Cement & concrete composites最新文献_第7页

Coupled mesoscale analysis of concrete shrinkage 混凝土收缩的耦合中尺度分析

IF 10.8 1区工程技术

Cement & concrete composites Pub Date : 2025-03-06 DOI: 10.1016/j.cemconcomp.2025.106007

Yilin Wang , Giovanni Di Luzio , Jan Vorel , Jan Belis , Xinyan Guo , Roman Wan-Wendner

{"title":"Coupled mesoscale analysis of concrete shrinkage","authors":"Yilin Wang , Giovanni Di Luzio , Jan Vorel , Jan Belis , Xinyan Guo , Roman Wan-Wendner","doi":"10.1016/j.cemconcomp.2025.106007","DOIUrl":"10.1016/j.cemconcomp.2025.106007","url":null,"abstract":"<div><div>Cracking, driven by shrinkage and thermal strains, strongly influences the serviceability and durability of concrete structures. After several decades of use, cracking can cause structural deterioration and damage. Concrete shrinkage is sensitive to temperature and humidity variations in a complex hygrothermal environment. Therefore, an efficient numerical framework is essential to predict the structural response for all potential geometries and environmental conditions. This work presents a new multi-physics simulation framework coupling the mechanical behavior with chemical/physical processes of concrete while considering the meso-structure of concrete. The Lattice Discrete Particle Model (LDPM) is used the describe the mechanical response. The Hygro-Thermo-Chemical (HTC) model, which describes the moisture transport, heat transfer, and curing reaction, is solved using a flow lattice element (FLE) system dual to the mechanical mesh. The development of mechanical characteristics, as well as thermal and hygral eigenstrains owing to continued curing, is driven by the HTC model. In addition, a newly proposed 2-phase formulation for concrete shrinkage is introduced, considering the effect of aggregate volume and stiffness on concrete shrinkage. The results give robust predictions of macroscopic shrinkage for concretes with different mix proportions and indicate a better representation of meso-structural features than the previously proposed 1-phase formulation. To ensure the reliability of the results, five experimental campaigns from the literature were selected to calibrate and validate the numerical model. The model agrees well with the experimental data and offers new insights into local strain distribution and cracking behavior in heterogeneous materials at an acceptable computational cost.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"160 ","pages":"Article 106007"},"PeriodicalIF":10.8,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143560825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Recognition of the free slump in dry concrete mix: A 3D-digital image correlation test and the spatiotemporal variability 干混凝土中自由坍落度的识别：三维数字图像相关测试和时空变异性

IF 10.8 1区工程技术

Cement & concrete composites Pub Date : 2025-03-06 DOI: 10.1016/j.cemconcomp.2025.106012

Yangyi Zhang, Xueshi Liu, Jianyun Wang, Yun Gao

{"title":"Recognition of the free slump in dry concrete mix: A 3D-digital image correlation test and the spatiotemporal variability","authors":"Yangyi Zhang, Xueshi Liu, Jianyun Wang, Yun Gao","doi":"10.1016/j.cemconcomp.2025.106012","DOIUrl":"10.1016/j.cemconcomp.2025.106012","url":null,"abstract":"<div><div>Dry concrete mix has advantages of high construction efficiency and rapid early strength development. It has been employed extensively in a variety of sectors, including construction and pavement engineering. Traditional methods assessing its workability such as the Vebe test are susceptible to human error, which usually leads to the lack of the satisfactory accuracy in practice. To address the limitations of traditional methods, this study develops a three-dimensional digital image correlation (3D-DIC) method to meticulously recognize the free slump in dry concrete mix. Owing to the prominent advances in high precision and full-field measurement, the 3D-DIC method enables a novel monitoring and visualization of the free slump in terms of the spatiotemporal variability, i.e., the temporal evolution and the spatial variability. It is meanwhile possible to elucidate the spatiotemporal variability through two statistical models such as the Gaussian model and the semi variogram exponential model. Consequently, the 3D-DIC method presents two synergistic parameters of high accuracy other than a single one of low accuracy as used in traditional methods to quantify the free slump in dry concrete mix, which correspond respectively to the consistency and cohesiveness of the workability.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"160 ","pages":"Article 106012"},"PeriodicalIF":10.8,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143560824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparison of thermal and mechanochemical activation for enhancing pozzolanic reactivity of illite-rich shale 热活化与机械化学活化增强富伊利石页岩火山灰活性的比较

