aggregate(CWA)to replace 100%natural quartz sand.However,high content of ceramic wastes will harm the concrete performance including workability and mechanical properties.Therefore,a low-cost and low carbon nano-calcium carbonate(NC)was introduced to compensate for the defects caused by large amounts of CWP and CWA to workability and mechanical behavior.The experimental results show that the workability of ultra high performance concrete with large amounts of CWP and CWA(UHPCLCC)increases by 28.57%with NC content of 5%.Moreover,the flexural strengths,fracture energy,compressive strengths,and compressive toughness of UHPCLCC increase up to 29.6%,56.5%,20.4%,and 37.6%,respectively,which is caused by the nano-core effect of NC. 展开更多
关键词 ultra high performance concrete ceramic waste nano-calcium carbonate mechanical properties MECHANISMS
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Basic Mechanical Properties and Microstructure of Sustainable Recycled Coral Aggregate Concrete
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作者 WANG Lei LU Jiahui +5 位作者 ZHANG Jiwang YI Jin ZHU Dexiang HUANG Dongming QIN Yan LI Yajie 《Journal of Wuhan University of Technology(Materials Science)》 2026年第1期217-226,共10页
Crushing waste coral concrete into recycled aggregates to create recycled coral aggregate concrete(RCAC)contributes to sustainable construction development on offshore islands and reefs.To investigate the impact of re... Crushing waste coral concrete into recycled aggregates to create recycled coral aggregate concrete(RCAC)contributes to sustainable construction development on offshore islands and reefs.To investigate the impact of recycled coral aggregate on concrete properties,this study performed a comprehensive analysis of the physical properties of recycled coral aggregate and the basic mechanical properties and microstructure of RCAC.The test results indicate that,compared to coral debris,the crushing index of recycled coral aggregate was reduced by 9.4%,while porosity decreased by 33.5%.Furthermore,RCAC retained the early strength characteristics of coral concrete,with compressive strength and flexural strength exhibiting a notable increase as the water-cement ratio decreased.Under identical conditions,the compressive strength and flexural strength of RCAC were 12.7% and 2.5% higher than coral concrete's,respectively,with porosity correspondingly reduced from 3.13% to 5.11%.This enhancement could be attributed to the new mortar filling the recycled coral aggregate.Scanning electron microscopy(SEM)analysis revealed three distinct interface transition zones within RCAC,with the‘new mortar-old mortar’interface identified as the weakest.The above findings provided a reference for the sustainable use of coral concrete in constructing offshore islands. 展开更多
关键词 recycled coral aggregate sustainable concrete mechanical properties MICROSTRUCTURE interfacial transition zone
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Fatigue behavior of ballastless track concrete in high-speed railways under different operating speeds
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作者 Jiaxin Wen Huajian Li +2 位作者 Henan Shi Fali Huang Zhen Wang 《Railway Engineering Science》 2026年第1期149-158,共10页
This study investigates the influence of loading frequency on the fatigue behavior of ballastless track concrete for high-speed railways,aiming to support the development of concrete capable of withstanding higher ope... This study investigates the influence of loading frequency on the fatigue behavior of ballastless track concrete for high-speed railways,aiming to support the development of concrete capable of withstanding higher operational speeds.Fatigue tests were conducted at loading frequencies ranging from 5 to 40 Hz,with a focus on fatigue life,damage evolution,energy dissipation,and residual fatigue strain in the concrete.The results indicate that between 5 and 15 Hz,the fatigue life and energy dissipation remain relatively stable,with minimal damage evolution and small residual strains.As the frequency increases to 15-20 Hz,the fatigue life and energy dissipation gradually decrease,while damage accumulation and residual strain increase.Beyond 20 Hz,both fatigue life and energy dissipation decrease rapidly,damage accumulation becomes more pronounced,and residual strain continues to rise.These phenomena are primarily attributed to the increased strain rate and load change rate at higher frequencies,which affect the microstructure evolution and lead to reduced fatigue performance. 展开更多
关键词 Ballastless tracks concrete Flexural fatigue Loading frequency Damage evolution Residual strain
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Integrating Carbonation Durability and Cover Scaling into Low-Carbon Concrete Design:A New Framework for Sustainable Slag-Based Mixtures
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作者 Kang-Jia Wang Hongzhi Zhang +2 位作者 Runsheng Lin Jiabin Li Xiao-Yong Wang 《Computer Modeling in Engineering & Sciences》 2026年第1期416-435,共20页
