Cement & concrete composites最新文献

{"title":"Quantitative analysis of pore structures and microcracks in self-healing concrete after freeze-thaw exposure: An X-ray computed tomography-based approach","authors":"Jialuo He ,&nbsp;Yong Deng ,&nbsp;Xianming Shi","doi":"10.1016/j.cemconcomp.2025.106105","DOIUrl":"10.1016/j.cemconcomp.2025.106105","url":null,"abstract":"<div><div>X-ray computed tomography (CT) is a valuable tool for investigating the microstructure of concrete. This study introduces a method for analyzing the pore structures and microcracks of self-healing concrete after 300 rapid freeze/thaw (F/T) cycles using CT images with a relatively low resolution of 18.08 μm. Urea-formaldehyde microcapsules alone and in combination with polyvinyl alcohol microfibers were able to reduce 39.1 % and 65.5 % of the microcracks, respectively. Our approach involves calculating the total porosity and identifying constituents within the damaged pore structure based on geometric characteristics, employing the concepts of both circularity and roundness to discriminate intact pores, microcracks, and small/large-size pores with microcracks. The method's reliability is validated by comparing the total porosity results with the mercury intrusion porosimetry data. Our approach provides an effective tool for quantitative evaluation of the microstructure of self-healing concrete after freeze-thaw exposure, paving the way for more efficient and cost-effective analyses of concrete durability.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"162 ","pages":"Article 106105"},"PeriodicalIF":10.8,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143909912","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}

{"title":"Investigation of fracture property of the fiber-reinforced cementitious composites casted using a novel fiber orientation method","authors":"Honglei Chang ,&nbsp;Zihang Kong ,&nbsp;Shuyuan Fan ,&nbsp;Yuxi Cai ,&nbsp;Feng Guo ,&nbsp;Qianping Ran ,&nbsp;Hongzhi Zhang ,&nbsp;Pan Feng","doi":"10.1016/j.cemconcomp.2025.106111","DOIUrl":"10.1016/j.cemconcomp.2025.106111","url":null,"abstract":"<div><div>Fiber-reinforced cementitious composites (FRCC) exhibit enhanced mechanical properties when fibers are uniformly dispersed and aligned parallel to the principal stress direction. This study introduces a novel fiber-ball vibration method to improve fiber orientation in FRCC. The fracture performance of FRCC prepared with this method was evaluated, and the fiber distribution within the matrix was analyzed in relation to the fiber orientation factor and fracture performance. Additionally, the interfacial transition zone (ITZ) between the fiber-balls and the paste was characterized, revealing the mechanisms through which the fiber-ball vibration method influences FRCC fracture performance. Experimental results indicate that the fiber-ball vibration method causes fibers to align more effectively, resulting in a 62.5 % increase in the fiber orientation factor along the principal stress direction compared to conventional mixing techniques. FRCC produced by this method demonstrates enhanced fracture performance, with a 26.2 % increase in initial crack toughness over plain cement mortar and a 29.8 % increase over FRCC fabricated using the conventional mixing method. Furthermore, unstable fracture toughness and fracture energy increased by 40 % and 470 %, respectively, compared to plain cement mortar, although these enhancements remained lower than those achieved with conventional mixing. The disparity is primarily attributed to the wider ITZ and lower elastic modulus between fiber-balls and paste, stemming from the negative effects of clustering of fibers and the smooth surface of steel balls, which increase the internal vulnerability in internal regions of FRCC. Nevertheless, the fiber-ball vibration method offers a promising approach for orienting fibers in FRCC. With further refinement, this method could achieve even greater toughening effects by optimizing the distribution of fibers along the principal stress direction.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"161 ","pages":"Article 106111"},"PeriodicalIF":10.8,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143909838","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}

