Construction and Building Materials最新文献_第5页

Super absorbent polymer-modified coconut fiber (SMCF): Its preparation, microstructure and effect on cement mortar strength and shrinkage properties 高吸水性聚合物改性椰子纤维（SMCF）的制备、微观结构及其对水泥砂浆强度和收缩性能的影响

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145261

Yong Yu , Rui Meng , Zuquan Jin , Xiaoying Zhang

The internal moisture loss caused by the combined effects of early-age hydration and evaporation after concrete construction induces shrinkage deformation, which ultimately results in cracking when the deformation exceeds the ultimate tensile strain of concrete. Therefore, enhancing the tensile strength of concrete and reducing its shrinkage are key to controlling the risk of cracking. To mitigate these issues, a novel composite material was developed in this study by modifying coconut fibers with a superabsorbent polymer (SAP). The coconut fibres serve to enhance the tensile strength of concrete and sequester carbon dioxide absorbed via photosynthesis, while also contributing to internal curing. Whereas, the SAP functions by releasing moisture during the concrete's drying phase to mitigate water loss, thereby effectively reducing drying shrinkage. The microstructure and chemical bonding of the Super Absorbent Polymer-Modified Coconut Fiber (SMCF) were examined by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Thermogravimetric analysis (TGA). The distribution of the fibers within the cementitious matrix was observed using X-ray computed tomography (CT); their impact on the internal pore structure was evaluated by low-field nuclear magnetic resonance (NMR) spectroscopy. Additionally, mechanical and shrinkage properties were tested for cement mortars incorporating SMCF. The results indicate the superabsorbent polymer (SAP) was successfully loaded into the porous coconut fibers, forming new chemical bonds. The electrostatic repulsion generated by the SAP enhanced fiber dispersion, which in turn optimized the pore structure by increasing gel and transition pores and reducing total porosity, as evidenced by NMR. Consequently, at a 0.343 % SMCF dosage, the cementitious composite exhibits a 4.6 % increase in flexural strength, a 19.8 % increase in compressive strength, and a 12.23 % reduction in drying shrinkage.

混凝土施工后早期水化和蒸发共同作用造成的内部水分损失引起收缩变形，当变形超过混凝土的极限拉伸应变时，最终导致开裂。因此，提高混凝土抗拉强度，减小混凝土收缩是控制混凝土开裂风险的关键。为了减轻这些问题，本研究通过用高吸水性聚合物（SAP）修饰椰子纤维开发了一种新型复合材料。椰子纤维有助于提高混凝土的抗拉强度，并通过光合作用吸收二氧化碳，同时也有助于内部固化。然而，SAP通过在混凝土干燥阶段释放水分来减轻水分损失，从而有效地减少干燥收缩。采用扫描电子显微镜（SEM）、傅里叶红外光谱（FTIR）和热重分析（TGA）对高吸水性聚合物改性椰子纤维（SMCF）的微观结构和化学键进行了表征。利用x射线计算机断层扫描（CT）观察纤维在胶凝基质中的分布；采用低场核磁共振（NMR）技术评价了它们对孔隙内部结构的影响。此外，还测试了含SMCF的水泥砂浆的力学性能和收缩性能。结果表明，高吸水性聚合物（SAP）成功地加载到多孔椰子纤维中，形成了新的化学键。核磁共振表明，SAP产生的静电斥力增强了纤维的分散性，从而通过增加凝胶孔和过渡孔以及降低总孔隙率来优化孔隙结构。因此，当SMCF添加量为0.343 %时，胶凝复合材料的抗弯强度提高了4.6 %，抗压强度提高了19.8 %，干燥收缩率降低了12.23 %。

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引用次数: 0

Experimental study on hydrogen permeation in concrete and microscopic mechanisms 混凝土中氢渗透试验研究及微观机理