IF 10.8 1区工程技术

Cement & concrete composites Pub Date : 2025-03-06 DOI: 10.1016/j.cemconcomp.2025.106034

Pengfei Zhao , Alexander Ozersky , Alexander Khomyakov , Karl Peterson

{"title":"Comparison of thermal and mechanochemical activation for enhancing pozzolanic reactivity of illite-rich shale","authors":"Pengfei Zhao , Alexander Ozersky , Alexander Khomyakov , Karl Peterson","doi":"10.1016/j.cemconcomp.2025.106034","DOIUrl":"10.1016/j.cemconcomp.2025.106034","url":null,"abstract":"<div><div>To address the challenges associated with urban construction waste disposal and promote sustainable construction practices, this study investigates the feasibility of repurposing an illite-rich waste shale as a supplementary cementitious material (SCM) through thermal and mechanochemical activation. The aim of this study is to develop a deeper understanding of the relationship between the chemical reactivity of activated shales and the performance of blended cement mortars. Various properties, including phase transitions, particle size distribution, surface morphology, chemical reactivity, as well as mortar fresh properties and compressive strength, were analyzed for the activated shales. The results show that the mechanochemically activated shale exhibited a noticeable increase in pozzolanic reactivity compared to the calcined shale. The mechanochemically activated shale also displayed a more granular surface morphology, which is beneficial for early-age reactivity. A bimodal particle size distribution was observed in the mechanochemically activated shale, likely attributed to the agglomeration of amorphized fine particles. Furthermore, the mechanochemically activated shale had a less negative impact on workability, primarily due to the re-adsorbed surface moisture, which offset the increased water demand in the blended cements. At 20 %, 30 %, and 40 % cement substitution levels, the mechanochemically activated shale mortar mixtures developed compressive strengths comparable to those of the control mixture at both 7 and 28 days. More importantly, the practical significance of this study lies in the successful activation of the illite-rich shale using an attrition mill for the first time, an industrially-scalable milling technology.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"160 ","pages":"Article 106034"},"PeriodicalIF":10.8,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143560827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Active rheology control of cementitious materials containing hard magnetic particles: Sustained response after magnetic intervention 含硬磁颗粒胶凝材料的活性流变控制：磁干预后的持续响应

IF 10.8 1区工程技术

Cement & concrete composites Pub Date : 2025-03-06 DOI: 10.1016/j.cemconcomp.2025.106024

Yiyuan Zhang , Yi Zhang , Yaxin Tao , Xiaodi Dai , Kim Van Tittelboom , Karel Lesage , Geert De Schutter