{"title":"High early strength alkali-activated mortar from artificial slag blended with high-volume limestone powder: Reaction kinetics and thermodynamic modeling","authors":"Hamdy A. Abdel-Gawwad ,&nbsp;Tamino Hirsch ,&nbsp;Christian Lehmann ,&nbsp;Dietmar Stephan","doi":"10.1016/j.cemconcomp.2025.106108","DOIUrl":"10.1016/j.cemconcomp.2025.106108","url":null,"abstract":"<div><div>The European Unions goal of climate neutrality by 2050 and the associated switch in pig iron production from the CO₂-intensive blast furnace process to the direct reduction process means that blast furnace slag is becoming increasingly scarce and will no longer be available in some regions in the foreseeable future. This applies to its use in classic cements as well as in alkali-activated binders. This study explores a new type of artificial slag (AS), with adapted chemical and physical properties, as an alternative to traditional BFS. Thanks to the adapted chemical and physical performance of AS, it exhibits exceptional reactivity, achieving high mechanical performance even when a significant portion is replaced with a widely available and inexpensive filler. Replacing a high volume of AS (≥70 vol%) with limestone powder (LP) in the alkali-activated system results in the formation of a hardened material with high early strength. The mortar composed of a 30–70 AS-LP volume ratio and activated with sodium silicate at a Na₂O equivalent of 5 wt% by weight of all powder exhibited the highest 2-, 28- and 90-day strengths of 67.8 MPa, 81.7 MPa, and 82.4 MPa, respectively. However, decreasing Na₂O equivalent to 3 wt% results in a comparable 90-day strength value. GEMS modeling revealed that the LP-AS content, as well as the source and dosage of Na₂O, significantly influenced the type and quantity of activation products. Furthermore, the results demonstrated that LP promotes the formation of activation products, while quartz powder had no appreciable effect.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"161 ","pages":"Article 106108"},"PeriodicalIF":10.8,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143907679","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}

{"title":"Exploring a feasible inhibitor-coating protective system for corrosion protection of steel in mortar","authors":"Yongqi Liu ,&nbsp;Jinjie Shi","doi":"10.1016/j.cemconcomp.2025.106109","DOIUrl":"10.1016/j.cemconcomp.2025.106109","url":null,"abstract":"<div><div>This study aims to reduce the adverse effects of corrosion inhibitors on mortar performance while improving the corrosion resistance of steel in mortar exposed to chloride-bearing aggressive environments. To achieve this target, a novel inhibitor-coating protective system was designed, consisting of an admixed phytate corrosion inhibitor in mortar and a phytate-based smart protective coating on steel. The protective system operates through a synergistic inhibition mechanism, where phytate ions adsorb on the damaged regions of coating and interact with molybdate ions released from the coating to form a multilayer protective film, thereby significantly enhancing the corrosion resistance of steel. Moreover, the addition of phytate had no obvious impact on the mechanical properties of mortar, while the formed phytate-based complexes positively contributed to the mortar compactness by filling the pores and defects, providing additional corrosion protection against chloride attack for the embedded steel.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"161 ","pages":"Article 106109"},"PeriodicalIF":10.8,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143898094","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}

{"title":"A novel expansion-tolerant strategy to improve the sulfate resistance of cementitious materials: Guided formation of CaSO4 within superabsorbent polymers (SAPs) pores","authors":"Han Wang ,&nbsp;Tongning Cao ,&nbsp;Junlin Lin ,&nbsp;Yali Li ,&nbsp;Guoxing Sun ,&nbsp;Zeyu Lu ,&nbsp;Jinyang Jiang","doi":"10.1016/j.cemconcomp.2025.106107","DOIUrl":"10.1016/j.cemconcomp.2025.106107","url":null,"abstract":"<div><div>During the sulfate attack process, the expansion of CaSO₄ formation in dense cement matrix resulted in the mechanical deterioration of cementitious materials. In this research, a novel expansion-tolerant strategy was proposed to mitigate the expansion pressure by guiding the formation of CaSO₄ within the preset pores introduced by superabsorbent polymers (SAPs). The experimental results showed that the compressive strength of cement paste (C₃A content: 5.61 <em>wt</em>%) with 0.1 <em>wt</em>% addition of SAPs can be sustained after 240 d of sulfate attack, whereas the one without SAPs showed a 21 % reduction with obvious surface spalling and cracking. In addition, the numerical simulation results indicated that the expansion pressure of CaSO₄ formation was correspondingly reduced by 41 %, which beneficially increased the sulfate resistance of cement paste by 170 %. Such a remarkable enhancement was built on the enrichment of Ca(OH)₂ within SAPs pores, which were previously dispersed randomly throughout the cement matrix. During the sulfate attack, sufficient Ca²⁺ provided by Ca(OH)₂ facilitated the in-situ formation of CaSO₄ in micro-scaled SAPs pores, which offered space for accommodating the CaSO₄ crystallization therefore reducing the expansion pressure. In conclusion, the current study presents a novel strategy to guide the formation of CaSO₄ in SAPs pores, effectively mitigating expansion-related damage and opening new frontiers for improving the sulfate resistance of cementitious materials.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"161 ","pages":"Article 106107"},"PeriodicalIF":10.8,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143889995","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}

