Cement & concrete composites最新文献_第7页

The rate-dependent fiber-matrix interface in ultra high-performance fiber reinforced concrete: Interface property determination 超高性能纤维增强混凝土中速率相关纤维-基体界面：界面性能测定

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-12-01 DOI: 10.1016/j.cemconcomp.2025.106423

Ji Woon Park , John E. Bolander , Yun Mook Lim

Quantifying the rate dependency of the fiber-matrix interface is crucial to evaluating the dynamic behavior of fiber-reinforced cementitious composites (FRCCs). Numerous studies have directly conducted high-speed pullout tests on single or multiple fibers. However, current test methods are limited with respect to quantifying the effects of random fiber dispersion, irregular crack surfaces, and the resulting variations in the inclination and embedment length of fibers within FRCC materials. To address these needs, this study uses a novel inverse analysis procedure to accurately capture the dynamic pullout behavior of randomly distributed fibers in composite materials. This has been achieved using a recently developed multi-scale lattice model combined with an optimization algorithm. The numerical model is capable of simulating the mesoscale response of FRCCs while accounting for the rate-dependent fiber-matrix interface at the microscale. The inverse determination of rate-dependent behavior of the reinforcing fibers in strain hardening cementitious composites is consistent with experimental findings. The results provide new insights into the effects of multiple fiber bundling and inclination within the cementitious composite specimens. In particular, the analysis showed that multiple randomly oriented fibers caused more matrix spalling than single-fiber pullout tests, in agreement with experimental observations. Additionally, fiber pullout behavior was governed more by the propagation speed of the dominant crack than by the overall specimen displacement rate.

量化纤维-基体界面的速率依赖关系是评价纤维增强胶凝复合材料动态性能的关键。许多研究直接对单根或多根纤维进行了高速拉拔试验。然而，目前的测试方法在量化纤维随机分散、不规则裂纹表面以及纤维在FRCC材料中倾角和嵌入长度的变化的影响方面是有限的。为了满足这些需求，本研究使用了一种新颖的逆分析程序来准确捕获复合材料中随机分布的纤维的动态拉拔行为。这已经实现了使用最近开发的多尺度晶格模型与优化算法相结合。该数值模型能够模拟纤维碳纤维的中尺度响应，同时在微观尺度上考虑速率相关的纤维-基质界面。应变硬化胶凝复合材料中增强纤维速率依赖行为的逆测定与实验结果一致。研究结果为研究胶凝复合材料试件中多纤维束和倾角的影响提供了新的思路。特别是，分析表明，与单纤维拉拔试验相比，多个随机取向纤维引起的基体剥落更多，这与实验观察结果一致。此外，纤维的拉拔行为更多地受主导裂纹扩展速度的影响，而不是受试件整体位移率的影响。

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引用次数: 0

Local bond-slip behavior and mechanisms of steel fiber-UHPC matrix interface modified by nano-engineering 纳米改性钢纤维- uhpc基体界面的局部粘结滑移行为及机理

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-11-30 DOI: 10.1016/j.cemconcomp.2025.106421

Xinyue Wang , Xinkai Ma , Ashraf Ashour , Linwei Li , Qishuai Wu , Liangsheng Qiu , Baoguo Han

The bond performance at the interface between steel fibers and the ultra-high-performance concrete (UHPC) matrix plays a critical role in determining the mechanical behavior of UHPC. While nano-engineering presents promising strategies to strengthen this interface, the localized bond-slip behavior of steel fibers in nano-engineered UHPC is not fully understood, owing to the complex microstructural features and pronounced stress heterogeneity along the interface resulting from the fiber-matrix modulus disparity. Combining pull-out tests, microstructural characterizations, theoretical modeling, and numerical simulations, this study elucidates two distinct mechanisms responsible for bond enhancement induced by nanofillers: the interface nano-modification effect and the transition zone nano-modification effect. The relative scale between nanofillers and steel fibers governs the enrichment or dilution of nanofillers at the interface, thereby affecting the modification efficacy within the transition zone. These mechanisms collectively contribute to a notable improvement in interfacial bond strength, reaching a peak value of 11.73 MPa—exceeding all previously reported results. The derived bond-slip constitutive models, grounded in these mechanistic insights, indicate that although nano-engineering can substantially improve the strength and durability of UHPC, it also leads to a reduction in ductility.