{"title":"Active rheology control of cementitious materials containing hard magnetic particles: Sustained response after magnetic intervention","authors":"Yiyuan Zhang , Yi Zhang , Yaxin Tao , Xiaodi Dai , Kim Van Tittelboom , Karel Lesage , Geert De Schutter","doi":"10.1016/j.cemconcomp.2025.106024","DOIUrl":"10.1016/j.cemconcomp.2025.106024","url":null,"abstract":"<div><div>The performance of responsive cementitious materials after magnetic intervention plays an important role for the application of active rheology control. For example, during 3D concrete printing, the material needs to sustain the increased rheological properties (e.g. yield stress, etc.) after an intervention in the nozzle to guarantee buildability. This research investigates the use of hard magnetic particles to make sure that the responsive cementitious materials sustain their response after a magnetic intervention. The remanent rheological, microstructural and magnetic properties of responsive cementitious materials after a magnetic intervention were studied. Effects of magnetic flux densities (0 T, 0.3 T, and 0.6 T) and magnetic intervention durations (5 s, 60 s, and 180 s) were investigated and compared. Small amplitude oscillation shear (SAOS) tests were performed to determine the rheological properties including yield stress and structural build-up of responsive cementitious materials. The distribution of hard magnetic particles in the magneto-responsive cementitious materials was investigated by scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDX). The magnetization of magneto-responsive paste was determined by a vibrating sample magnetometry (VSM). A new type of innovative magneto-responsive cementitious materials was developed, which can sustain a significant magneto-rheological response after the intervention of only a few seconds. The degree of response after a magnetic intervention was heavily influenced by the magnetic flux density instead of intervention duration. The remanent alignment and remanent magnetization of magneto-responsive particles in the cementitious materials were verified and confirmed by experimental results.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"160 ","pages":"Article 106024"},"PeriodicalIF":10.8,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143560826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of graphene oxide on resistance of a fly ash-based geopolymer paste to cyclic freeze-thaw damage and post-damage carbonation 氧化石墨烯对粉煤灰基地聚合物浆料抗冻融损伤及损伤后碳化性能的影响

IF 10.8 1区工程技术

Cement & concrete composites Pub Date : 2025-03-05 DOI: 10.1016/j.cemconcomp.2025.106023

Zhipeng Li , Xianming Shi

{"title":"Influence of graphene oxide on resistance of a fly ash-based geopolymer paste to cyclic freeze-thaw damage and post-damage carbonation","authors":"Zhipeng Li , Xianming Shi","doi":"10.1016/j.cemconcomp.2025.106023","DOIUrl":"10.1016/j.cemconcomp.2025.106023","url":null,"abstract":"<div><div>Geopolymer is a sustainable alternative to cement. We employed graphene oxide (GO) to effectively enhance the freeze-thaw (F/T) resistance of an alkali-activated fly ash-based geopolymer (FAGPR) paste. To unravel the beneficial role of GO as an admixture in mitigating the degradation of FAGPR, this study compared the microscopic properties of the original FAGPR paste and its GO-engineered counterpart (GFAGPR) before and after the cyclic F/T process. For these paste samples, their chemical components, microstructure, elemental distribution, chemical bonds, and structure ordering were examined by X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), and Nuclear Magnetic Resonance (NMR), respectively. The experimental results suggest that GO regulated the formation of C-S-H/C-A-S-H gels and improved their polymerization degree by controlling the distribution of key elements. The interaction between Ca cations and negatively charged GO mitigated the leaching of Ca during the F/T process and thus helped the weathered GFAGPR paste maintain higher residual compressive strength and higher polymerization degree.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"160 ","pages":"Article 106023"},"PeriodicalIF":10.8,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143560828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhancing photocatalytic durability of high strength pervious concrete: Micro-mechanical and microscopic mechanisms 提高高强透水混凝土光催化耐久性：微观力学和微观机理

IF 10.8 1区工程技术

Cement & concrete composites Pub Date : 2025-03-05 DOI: 10.1016/j.cemconcomp.2025.106020