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145257

Haodong Sun , Jian Jiang , Zhiwei Cang , Wei Chen , Jihong Ye

Concrete serves as a crucial material for underground hydrogen storage, and its permeability directly influences the safety of storage installations. Existing research has primarily focused on the permeability of admixtures and macroscopic permeability, which fails to reflect complex multiphase permeability characteristics. In this study, hydrogen permeability experiments are conducted in concrete specimens considering the effect of water-to-cement ratios and aggregate volumes. A 3D mesoscopic finite element model is constructed using the “COMSOL with MATLAB” methodology through which parametric analyses are performed. The SEM and CT tests are conducted to investigate the microstructure of specimens and provide basis for mesoscopic modelling. A prediction model of concrete permeability coefficients is established, and an optimized mix-proportion design of low-permeability concrete is proposed. The experimental results show that both the water-to-cement ratio and aggregate volume fraction significantly influence permeability. An increase of 0.1 in the ratio may lead to an increase of 2–3 times in the mortar permeability coefficient, whereas a 10% increase in the aggregate volume fraction can reduce the concrete permeability coefficient by approximately 10%. The simulation results reveal that the seepage field of concrete is nonhomogeneous and exhibits coupled effect of dilution, tortuosity and interfacial interactions. The concrete permeability coefficient can be accurately predicted through a quadratic polynomial fit, with errors within 5%. Optimizing the mix proportion of concrete requires simultaneously reducing the water-to-cement ratio and increasing the aggregate volume fraction. This study provides a theoretical and data-driven support for the design of underground hydrogen storage facilities.

混凝土是地下储氢设施的关键材料，其渗透性直接影响储氢设施的安全性。现有的研究主要集中在外加剂的渗透率和宏观渗透率上，未能反映复杂的多相渗透率特征。在本研究中，考虑水灰比和骨料体积的影响，在混凝土试件中进行了氢渗透试验。使用“COMSOL with MATLAB”方法构建了三维细观有限元模型，通过该模型进行了参数分析。通过SEM和CT试验研究试件的微观结构，为建立细观模型提供依据。建立了混凝土渗透系数预测模型，提出了低渗透混凝土的优化配合比设计。试验结果表明，水灰比和骨料体积分数对渗透率均有显著影响。该比例每增加0.1倍，砂浆渗透系数会增加2-3倍 ，而骨料体积分数每增加10%，混凝土渗透系数会降低约10%。模拟结果表明，混凝土渗流场具有非均匀性，并表现出稀释、扭曲和界面相互作用的耦合效应。通过二次多项式拟合可以准确预测混凝土渗透系数，误差在5%以内。优化混凝土配合比需要同时降低水灰比和提高骨料体积分数。该研究为地下储氢设施的设计提供了理论和数据支持。

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引用次数: 0

Synergistic mechanism of Fly Ash and LDH on the performance of second-recycled concrete aggregate exposed to sulfate attack 粉煤灰与LDH对硫酸盐侵蚀下二次再生混凝土集料性能的协同作用机理