钢纤维与超高性能混凝土基体界面的粘结性能对超高性能混凝土的力学性能起着至关重要的作用。虽然纳米工程提出了有希望的增强该界面的策略，但由于复杂的微观结构特征和纤维-基质模量差异导致的界面上明显的应力不均匀性，纳米工程UHPC中钢纤维的局部粘结滑移行为尚未完全了解。结合拉出试验、微观结构表征、理论建模和数值模拟，本研究阐明了纳米填料诱导键增强的两种不同机制：界面纳米修饰效应和过渡区纳米修饰效应。纳米填料与钢纤维的相对尺度决定着界面处纳米填料的富集或稀释，从而影响过渡区内纳米填料的改性效果。这些机制共同促进了界面结合强度的显著提高，达到11.73 mpa的峰值，超过了之前报道的所有结果。基于这些力学见解的黏结-滑移本构模型表明，尽管纳米工程可以大大提高UHPC的强度和耐久性，但它也会导致延展性的降低。

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引用次数: 0

Development of ultra-high-performance concrete incorporating nanobubble water and steel slag powder: Mechanical and microstructural optimization 纳米气泡水与钢渣粉混合的高性能混凝土的研制：力学与微观结构优化

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-11-29 DOI: 10.1016/j.cemconcomp.2025.106419

Rongzhen Piao , Hong-Joon Choi , Seong-Jae Kim , Wengui Li , Doo-Yeol Yoo

This study aimed to develop low-carbon sustainable ultra-high-performance concrete (UHPC) by partially replacing ordinary Portland cement with steel slag powder (SSP) and using different types of mixing water—tap water, nanobubble water (NW), and carbon dioxide NW (CNW). NW improved particle dispersion and lubrication, thereby enhancing flowability, whereas CNW slightly reduced flowability owing to localized carbonation and moisture loss. SSP addition improved workability by weakening interparticle van der Waals forces. Both NW and CNW accelerated hydration. CNW also induced in-situ carbonation and generated nanoscale calcium carbonate, thus partially inhibiting C–S–H formation. Fourier transform infrared (FTIR) analysis confirmed an increase in silicate polymerization by CNW and a decrease in hydration products at SSP replacement ≥20 %. NW and CNW improved strength by refining the pore structure and enhancing fiber–matrix bonding. Strength increased at SSP replacement ratios of up to 20 % but decreased at ratios ≥30 % because of insufficient hydration and a weak microstructure. The specimen prepared using CNW and an SSP replacement ratio of 20 % (CNW20) achieved the highest strength, with compressive and tensile strengths 6.2 % and 17.5 % higher than those of the control, respectively. CNW delayed crack initiation and reduced strain localization. Moderate SSP contents (≤20 %) improved crack dispersion by enhancing the integrity of the interfacial transition zone. CNW20 showed optimal cracking resistance, with a 43.5 % higher strain energy density and 18.3 % more microcracks. These findings demonstrate that solid waste utilization can be integrated with in-situ carbon capture to develop ecofriendly UHPC.

本研究旨在通过钢渣粉（SSP）部分替代普通硅酸盐水泥，并使用不同类型的混合水——自来水、纳米泡水（NW）和二氧化碳NW （CNW）——开发低碳可持续高性能混凝土（UHPC）。NW改善了颗粒的分散和润滑，从而增强了流动性，而CNW由于局部碳化和水分损失而略微降低了流动性。SSP的加入通过减弱粒子间范德华力改善了可加工性。NW和CNW都加速了水化。CNW还可以诱导原位碳化，生成纳米级碳酸钙，从而部分抑制C-S-H的形成。傅里叶变换红外（FTIR）分析证实，CNW增加了硅酸盐聚合，当SSP替代量≥20%时，水化产物减少。NW和CNW通过改善孔隙结构和增强纤维-基质结合来提高强度。当SSP替换率达到20%时，强度增加，但当SSP替换率≥30%时，由于水化不足和微观结构薄弱，强度下降。使用CNW和SSP替换率为20% （CNW20）制备的试样强度最高，抗压强度和抗拉强度分别比对照提高8.9%和12%。CNW延迟裂纹萌生，降低应变局部化。适量SSP含量（≤20%）通过增强界面过渡区的完整性来改善裂纹的分散。CNW20的抗裂性能最佳，应变能密度提高43.5%，微裂纹增加18.3%。这些研究结果表明，固体废物利用可以与原位碳捕获相结合，以发展生态友好的UHPC。