Xunli Jiang , Jian-Xin Lu , Xue Luo , Zhen Leng , Chi Sun Poon

{"title":"Enhancing photocatalytic durability of high strength pervious concrete: Micro-mechanical and microscopic mechanisms","authors":"Xunli Jiang , Jian-Xin Lu , Xue Luo , Zhen Leng , Chi Sun Poon","doi":"10.1016/j.cemconcomp.2025.106020","DOIUrl":"10.1016/j.cemconcomp.2025.106020","url":null,"abstract":"<div><div>Nano titanium dioxide (nano-TiO<sub>2</sub>) has been widely used in cement materials to remove nitrogen monoxide (NO), yet the durability of the applied nano-TiO<sub>2</sub> in the cementitious matrix remains a substantial challenge. This study developed a high-strength photocatalytic pervious concrete (HSPPC), and employed a low-pressure cold spraying method to apply the nano-TiO<sub>2</sub> to its surface, aiming to enhance the durability of the photocatalytic coating through synergistic optimization of both the materials and spraying process. The effects of the amount of nano-TiO<sub>2</sub>, spraying methods, and the aggregate-to-binder ratio (A/B) of the previous concrete on NO<sub>x</sub> degradation were determined. Additionally, the interface mechanics and durability enhancement mechanisms of photocatalytic coatings on the HSPPC were revealed through microscale mechanical and microscopic mechanism analyses. The results indicated that the efficiency of NO removal was increased with the increase in the amount of nano-TiO<sub>2</sub>, and A/B ratio. Compared to ordinary pervious concrete, the resistance to seepage scouring and vehicle tire abrasion of HSPPC was significantly improved. Moreover, the combination of HSPPC and the cold spraying method resulted in an efficient synergistic effect, considerably enhancing the durability of the nano-TiO<sub>2</sub> compared to traditional brushing methods. Micromechanical and microstructural analyses revealed that the mesoscopic pore structure formed within the cold-sprayed coating facilitated the formation of hydration products on the HSPPC substrate. This led to the generation of higher polymerization degree of C-S-H gels, which bonded the nano-TiO<sub>2</sub> particles together and enhanced the interfacial bonding with the substrate, effectively improving the cohesion, adhesion, and photocatalytic durability of the nano-TiO<sub>2</sub> coatings.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"160 ","pages":"Article 106020"},"PeriodicalIF":10.8,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143546527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Crack formation and crack width monitoring in cementitious composites with extremely high sensory responses through incorporation of smart PE fibers coated with single-walled carbon nanotubes 采用单壁碳纳米管包覆智能聚乙烯纤维的高感官响应胶凝复合材料中裂缝形成和裂缝宽度的监测

IF 10.8 1区工程技术

Cement & concrete composites Pub Date : 2025-03-05 DOI: 10.1016/j.cemconcomp.2025.106017

Ali Bashiri Rezaie , Marco Liebscher , Golrokh Airom , Mahsa Mohammadi , Peter Machata , Matej Mičušík , Viktor Mechtcherine

{"title":"Crack formation and crack width monitoring in cementitious composites with extremely high sensory responses through incorporation of smart PE fibers coated with single-walled carbon nanotubes","authors":"Ali Bashiri Rezaie , Marco Liebscher , Golrokh Airom , Mahsa Mohammadi , Peter Machata , Matej Mičušík , Viktor Mechtcherine","doi":"10.1016/j.cemconcomp.2025.106017","DOIUrl":"10.1016/j.cemconcomp.2025.106017","url":null,"abstract":"<div><div>To guarantee structural safety, self-sensing concrete has garnered significant attention as an innovative solution for structural health monitoring. In particular, detecting cracks and their widths in concrete structures is an effective strategy for assessing damage conditions and extending service life. In this context, a novel cementitious composite is proposed, demonstrating an exceptional ability to monitor crack formation and width propagation through electrical signals generated by changes in relative electrical resistance (RER) of up to one hundred thousand percent—the highest value reported in the literature to date. Polyethylene (PE) fibers were initially functionalized with tannic acid (TA) and subsequently coated with TA-modified carbon nanotubes (CNTs) to make them electrically conductive for embedding into a normal-strength (NS) concrete matrix. The presence and approximate loading extent of CNTs on the fiber surface were examined using optical and scanning electron microscopes, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis. The resulting CNT-coated fibers exhibited an average resistivity of 5.54 × 10<sup>−5</sup> Ω cm ± 0.19 × 10<sup>−5</sup> Ω cm, indicating excellent electrical conductivity and proper strain-sensing performance. The smart cementitious composites effectively detected crack formation and monitored crack width propagation, as evidenced by a sudden increase in RER (%) and its changes of up to 100,000 %, respectively. These electrical feedback signals were highly distinguishable from other influencing factors, such as weathering conditions, representing a major advancement compared to similar studies.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"160 ","pages":"Article 106017"},"PeriodicalIF":10.8,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143560644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanical properties and its prediction of sulphoaluminate cement-engineered cementitious composites (SAC-ECC) as rapid repair materials applied in winter construction 硫铝酸盐水泥-工程胶凝复合材料（SAC-ECC）作为冬季工程快速修复材料的力学性能及其预测