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145258

Xiancui Yan , Zimo He , Shengbang Xu , Pinghua Zhu , Wei Yang , Chunhong Chen

Sulfate attack leads to severe deterioration in both recycled concrete and the resulting second-recycled concrete aggregate (SCA), limiting its sustainable application. Optimizing the mix design of recycled concrete to enhance SCA quality under such aggressive conditions is essential for advancing sustainable construction. This study investigated the synergistic effects and mechanism of Class C or Class F fly ash (CFA or FFA) and Layered Double Hydroxides (LDH) on the performance of recycled concrete and the SCA after 150 sulfate wet-dry cycles. Results demonstrated that 30 % CFA or 20 % FFA effectively mitigated the sulfate-attacked damage to the recycled concrete, while the specimens with 10 %-20 % CFA or 30 % FFA exhibited significantly more pronounced degradation under sulfate attack. Furthermore, LDH enhanced the sulfate resistance of both CFA and FFA modified recycled concrete. In terms of the performance of SCA, it was found that SCA with 10 %-20 % CFA or 30 % FFA was off-grade, whereas 20 % FFA + 2 % LDH yielded medium-grade SCA. With 20 % FFA or 30 % CFA, a sufficient amount of active silica was introduced for secondary pozzolanic reactions, forming additional C-S-H gel. At lower CFA levels (10 % - 20 %) or higher FFA levels (30 %), an inadequate quantity of available reactive silica or cement leaded to increased porosity within the cement matrix. The synergistic action of fly ash and LDH enhanced the SCA exposed to sulfate attack through two primary mechanisms: pozzolanic reactions and particle filling of fly ash improved the interface, whereas LDH adsorbed diffused sulfate ions. A novel contribution of this study is to provide a mix design strategy for the recycled concrete with CFA/FFA and LDH that ensures its multi-recycling under sulfate attack.

硫酸盐侵蚀导致再生混凝土和二次再生混凝土骨料（SCA）的严重劣化，限制了其可持续应用。在这种恶劣的条件下，优化再生混凝土的配合比设计以提高SCA质量对于推进可持续建筑至关重要。研究了C类和F类粉煤灰（CFA或FFA）与层状双氢氧化物（LDH）在硫酸盐干湿循环150次后对再生混凝土性能和SCA性能的协同作用及其机理。结果表明，掺量为30 % CFA或20 % FFA的再生混凝土可有效减轻硫酸盐侵蚀损伤，而掺量为10 %-20 % CFA或30 % FFA的再生混凝土在硫酸盐侵蚀下的降解更为明显。LDH还增强了CFA和FFA改性再生混凝土的抗硫酸盐性能。在SCA性能方面，发现含有10 %-20 % CFA或30 % FFA的SCA为下等级，而含有20 % FFA + 2 % LDH的SCA为中等级。用20 % FFA或30 % CFA，引入足够量的活性二氧化硅进行二次火山灰反应，形成额外的C-S-H凝胶。在较低的CFA水平（10 % - 20 %）或较高的FFA水平（30 %）时，可用活性二氧化硅或水泥的数量不足导致水泥基质孔隙度增加。粉煤灰与LDH的协同作用增强了SCA受硫酸盐侵蚀的主要机理：火山灰反应和粉煤灰的颗粒填充改善了界面，而LDH则吸附了扩散的硫酸盐离子。本研究的一个新贡献是提供了一种具有CFA/FFA和LDH的再生混凝土的配合比设计策略，以确保其在硫酸盐侵蚀下的多次回收。

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引用次数: 0

Long-term degradation of concrete fracture toughness under exposure to aggressive chloride environments 暴露于腐蚀性氯化物环境下混凝土断裂韧性的长期退化

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145255

Petr Miarka , Dominik Lisztwan , Dalibor Kocáb , Patrik Bayer , Petr Konečný

This paper presents the outcome of a long-term experimental study aimed at the effect of chloride attack on the concrete body, and its influence on the fracture performance. Fracture tests involved Brazilian discs with central notch (BDCN) made from concrete with blended cement as a binder. The BDCN samples were placed into a 50 % saturated sodium chloride solution (NaCl). Two initial conditions of porous space were considered, i.e., empty (air filled), and water-saturated. SEM observations are presented to discuss the hydration products as well as to study the damage to the microstructure. Additionally, the EDS analysis was employed to understand the origin of both hydration and corrosion products. The exposure to chlorides significantly, up to 26 %, reduces the fracture toughness K_IC depending on the exposure time and initial conditions of pore space. The concept of effective thickness B_eff that links microstructural degradation with macroscopic fracture behaviour was introduced.