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引用次数: 0

Magneto-responsive flow behavior and early-age microstructural evolution of 3D printing lightweight concrete with fly ash cenospheres 3D打印粉煤灰微球轻混凝土的磁响应流动行为及早期微结构演化

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-11-29 DOI: 10.1016/j.cemconcomp.2025.106411

Jielin Tao , Shengming Hu , Zhenhua Duan , Dengwu Jiao

This study develops a magneto-responsive lightweight concrete with fly ash cenospheres (FACs) and micron-sized Fe₃O₄ particles (MPs) to address the critical challenge of balancing extrudability and buildability in 3D concrete printing. By applying controlled magnetic fields synchronized with printing stages, the rheological properties are dynamically adjusted through magnetic particles reorganization. The integrated methodology combines time-dependent rheological tests (including flowability at 0–30 min, shape retention at 20–23 min, and penetration resistance at 30–60 min) with microscale characterization (i.e., XRD, SEM-EDS, and X-CT) and interparticle magnetic force calculation. The results demonstrate that horizontal magnetic field-driven particle rearrangement occurs without chemical phase changes, with the optimal performance at water-to-binder (w/b) ratio of 0.37 where concrete viscosity enables stable magnetic network formation. SEM-EDS and X-CT analyses confirm the alignment of magnetic particles parallel to horizontal magnetic field, correlating with directional strength influence. Additionally, SEM-EDS further reveals preferential MPs accumulation at FACs interfaces after applying long-term horizontal magnetic field for 24 h. Furthermore, this study establishes a fundamental framework for magnetically controllable lightweight concrete, enabling real-time rheology adjustment during 3D printing to achieve adaptive and mechanically robust structures through magnetic-directed microstructural technology. This method can extend the printable time window by leveraging the increasing flowability enhancement effect of MP and resolve the extrudability-buildability conflict by providing high flowability without magnetic field and structural stability under a horizontal magnetic field (achieving an 85.1 % deformation reduction during stacking).

本研究开发了一种具有粉煤灰微球（FACs）和微米级Fe3O4颗粒（MPs）的磁响应轻量化混凝土，以解决3D混凝土打印中平衡可挤压性和可建造性的关键挑战。通过施加与印刷阶段同步的可控磁场，通过磁性颗粒重组来动态调节流变性能。综合方法结合了随时间变化的流变学测试（包括0-30分钟的流动性，20-23分钟的形状保持，30-60分钟的渗透阻力），微观表征（即XRD， SEM-EDS和X-CT）和颗粒间磁力计算。结果表明，水平磁场驱动的颗粒重排发生在没有化学相变化的情况下，当水胶比（w/b）为0.37时，混凝土粘度能够稳定形成磁网，其性能最佳。SEM-EDS和X-CT分析证实磁颗粒的排列平行于水平磁场，与方向强度的影响有关。此外，SEM-EDS进一步揭示了长期水平磁场作用24小时后，在FACs界面上优先积累MPs。此外，本研究建立了磁可控轻质混凝土的基本框架，可以在3D打印过程中实现实时流变调节，通过磁定向微结构技术实现自适应和机械坚固的结构。这种方法可以利用MP增强流动性的效果来延长可打印时间窗口，并通过在无磁场的情况下提供高流动性和水平磁场下的结构稳定性（在堆叠过程中实现85.1%的变形减少）来解决可挤出性与可构建性的冲突。

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引用次数: 0

Elucidating the effect of modulus of sodium silicate on microstructural and mechanical properties of alkali activated slag pastes 研究了水玻璃模量对碱活性矿渣膏微观结构和力学性能的影响

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-11-28 DOI: 10.1016/j.cemconcomp.2025.106415