Conventional low-carbon concrete design approaches have often overlooked carbonation durability and the progressive loss of cover caused by surface scaling,both of which can increase the long-term risk of reinforcemen... Conventional low-carbon concrete design approaches have often overlooked carbonation durability and the progressive loss of cover caused by surface scaling,both of which can increase the long-term risk of reinforcement corrosion.To address these limitations,this study proposes an improved design framework for low-carbon slag concrete that simultaneously incorporates carbonation durability and cover scaling effects into the mix proportioning process.Based on experimental data,a linear predictive model was developed to estimate the 28-day compressive strength of slag concrete,achieving a correlation coefficient of R=0.87711 and a root mean square error(RMSE)of 7.55 MPa.The mechanism-based equation exhibits strong physical interpretability,as each parameter corresponds to a clear physical process,satisfying the requirements of design codes for physical significance.By integrating the strength and carbon-emission models,the carbon-emission efficiency was further analyzed.Across all water–binder ratios(0.3,0.4,0.5),CO_(2) emissions per unit strength decreased steadily with increasing slag content,indicating that carbon efficiency is primarily governed by slag replacement rather than the water/binder ratio.Four design cases,all with a design strength of 30 MPa,were then evaluated to illustrate the combined effects of carbonation and scaling.In Case 1,without considering carbonation durability,the carbonation depth after 50 years exceeded the 25 mm cover,leading to potential corrosion.In Case 2,when carbonation durability was considered,the required actual strength increased to 31.28 MPa.When mild cover scaling of 3 mm was introduced(Case 3),the required strength rose to 34.59 MPa,and under severe scaling of 10 mm(Case 4),it increased to 45.73 MPa.These results indicate that intensified scaling demands higher strength and lower water/binder ratios to maintain durability.Overall,the proposed framework quantitatively balances strength,durability,and embodied carbon,supporting sustainable low-carbon concrete design. 展开更多
关键词 Low-CO_(2)concrete SLAG CARBONATION cover scaling optimal design
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Seismic design and performance of building structures with self-centering steel-concrete hybrid single-pier coupled walls
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作者 Mojtaba Farahi Fabio Freddi Massimo Latour 《Resilient Cities and Structures》 2026年第1期85-101,共17页
In response to the demand for seismic-resilient structures,various innovative solutions have emerged to reduce local damage and residual deformations,facilitating repair operations in the aftermath of high-intensity e... In response to the demand for seismic-resilient structures,various innovative solutions have emerged to reduce local damage and residual deformations,facilitating repair operations in the aftermath of high-intensity earth-quakes.This paper examines the seismic performance of a steel-concrete hybrid wall system equipped with a selfcentering solution to mitigate earthquake-induced residual deformations.The considered hybrid system includes a Reinforced Concrete(RC)shear wall with two steel side columns connected by coupling steel beams.In this study,a novel type of coupling beams featuring a friction-damped self-centering system is implemented.The system is referred to as Self-Centering Hybrid Single-Pier Coupled Wall(SC-SP-HCW)and aims to minimize damage and residual deformations after earthquakes,which in turn facilitates repairs and enhances seismic resilience.Unlike conventional self-centering coupling beams with post-tensioned tendons,the self-centering configuration in this system does not rely on a gap-opening mechanism at the wall-beam connection interface,eliminating frame expansion effects.The proposed self-centering devices can also be implemented as preassembled links,which facilitates installation and reduces uncertainties associated with the on-site posttensioning procedure.The seismic performance of SC-SP-HCWs is investigated through nonlinear static and incremental dynamic analyses on case study SC-SP-HCWs designed as the lateral load-resisting systems of an eight-story building.The seismic response of the case study SC-SP-HCWs is investigated,considering both local and global engineering demand parameters(EDPs).The results demonstrate the ability of the SC-SP-HCWs to significantly reduce earthquake-induced residual deformations without exacerbating damage to structural ele-ments typically observed in conventional coupled walls. 展开更多
关键词 Hybrid coupled walls Damage-free self-centering links Friction devices Seismic performance Reinforced concrete walls
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Concrete Strength Prediction Using Machine Learning and Somersaulting Spider Optimizer
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作者 Marwa M.Eid Amel Ali Alhussan +2 位作者 Ebrahim A.Mattar Nima Khodadadi El-Sayed M.El-Kenawy 《Computer Modeling in Engineering & Sciences》 2026年第1期465-493,共29页