IF 10.8 1区工程技术

Cement & concrete composites Pub Date : 2025-03-04 DOI: 10.1016/j.cemconcomp.2025.106016

Huayang Sun , Yanlin Huo , Zhichao Xu , Zhitao Chen , Yingzi Yang

{"title":"Mechanical properties and its prediction of sulphoaluminate cement-engineered cementitious composites (SAC-ECC) as rapid repair materials applied in winter construction","authors":"Huayang Sun , Yanlin Huo , Zhichao Xu , Zhitao Chen , Yingzi Yang","doi":"10.1016/j.cemconcomp.2025.106016","DOIUrl":"10.1016/j.cemconcomp.2025.106016","url":null,"abstract":"<div><div>Engineered cementitious composites (ECC) are recognized as effective repair materials. However, Ordinary Portland Cement (OPC)-ECC struggles to meet the demands of emergency repair and construction in cold regions, where rapid strength development is crucial. This paper focuses on the mechanical properties and its prediction model of sulphoaluminate cement (SAC)-ECC under low-temperature curing conditions. The effects of pre-curing times (0.75 h, 1.5 h, 3 h) and curing temperatures (20 °C, 0 °C, −5 °C, −10 °C) on the mechanical properties of ECC were investigated during the early and later stages of low-temperature curing. The results reveal that the compressive and tensile strengths of SAC-ECC decrease significantly with lower curing temperatures and shorter pre-curing times. However, the tensile strain capacity increases under these conditions. Notably, after pre-curing at 20 °C for 3 h followed by curing at −10 °C, the compressive strength reached 30 MPa at 4 h, and the tensile strain capacity exceeded 10 % after 1 day. A physical model based on micromechanical parameters obtained from fracture toughness tests and single-fiber pullout tests was developed, which could simulate and forecast the evolution of tensile properties in SAC-ECC under various curing regimes and ages. The predicted outcomes align well with the experimental results, offering valuable insights for guiding engineering applications in low-temperature environments.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"160 ","pages":"Article 106016"},"PeriodicalIF":10.8,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143538821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Tensile behavior of reinforced UHPC: Effects of autogenous shrinkage and model of tensile capacity via deep learning-based symbolic regression 增强UHPC的拉伸性能：基于深度学习的符号回归模型的自收缩和拉伸能力的影响

IF 10.8 1区工程技术

Cement & concrete composites Pub Date : 2025-03-04 DOI: 10.1016/j.cemconcomp.2025.106019