Dongdong Jiang , Zuhua Zhang , Genshen Li , Caijun Shi

The modulus (Ms) of sodium silicate solution has both qualitative and quantitative effects on the reaction products formed in alkali activated slag (AAS) pastes, primarily consisting of C-(N)-A-S-H gels and hydrotalcite phases. Various intrinsic characteristics of these reaction products exhibit significant variations as a function of Ms, such as the chemistry of both pure phases, as well as the nanostructure and morphology of gel phases. Moreover, the volume fraction of reaction products, identified as the first-order parameter explaining the compressive strength of AAS pastes, is synergistically affected by the reaction degree of slag particles and the solid-phase quantity transformed from soluble silicate species supplied by sodium silicate solution. Specifically, the silicon content supplied by sodium silicate solution at Ms of 2 is comparable to the dissolved silicon content as the reaction degree of slag particles reaches ∼36 %. In addition, the inner products of AAS pastes exhibit superior micromechanical properties, primarily due to the enrichment of hydrotalcite phases rather than contributions from the solid skeleton of gel phases. Their relative proportion within reaction products exerts more significant influence on the compressive strength of AAS pastes than the reaction degree of slag particles.

水玻璃溶液的模量（Ms）对碱活性渣（AAS）膏体（主要由C-(N) a - s - h凝胶和水滑石相组成）形成的反应产物有定性和定量的影响。这些反应产物的各种内在特征表现出显著的变化，如纯相的化学性质，以及凝胶相的纳米结构和形态。反应产物的体积分数作为解释AAS膏体抗压强度的一级参数，受矿渣颗粒的反应程度和由硅酸钠溶液提供的可溶性硅酸盐转化的固相数量的协同影响。具体来说，当渣粒反应程度达到~ 36%时，硅酸钠溶液在Ms = 2时提供的硅含量与溶解硅含量相当。此外，AAS膏体的内部产物表现出优异的微力学性能，这主要是由于水滑石相的富集，而不是凝胶相的固体骨架的贡献。它们在反应产物中的相对比例对AAS膏体抗压强度的影响比对渣粒反应程度的影响更为显著。

{"title":"Elucidating the effect of modulus of sodium silicate on microstructural and mechanical properties of alkali activated slag pastes","authors":"Dongdong Jiang , Zuhua Zhang , Genshen Li , Caijun Shi","doi":"10.1016/j.cemconcomp.2025.106415","DOIUrl":"10.1016/j.cemconcomp.2025.106415","url":null,"abstract":"<div><div>The modulus (Ms) of sodium silicate solution has both qualitative and quantitative effects on the reaction products formed in alkali activated slag (AAS) pastes, primarily consisting of C-(N)-A-S-H gels and hydrotalcite phases. Various intrinsic characteristics of these reaction products exhibit significant variations as a function of Ms, such as the chemistry of both pure phases, as well as the nanostructure and morphology of gel phases. Moreover, the volume fraction of reaction products, identified as the first-order parameter explaining the compressive strength of AAS pastes, is synergistically affected by the reaction degree of slag particles and the solid-phase quantity transformed from soluble silicate species supplied by sodium silicate solution. Specifically, the silicon content supplied by sodium silicate solution at Ms of 2 is comparable to the dissolved silicon content as the reaction degree of slag particles reaches ∼36 %. In addition, the inner products of AAS pastes exhibit superior micromechanical properties, primarily due to the enrichment of hydrotalcite phases rather than contributions from the solid skeleton of gel phases. Their relative proportion within reaction products exerts more significant influence on the compressive strength of AAS pastes than the reaction degree of slag particles.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"166 ","pages":"Article 106415"},"PeriodicalIF":13.1,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145611617","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

Composition-driven microstructure refinement in geopolymers enabled by copper slag-based core-shell structure 铜渣基核壳结构驱动的地聚合物微观结构细化

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-11-28 DOI: 10.1016/j.cemconcomp.2025.106414

Longfei Zhang , Yuxuan Chen , Wenkai Wu , Zhaokang Liu , Qingliang Yu

Geopolymers face limited load-bearing applications due to low elastic modulus and high porosity caused by weak N-A-S-H gels. Traditional modification methods often fail to address interfacial inertness or porosity issues. This study develops a novel copper slag (CS) based core-shell structure featuring an iron-rich core and nano-silica (NS) coating to enhance geopolymer stiffness synergistically. High-purity NS (358 m²/g) synthesized via acid leaching and complexation forms a dense 0.6 μm shell using polyvinylpyrrolidone (PVP). Adding 2 wt% composite optimizes reaction kinetics, increasing 28-day compressive strength by 21.30% (54.3 MPa) and elastic modulus by 26.41% (12.11 GPa), surpassing ordinary Portland cement at equivalent strength. The iron-rich core reduces harmful macro-pores by 8.13%, while the NS shell promotes Al³⁺ substitution for Si⁴⁺, promoting the preferential formation of dense C-A-S-H gels. This dual mechanism achieves high synergy (coefficient = 1.35), enabling advancing sustainable high-performance geopolymers with combined environmental and structural benefits. These findings suggest various promising applications in such as high-rise buildings and large-span bridges.