Accurate prediction of concrete compressive strength is fundamental for optimizing mix designs,improving material utilization,and ensuring structural safety in modern construction.Traditional empirical methods often f... Accurate prediction of concrete compressive strength is fundamental for optimizing mix designs,improving material utilization,and ensuring structural safety in modern construction.Traditional empirical methods often fail to capture the non-linear relationships among concrete constituents,especially with the growing use of supple-mentary cementitious materials and recycled aggregates.This study presents an integrated machine learning framework for concrete strength prediction,combining advanced regression models—namely CatBoost—with metaheuristic optimization algorithms,with a particular focus on the Somersaulting Spider Optimizer(SSO).A comprehensive dataset encompassing diverse mix proportions and material types was used to evaluate baseline machine learning models,including CatBoost,XGBoost,ExtraTrees,and RandomForest.Among these,CatBoost demonstrated superior accuracy across multiple performance metrics.To further enhance predictive capability,several bio-inspired optimizers were employed for hyperparameter tuning.The SSO-CatBoost hybrid achieved the lowest mean squared error and highest correlation coefficients,outperforming other metaheuristic approaches such as Genetic Algorithm,Particle Swarm Optimization,and Grey Wolf Optimizer.Statistical significance was established through Analysis of Variance and Wilcoxon signed-rank testing,confirming the robustness of the optimized models.The proposed methodology not only delivers improved predictive performance but also offers a transparent framework for mix design optimization,supporting data-driven decision making in sustainable and resilient infrastructure development. 展开更多
关键词 concrete strength machine learning CatBoost metaheuristic optimization somersaulting spider optimizer ensemble models
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Numerical Investigation of Porosity and Aggregate Volume Ratio Effects on the Mechanical Behavior of Lightweight Aggregate Concrete
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作者 Safwan Al-sayed Xi Wang +2 位作者 Yijiang Peng Esraa Hyarat Ahmad Ali AlZubi 《Computers, Materials & Continua》 2026年第3期574-602,共29页
In modern construction,Lightweight Aggregate Concrete(LWAC)has been recognized as a vital material of concern because of its unique properties,such as reduced density and improved thermal insulation.Despite the extens... In modern construction,Lightweight Aggregate Concrete(LWAC)has been recognized as a vital material of concern because of its unique properties,such as reduced density and improved thermal insulation.Despite the extensive knowledge regarding its macroscopic properties,there is a wide knowledge gap in understanding the influence of microscale parameters like aggregate porosity and volume ratio on the mechanical response of LWAC.This study aims to bridge this knowledge gap,spurred by the need to enhance the predictability and applicability of LWAC in various construction environments.With the help of advanced numerical methods,including the finite element method and a random circular aggregate model,this study critically evaluates the role played by these microscale factors.We found that an increase in the aggregate porosity from 23.5%to 48.5%leads to a drastic change of weakness from the bonding interface to the aggregate,reducing compressive strength by up to 24.2%and tensile strength by 27.8%.Similarly,the increase in the volume ratio of lightweight aggregate from 25%to 40%leads to a reduction in compressive strength by 13.0%and tensile strength by 9.23%.These results highlight the imperative role of microscale properties on the mechanical properties of LWAC.By supplying precise quantitative details on the effect of porosity and aggregate volume ratio,this research makes significant contributions to construction materials science by providing useful recommendations for the creation and optimization of LWAC with improved performance and sustainability in construction. 展开更多
关键词 Lightweight aggregate concrete aggregate porosity mechanical properties finite element method aggregate volume ratio
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Physics-Informed Surrogate Modelling of Concrete Self-Healing via Coupled FEM-ML with Active Learning
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作者 Ajitanshu Vedrtnam KishorKalauni +2 位作者 Shashikant Chaturvedi Peter Czirak Martin T.Palou 《Computer Modeling in Engineering & Sciences》 2026年第2期316-344,共29页
This study presents a physics-informed modelling framework that combines finite element method(FEM)simulations and supervised machine learning(ML)to predict the self-healing performance of microbial concrete.A FEniCS-... This study presents a physics-informed modelling framework that combines finite element method(FEM)simulations and supervised machine learning(ML)to predict the self-healing performance of microbial concrete.A FEniCS-based FEM platform resolves multiphysics phenomena including nutrient diffusion,microbial CaCO_(3) precipitation,and stiffness recovery.These simulations,together with experimental data,are used to train ML models(Random Forest yielding normalized RMSE≈0.10)capable of predicting performance over a wide range of design parameters.Feature importance analysis identifies curing temperature,calcium carbonate precipitation rate,crack width,bacterial strain,and encapsulation method as the most influential parameters.The coupled FEM-ML approach enables sensitivity analysis,design optimization,and prediction beyond the training dataset(consistently exceeding 90%healing efficiency).Experimental validation confirms model robustness in both crack closure and strength recovery.This FEM–ML pipeline thus offers a generalizable,interpretable,and scalable strategy for the design of intelligent,self-adaptive construction materials. 展开更多
关键词 Self-healing concrete finite element modelling machine learning bio-concrete healing optimization microbial calcium carbonate precipitation
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