本文介绍了一项针对氯离子侵蚀对混凝土体的影响及其对断裂性能影响的长期试验研究的结果。断裂试验采用混凝土和混合水泥作为粘合剂制成具有中心缺口的巴西圆盘（BDCN）。将BDCN样品置于50% %饱和氯化钠溶液（NaCl）中。考虑了多孔空间的两种初始条件，即空（充满空气）和水饱和。通过扫描电镜观察，讨论了水化产物，并研究了水化产物对微观结构的破坏。此外，EDS分析被用来了解水化和腐蚀产物的来源。氯化物的暴露显著降低了断裂韧性KIC，最大可达26% %，这取决于暴露时间和孔隙空间的初始条件。引入了将微观结构退化与宏观断裂行为联系起来的有效厚度Beff概念。

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引用次数: 0

Multiscale assessment of UHPC-UHPC wet joint interfaces via 3D laser scanning and mechanical testing 基于三维激光扫描和力学测试的UHPC-UHPC湿接合界面多尺度评价

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145235

Gan Wu , Kaiwei Lu , Jianan Qi , Hongyu Zhou , Jingquan Wang , Yiming Yao

This study systematically investigated the interfacial performance of ultra-high performance concrete (UHPC) wet joints through 3D laser scanning characterization and mechanical testing. Four surface treatment methods—manual chiseling (MC), high-pressure water jetting (WJ), steel wire mesh (SWM), and their combination (WJ+SWM)—were evaluated to establish quantitative relationships between roughness parameters obtained from 3D laser scanning parameters and mechanical properties. Results showed that treatment effectiveness ranked SWM > WJ > MC, enhancing flexural strength by 117.5 %, 100.5 %, and 43.4 %, and energy absorption by 216.3 %, 115.3 %, and 15.6 %, respectively, compared to control specimens without treatment. WJ and SWM significantly improved roughness parameters, increasing maximum depth, roughness ratio, and exposed fibers by up to 305 % compared to MC. Strong correlations existed between roughness parameters and mechanical performance, with exposed fiber count being the strongest predictor. Counterintuitively, the combined WJ+SWM treatment reduced strength by 25.6 % compared to SWM treatment due to fiber reorientation effects. Microstructural analysis revealed inherent weaknesses at the interface, with a higher degree of hydration observed in pre-cast UHPC compared to post-cast UHPC.

通过三维激光扫描表征和力学测试，系统研究了超高性能混凝土（UHPC）湿缝界面性能。对手工凿凿（MC）、高压水射流（WJ）、钢丝网（SWM）及其组合（WJ+SWM）四种表面处理方法进行了评估，以建立三维激光扫描参数获得的粗糙度参数与力学性能之间的定量关系。结果表明，处理效果为SWM >； WJ >； MC，与未处理的对照相比，抗弯强度分别提高了117.5 %、100.5 %和43.4 %，能量吸收分别提高了216.3 %、115.3 %和15.6 %。与MC相比，WJ和SWM显著改善了粗糙度参数，最大深度、粗糙度比和暴露纤维增加了305 %。粗糙度参数与机械性能之间存在很强的相关性，暴露纤维数是最强的预测因子。与直觉相反，由于纤维重定向效应，WJ+SWM复合处理的强度比SWM处理降低了25.6% %。微观结构分析揭示了界面上固有的弱点，与浇筑后的UHPC相比，预制UHPC的水化程度更高。

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引用次数: 0

Shrinkage and creep behavior of LWAC with fly ash cenospheres and desert sand 粉煤灰微球和沙漠砂对轻质混凝土收缩蠕变特性的影响