由于弱N-A-S-H凝胶导致的低弹性模量和高孔隙率，地聚合物的承载应用受到限制。传统的改性方法往往不能解决界面惰性或孔隙度问题。本研究开发了一种新型的铜渣（CS）基核壳结构，该结构具有富铁核和纳米二氧化硅（NS）涂层，以协同提高地聚合物的刚度。采用酸浸法制备高纯度NS (358 m2/g)，并以聚乙烯吡咯烷酮（PVP）络合形成致密的0.6 μm壳层。添加2 wt.%的复合材料优化了反应动力学，28天抗压强度提高了21.30% (54.3 MPa)，弹性模量提高了26.41% (12.11 GPa)，超过了同等强度的普通硅酸盐水泥。富铁核减少了8.13%的有害大孔，而NS壳促进Al3+取代Si4+，促进致密的C-A-S-H凝胶的优先形成。这种双重机制实现了高协同效应（系数= 1.35），使可持续高性能地聚合物具有环境和结构双重效益。这些发现表明了在高层建筑和大跨度桥梁等各种有前景的应用。

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引用次数: 0

Properties and sealing performance of an ultra high-durability cement mortar plug under simulated downhole conditions 模拟井下条件下超高耐久性水泥砂浆桥塞的性能与密封性能

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-11-27 DOI: 10.1016/j.cemconcomp.2025.106417

Ethan Yen, Bora Gencturk, Xiaoying Pan, Huanpeng Hong

Methane leakage from abandoned oil and gas wells is driven by compromised sealing through the cement matrix and at cement–steel and cement–formation interfaces. This study evaluates an ultra high-durability cement mortar plug (UHD-CMP) designed to address the high shrinkage, low tensile strength, and poor interface bonding of conventional mortars under downhole conditions. Compressive strength, shrinkage, porosity, gas permeability, and interface bond strength were measured under five curing regimes simulating thermal and moisture exposures. Three shrinkage-reducing admixtures were assessed: magnesium oxide (MgO), calcium oxide (CaO)-based expansive agent, and a surfactant-based reducer (SRA). UHD-CMP achieved compressive strengths up to 162 MPa, more than twice that of conventional mortars, porosity reductions of up to 71 %, and bulk gas permeability as low as 3.98 × 10⁻²⁰ m², up to five orders of magnitude lower than conventional mortars. Under prolonged moisture exposure at 70 % relative humidity, MgO- and SRA-modified UHD-CMP retained shear bond strengths of 1.5–2.3 MPa and 0.8–1.4 MPa, respectively, compared to 0.2 MPa or less for conventional mortars. Normal tensile bond strength was also significantly higher, with UHD-CMP maintaining approximately 0.44–0.46 MPa versus 0.09–0.11 MPa for conventional mortars under the same conditions. At elevated temperatures of 50–80 °C and 50 % relative humidity, shear bond strength decreased compared to standard curing but remained substantially higher than that of conventional mortars, which failed at 0.2 MPa or less. These results demonstrate UHD-CMP's potential for long-term sealing durability in well abandonment applications.