Lei Tu , Hua Zhao , Chengjun Tan , Junde Hu , Jingqi Cao , Suiwen Wu

{"title":"Tensile behavior of reinforced UHPC: Effects of autogenous shrinkage and model of tensile capacity via deep learning-based symbolic regression","authors":"Lei Tu , Hua Zhao , Chengjun Tan , Junde Hu , Jingqi Cao , Suiwen Wu","doi":"10.1016/j.cemconcomp.2025.106019","DOIUrl":"10.1016/j.cemconcomp.2025.106019","url":null,"abstract":"<div><div>The tensile capacity of reinforced ultra-high performance concrete (R-UHPC) consists of two components: the tensile resistance of steel rebar and the contribution of UHPC. Although previous experimental studies have elucidated the total tensile capacity of R-UHPC, the individual contributions of UHPC and steel rebar remain unclear. Moreover, there is limited research on the influence of autogenous shrinkage on the tensile performance of R-UHPC. Therefore, this study aims to establish a model that accurately quantifies the contributions of both components and investigates the effect of autogenous shrinkage on the tensile behavior of R-UHPC. Direct tensile tests were conducted on both reinforced conventional UHPC (R-CUHPC) and reinforced low-shrinkage UHPC (R-LUHPC) specimens (with the addition of expansive agent and shrinkage-reducing agent) at reinforcement ratios of 1.7 %, 3.0 %, and 6.8 %, respectively. The results indicated that, as the reinforcement ratio increased, the first-cracking strength of R-LUHPC specimens exhibited slight fluctuations, whereas it notably decreased in R-CUHPC specimens. Additionally, autogenous shrinkage had minimal impact on the tensile capacity of R-LUHPC specimens. To tackle the challenge of quantifying the individual contributions of UHPC and steel rebar from experimental data, a deep learning-based symbolic regression method was introduced. As a result, a highly accurate model was developed to calculate the tensile capacity of R-UHPC components, incorporating 1.157 times the steel rebar's yield strength and 0.669 times the UHPC's ultimate tensile strength. Furthermore, this model reflects the load-bearing mechanism in which the steel rebar enters strain-hardening, while the contribution of UHPC does not reach its ultimate tensile strength due to the pull-out of partial steel fibers.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"160 ","pages":"Article 106019"},"PeriodicalIF":10.8,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143538894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exploring the curing regimes for nonhydraulic-hydraulic cementitious material composite binder: Study on the hemihydrate phosphogypsum-ground granulated blast-furnace slag system 非水力-水力胶凝材料复合粘结剂养护体系的探索——半水磷石膏-磨粒化高炉渣体系的研究

IF 10.8 1区工程技术

Cement & concrete composites Pub Date : 2025-03-03 DOI: 10.1016/j.cemconcomp.2025.106018

Zihao Jin, Chuanyu Gong, Xingyang He, Ying Su, Yingbin Wang, Yubo Li, Huahui Qi, Cong Tian

{"title":"Exploring the curing regimes for nonhydraulic-hydraulic cementitious material composite binder: Study on the hemihydrate phosphogypsum-ground granulated blast-furnace slag system","authors":"Zihao Jin, Chuanyu Gong, Xingyang He, Ying Su, Yingbin Wang, Yubo Li, Huahui Qi, Cong Tian","doi":"10.1016/j.cemconcomp.2025.106018","DOIUrl":"10.1016/j.cemconcomp.2025.106018","url":null,"abstract":"<div><div>Beta-hemihydrate phosphogypsum (β-HPG) as a nonhydraulic cementitious material has been extensively utilized to prepare low-carbon building materials. Ground granulated blast-furnace slag (GGBS) shows prospect performance in the modification of β-HPG. However, the strength development of GGBS requires high humidity which is harmful to gypsum-based materials. The influence of various curing regimes on the mechanical strength and microstructure of the β-HPG-GGBS composite binder was studied. Wet curing for 7 d and then dry curing for 21 d (W7d/D21d) proved the best curing conditions. The results show that W7d/D21d has a compressive strength of 22.15 MPa, which is 80 % more than that of dry curing for 28 days (D28d). In addition, the curing condition of W7d/D21d was proved to reduce the pore size and total porosity of the hardened paste, and the large damaged pores of W7d/D21d were decreased by 30 % compared with D28d. This indicates that proper wet curing provides sufficient water for the hardened paste and promotes the hydration degree of the composite binder, improving its mechanical properties. Specifically, the ettringite (AFt) formation of W7d/D21d is 3 times more than that of D28d, resulting in a more compact microstructure. It can be found that the pore structure parameters, compressive strength, total porosity, and fractal dimension of the hardened paste have a high exponential correlation. This paper provides an effective method for using gypsum-based composite binders incorporating hydraulic cementitious materials.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"160 ","pages":"Article 106018"},"PeriodicalIF":10.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143538819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0