{"title":"Advanced industrial-grade carbon-fiber-reinforced geopolymer cement supercapacitors for building-integrated energy storage solutions","authors":"Ji-Hua Zhu,&nbsp;Xiangfei Wang,&nbsp;Hongtao Yu,&nbsp;Shuxia Liu,&nbsp;Chun Pei,&nbsp;Feng Xing","doi":"10.1016/j.cemconcomp.2025.106106","DOIUrl":"10.1016/j.cemconcomp.2025.106106","url":null,"abstract":"<div><div>The integration of energy storage capabilities into building materials represents a revolutionary advancement in sustainable energy solutions. This study introduces and explores a carbon-fiber-reinforced cementitious supercapacitor, marking a pioneering step in leveraging construction materials for dual structural and energy storage purposes. Employing geopolymer cement (GC) as a solid electrolyte and polyacrylonitrile (PAN)-based carbon fibers (CFs) as electrode materials, this novel supercapacitor exhibited electrochemical properties superior to those of conventional building materials. Electrochemical modification of CFs proved to be effective in significantly enhancing the performance of the cement-based supercapacitor, with the areal capacitance increasing from 1.6 mF cm⁻² to an impressive 86 mF cm⁻². The optimized supercapacitor achieved remarkable energy and power densities of 17.2 μWh cm⁻² and 600 μW cm⁻², respectively, at a current density of 1 mA cm⁻². The energy density achieved is comparable to that of cement-based batteries. This innovative approach to supercapacitor fabrication not only validates the potential of supercapacitor technology in augmenting the energy storage capabilities of buildings but also enhances the multifunctionality of carbon-fiber-reinforced cementitious materials. Our findings herald a new era in sustainable construction in which structural integrity and energy efficiency will coalesce, paving the way for the next generation of smart energy-resilient infrastructures.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"161 ","pages":"Article 106106"},"PeriodicalIF":10.8,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143889996","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}

{"title":"Advanced 3D-Printed auxetic structures: Mechanical performance evaluation of ECC in rotating rigid configurations","authors":"Peiying Wang ,&nbsp;Xing Ren ,&nbsp;Jing Zhang ,&nbsp;Panpan Zhu ,&nbsp;Jia Kang ,&nbsp;Jiajia Zhou ,&nbsp;Zhanqi Cheng ,&nbsp;Hu Feng","doi":"10.1016/j.cemconcomp.2025.106101","DOIUrl":"10.1016/j.cemconcomp.2025.106101","url":null,"abstract":"<div><div>This study investigated mechanical properties, including the negative Poisson's ratio (NPR) effect and energy absorption capacity, of single-cell unit rotation rigid body (SCRR) structures fabricated using 3D-printed engineering cementitious composites (ECC). Printable ECC mixtures were optimised for extrudability, buildability, and workability, achieving a compressive strength exceeding 40 MPa, tensile strain capacity above 4 %, and fracture toughness higher than <span><math><mrow><mn>2</mn><mspace></mspace><mtext>MPa</mtext><mo>·</mo><msup><mi>m</mi><mfrac><mn>1</mn><mn>2</mn></mfrac></msup></mrow></math></span>. Models of cast SCRR structures and optimal printed paths were designed. Both the cast and printed SCRR specimens underwent uniaxial compression tests and were monitored using digital image correlation (DIC) technology. The compression curves from the experiments and ABAQUS simulations revealed three distinct deformation stages: elastic (<em>Stage I</em>), rotation (<em>Stage II</em>), and densification (<em>Stage III</em>). As the rotational angle (α) increased, <em>Stage II</em> expanded significantly, enhancing the energy absorption capacity. Specifically, the energy absorption (<em>SEA</em>) increased from 520.816 kJ/m³ at α = 30° to 880.314 kJ/m³ at α = 60°, whereas the compression force efficiency (<em>CFE</em>) was stable between 45° and 60°, demonstrating consistent performance. The anisotropy induced by printing in the specified direction facilitated fibre alignment at the SCRR joints, resulting in improved ductility and stress performance compared with cast specimens. Through this series of experiments, optimal SCRR design dimensions were proposed, confirming the potential of ECC-based SCRR structures to achieve auxetic behaviour. This study lays a foundation for the application of rigid rotational bodies in construction, offering insights into lightweight design and energy-absorption optimisation for building systems.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"161 ","pages":"Article 106101"},"PeriodicalIF":10.8,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143881860","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}