废弃油气井的甲烷泄漏是由于水泥基质、水泥-钢和水泥-地层界面的密封受损造成的。该研究评估了一种超高耐久性水泥砂浆桥塞（UHD-CMP），该桥塞旨在解决常规砂浆在井下条件下的高收缩率、低抗拉强度和界面粘结性差的问题。抗压强度、收缩率、孔隙率、透气性和界面粘结强度在模拟热和湿暴露的五种固化制度下进行了测量。评估了三种减少收缩的外加剂：氧化镁（MgO）、氧化钙（CaO）基膨胀剂和表面活性剂基还原剂（SRA）。UHD-CMP的抗压强度高达162 MPa，是传统砂浆的两倍多，孔隙率降低高达71%，整体渗透率低至3.98 × 10-20 m2，比传统砂浆低5个数量级。在70%的相对湿度下，MgO和sra改性的UHD-CMP分别保持了1.5-2.3 MPa和0.8-1.4 MPa的剪切强度，而传统砂浆的剪切强度为0.2 MPa或更低。UHD-CMP的正常抗拉强度也显著提高，在相同条件下，UHD-CMP的抗拉强度约为0.44-0.46 MPa，而传统砂浆的抗拉强度为0.09-0.11 MPa。在50-80°C和50%相对湿度的高温下，与标准养护相比，抗剪粘结强度有所下降，但仍远高于传统砂浆，后者在0.2 MPa或更低的温度下失效。这些结果表明，UHD-CMP在弃井应用中具有长期密封耐久性的潜力。

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引用次数: 0

Unraveling the multiscale enhancement mechanism of nano-Al2O3 on subzero-prepared alkali-activated slag paste 揭示了纳米al2o3在亚零制备碱活性矿渣膏体上的多尺度强化机理

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-11-26 DOI: 10.1016/j.cemconcomp.2025.106418

Jin Xu, Hongen Zhang, Qiang Ren, Wenting Li, Bei He, Zhengwu Jiang

Alkali-activated materials show promise for in-situ subzero preparation due to alkaline activators' lower freezing point. Nanomaterials offer potential to enhance mechanical performance, but their enhancement mechanisms under subzero require deeper systematic exploration. This study investigated the performance of alkali-activated slag paste (AASP) prepared in-situ over 20 °C to −20 °C and explored the modification mechanisms of nano-Al₂O₃ (NA) under subzero temperatures with MIP, TGA, SEM-EDS, and ²⁹Si NMR technologies. The study showed that the compressive strength of AASP significantly weakened, closely associated with the reduction in C-A-S-H content and the decline in polycondensation degree as the reaction temperature decreased. Furthermore, the pore structure deteriorated and carbonation intensified. NA had high reactivity, could provide additional aluminum phase through pozzolanic reaction, and also had a nucleation effect. AASP improved the production of C-A-S-H through the coupling of the above effects at the early stage of product formation. Appropriate NA of 0.5 wt% facilitated the formation and polycondensation of C-A-S-H and optimized the pore distribution, but excessive addition led to an increased proportion of large and harmful pores, primarily due to agglomeration effects. This study clarified the deterioration mechanisms of subzero-prepared AASP and the multiscale enhancement strategies using nanomaterials, establishing reaction process models that offer critical insights for engineering applications in cold climates.

由于碱性活化剂的冰点较低，碱活化材料有望在低温原位制备。纳米材料具有提高机械性能的潜力，但其在低温条件下的增强机制需要更深入的系统探索。本研究考察了在20℃~ -20℃条件下原位制备的碱活性矿渣膏体（AASP）的性能，并利用MIP、TGA、SEM-EDS和29Si NMR等技术探讨了纳米al2o3 （NA）在零下温度下的改性机理。研究表明，AASP的抗压强度明显减弱，这与随着反应温度的降低，C-A-S-H含量的降低和缩聚度的下降密切相关。孔隙结构恶化，碳酸化加剧。NA具有较高的反应活性，可以通过火山灰反应提供额外的铝相，并具有成核作用。在产物形成初期，AASP通过上述效应的耦合提高了C-A-S-H的产量。适量添加0.5 wt.%的NA有利于C-A-S-H的形成和缩聚，优化了孔的分布，但过量添加会导致大孔和有害孔的比例增加，这主要是由于团聚效应。本研究阐明了亚零度制备的AASP的劣化机制和使用纳米材料的多尺度增强策略，建立了反应过程模型，为寒冷气候下的工程应用提供了重要见解。

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引用次数: 0

Insight into a novel polycarboxylate superplasticizer with crack resistance for cement-based materials: synthesis, performance and mechanisms 一种新型抗裂聚羧酸型水泥基材料减水剂：合成、性能和机理

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-11-26 DOI: 10.1016/j.cemconcomp.2025.106413