{"title":"Rapid visualization and quantification of water penetration into cement paste using near-infrared hyperspectral imaging","authors":"Shiyuan Li ,&nbsp;Yuya Sakai","doi":"10.1016/j.cemconcomp.2025.106103","DOIUrl":"10.1016/j.cemconcomp.2025.106103","url":null,"abstract":"<div><div>Water penetration is the leading cause of durability deterioration of cementitious materials, and the rapid in-situ visualization and quantification of water penetration process is important for evaluating water absorption behavior and durability of material. This study proposed a novel method to rapidly visualize and quantify the water penetration into cementitious materials using near-infrared hyperspectral imaging. Specifically, three different areas were distinguished as the dry area, the transition area (including wetting front) and completely wet area during the water absorption process based on the reflectance gradient of cement paste. A strong linear relationship between reflectance and water content was established through slice weighing calibration, enabling accurate quantification of water absorption. The real-time tracking of the water content distribution and penetration depth evolution was realized. Furthermore, the study revealed that water absorption behavior is significantly governed by local pore structure, and momentum balance of capillary water absorption behavior in porous media was used to explain the dynamic water transport mechanisms. Compared to traditional visualization techniques, the proposed method has achieved a millisecond-level breakthrough in time. This study provides an efficient and practical reference for on-site in-situ quantitative evaluation of cementitious engineering structures.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"161 ","pages":"Article 106103"},"PeriodicalIF":10.8,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880841","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}

{"title":"Assessment of particle packing approach for design of low-clinker, LC3 binders at low water-to-solids ratio","authors":"Connor Szeto ,&nbsp;Qingxu Jin ,&nbsp;Franco Zunino ,&nbsp;Kimberly E. Kurtis","doi":"10.1016/j.cemconcomp.2025.106104","DOIUrl":"10.1016/j.cemconcomp.2025.106104","url":null,"abstract":"<div><div>Limestone calcined clay cements (LC3) are a promising class of low-clinker cementitious binders. While LC3 concrete is typically formulated with a water-to-solid (w/s) ratio of 0.40 or higher, more recent research has explored using a low w/s ratio. Many advanced cementitious systems like ultra-high-performance concrete (UHPC) and engineered cementitious composites (ECC) require lower w/s for optimal performance. This study explores the hydration and strength development of LC3-based binders with a lower w/s ratio using particle packing approach as a design guide. Hydration was assessed through isothermal calorimetry, thermogravimetric analysis, and X-ray diffraction. The results show strong correlations between compressive strength and the initial particle packing index (PPI), particularly at early ages up to 7 days when physical effects are more influential. Additionally, an Environmental Performance Indicator (EPi) revealed a high correlation between PPI and the environmental efficiency of the mixtures. However, these correlations diminish at later ages as the differences in hydration kinetics and products that alter the microstructure become more significant. The presence of unhydrated cement grains after 90 days highlights incomplete hydration at low w/s ratios. In addition, the results show that while the inclusion of the fly ash did improve hydration of the system, the full benefit from the pozzolanic reactions may not be realized at the low w/s examined here. These findings demonstrate the potential of using particle packing to design LC3 with low w/s ratios, particularly for predicting early strength, while addressing factors that affect long term performance.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"161 ","pages":"Article 106104"},"PeriodicalIF":10.8,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143889997","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}

{"title":"On the evolution of cement sheath stress in wells during curing","authors":"Anisa Noor Corina,&nbsp;Al Moghadam","doi":"10.1016/j.cemconcomp.2025.106102","DOIUrl":"10.1016/j.cemconcomp.2025.106102","url":null,"abstract":"<div><div>Portland Cement in the well construction provides zonal isolation, preventing unwanted fluid migration to shallow aquifers or the surface. Despite its widespread application for well sealing, the evolution of cement sheath stress state during curing is not well-known. The radial stress in the cement sheath is the key parameter behind the formation of microannuli, a continuous fracture-like feature at the cement sheath's interface that can become a leakage pathway. In this work, we developed an experimental setup to measure the evolution of stress and pore pressure of a cement sheath. The experiments simulate a cement sheath placed next to an impermeable formation, such as a caprock. Two different axial boundary conditions of plane stress and plane strain were considered. The results show that pore pressure loss due to water consumption by cement clinker hydration occurs at a faster rate for the plane strain condition than the plane stress. Due to the poromechanical properties of cement, the drop in pore pressure also reduces the stress at the inner and outer interfaces of a cement sheath. An analytical model is proposed to confirm the stress evolution and to explain the influence of the formation stiffness on the stress drop. The impact of hydration on cement stress is significant and must be taken into account in well integrity and leakage assessment studies.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"162 ","pages":"Article 106102"},"PeriodicalIF":10.8,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862458","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}