Kai Ma , Wenhao Luo , Yali Li , Xingyu Gan , Lingchao Lu , Laibo Li

The inevitable volume shrinkage of concrete during the hardening process can lead to the formation of cracks. The existence of cracks can significantly reduce the mechanical properties and durability of concrete. A novel polycarboxylate superplasticizer (NPM) with crack resistance was designed to improve the crack resistance of cement-based materials by regulating the molecular structure of polycarboxylate superplasticizers. The structure, molecular weight and reaction degree of NPM were precisely determined. The effect of NPM on the mechanical performance of cement-based materials has been comprehensively analyzed. The results revealed that the NPM can reduce the peak heat release of cement hydration and increase the cumulative heat of cement hydration. The autogenous shrinkage, drying shrinkage, cracking index and harmful pores of the sample were decreased by 87.0 %, 48.83 %, 51.80 %, and 27.21 %, respectively. The improved crack resistance can be attributed to the introduction of amphiphilic groups, which effectively reduce surface tension and capillary stress within the pore solution, thereby mitigating the shrinkage and cracking behaviour of the cement-based materials.

混凝土在硬化过程中不可避免的体积收缩会导致裂缝的形成。裂缝的存在会显著降低混凝土的力学性能和耐久性。设计了一种新型抗裂聚羧酸酯型高效减水剂（NPM），通过调节聚羧酸酯型高效减水剂的分子结构来提高水泥基材料的抗裂性能。精确测定了NPM的结构、分子量和反应度。综合分析了NPM对水泥基材料力学性能的影响。结果表明：NPM能降低水泥水化峰值放热，增加水泥水化积热；试样的自收缩率、干收缩率、开裂指数和有害孔隙率分别降低了87.0%、48.83%、51.80%和27.21%。抗裂性能的提高可归因于两亲性基团的引入，这有效地降低了孔隙溶液中的表面张力和毛细应力，从而减轻了水泥基材料的收缩和开裂行为。

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引用次数: 0

Alkali-activated metakaolin geopolymers as structural electrolytes: Insights into structure–function relationships and energy storage potential 碱活化偏高岭土聚合物作为结构电解质：结构-功能关系和储能潜力的见解

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-11-26 DOI: 10.1016/j.cemconcomp.2025.106407

Jiaxi Mao , Suxi Wang , Wentao Jia , Yi Liu , Shikun Chen , Yajun Zhang , Dongming Yan

The rapid growth of distributed and renewable energy systems has created an urgent demand for structural materials capable of simultaneously providing mechanical support and energy‐storage functionality. Conventional cementitious materials, however, exhibit low ionic conductivity and poor electrochemical activity, limiting their use in multifunctional energy‐storage structures. To address this challenge, this study explores the development of alkali‐activated metakaolin (MK) geopolymers modified with different sodium salts (Na₂SO₄, NaCl, and NaOH) as structural solid electrolytes. The incorporation of sodium salts enhanced the ionic conductivity and capacitive behavior of the MK‐based electrolytes. Results showed that the incorporation of sodium salts significantly enhanced the ionic conductivity and capacitive performance of the geopolymer electrolytes. The Na₂SO₄‐modified sample (MK‐S) exhibited the highest ionic conductivity of 33.22 mS cm⁻¹ and an areal capacitance of 603.93 mF cm⁻², corresponding to a 4.5‐fold increase over unmodified MK. This improvement is primarily associated with enhanced Na ⁺ availability and refined pore connectivity attributed to the presence of SO₄²⁻ anions. These findings demonstrate a viable route toward structural electrolytes for next‐generation energy‐storage‐integrated building materials, although further investigation under application scenarios is still required.

在胶凝材料中集成机械稳健性和离子电导率代表了一种有前途的策略，即用于储能集成建筑系统的多功能结构电解质。在这项研究中，用不同的钠盐（Na2SO4， NaCl和NaOH）修饰碱活化的偏高岭土（MK）地聚合物，以阐明凝胶结构演变，离子传输行为和电化学性能之间的关系。结果表明，钠盐的掺入显著提高了地聚合物电解质的离子电导率和电容性能。Na2SO4修饰样品（MK‐S）的离子电导率最高，为33.22 mS cm-1，面电容为603.93 mF cm-2，比未修饰的MK增加了4.5倍。这种改善是由于SO42-配位诱导的移动Na+浓度增加和优化的孔连性的协同作用。这些发现为下一代储能集成建筑材料提供了一条通向耐用结构固体电解质的可行途径。

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