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145256

Junlin Guo , Dan Gan

This study experimentally investigated the shrinkage and creep behavior of lightweight aggregate concrete (LWAC) with fly ash cenospheres (FAC) and desert sand (DS) during 120 days. The test variables include the DS replacement ratio (0 %, 20 %, 30 %, 40 %), the FAC replacement ratio (0 %, 10 %, 20 %, 30 %), and the curing age (7d, 14d, 28d). The test results show that the shrinkage decreases and the creep strain increases as the FAC replacement ratio increases, respectively. The highest shrinkage strain and creep rate were observed in specimens containing 40 % DS, with shrinkage strain and creep rate values of 632.50 με and 64.79 MPa⁻¹ at 120 days, respectively. These values increased by 33.56 % and 40.90 % respectively, when compared to specimens without FAC and DS. The inclusion of DS and FAC significantly influences the shrinkage and creep behavior of LWAC, primarily by altering the water and stress distribution within the matrix. This study proposes modified predictive models for shrinkage and creep of LWAC with FAC and DS, showing better accuracy than ACI 209 and MC90.

试验研究了掺有粉煤灰微球（FAC）和沙漠砂（DS）的轻骨料混凝土（LWAC）在120天内的收缩和徐变特性。试验变量包括DS替代率（0 %、20 %、30 %、40 %）、FAC替代率（0 %、10 %、20 %、30 %）和养护龄期（7d、14d、28d）。试验结果表明，随着FAC替代率的增大，收缩率减小，蠕变应变增大；当DS含量为40 %时，120 d的收缩应变和蠕变速率最高，分别为632.50 με和64.79 MPa−1。与没有FAC和DS的标本相比，这些值分别增加了33.56 %和40.90 %。DS和FAC的加入显著影响了LWAC的收缩和蠕变行为，这主要是通过改变基体内部的水和应力分布来实现的。本研究提出了基于FAC和DS的改进的LWAC收缩和蠕变预测模型，其准确性优于ACI 209和MC90。

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引用次数: 0

Temperature evolution in hot recycled asphalt mixtures incorporating flat- and elongated-shaped aggregates of different sizes during mixing 含不同尺寸的扁平和细长形集料的热再生沥青混合料在混合过程中的温度演变

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145212

Jiangyu Liu , Jiwei Cao , Zhongshi Pei , Wei Hu , Junyan Yi

In the production of hot recycled asphalt mixture, the mixing method and material characteristic are the decisive factors determining the quality and cost of the products. This study investigated the influence of flat- and elongated-shaped aggregate of different sizes on the temperature evolution and thermal equilibrium process of hot recycled asphalt mixture containing 30 % recycled asphalt pavement (RAP) under various mixing conditions. Digital models of real shaped aggregates were utilized to represent the new and RAP particles, and a horizontal mixing apparatus was designed to replicate the actual mixing environment in DEM. Meanwhile, conventional mixture samples were fabricated and digital image processing technology was employed to visualize the temperature evolution of recycled asphalt, thereby validating the simulation results. The simulation results have revealed that the temperature evolution of recycled asphalt mixture was divided into three distinct stages. The inclusion of flat- and elongated-shaped fine aggregates smaller than 4.75 mm was found to accelerate thermal transition within the mixtures. Moreover, the preheating temperature of RAP played a crucial role in governing the rate of thermal transfer between new and RAP particles. Experimental observations demonstrated a consistent trend with the simulation outcomes, confirming the validity and reliability of the numerical model. The findings of this research provide valuable insights into enhancing the effective utilization of RAP and reducing production costs in hot recycled asphalt mixture manufacturing.

在热再生沥青混合料的生产中，混合方法和材料特性是决定产品质量和成本的决定性因素。研究了不同配比条件下，不同粒径的扁平骨料和细长骨料对含30% %再生沥青路面（RAP）的热再生沥青混合料的温度演化和热平衡过程的影响。利用真实形状集料的数字模型来代表新颗粒和RAP颗粒，并设计了一个水平混合装置来模拟DEM中的实际混合环境。同时，制作常规混合料样品，采用数字图像处理技术对再生沥青的温度演变进行可视化处理，验证模拟结果。模拟结果表明，再生沥青混合料的温度演变分为三个不同的阶段。发现小于4.75 mm的扁平和细长形细集料的加入加速了混合物内的热转变。此外，RAP的预热温度对新颗粒与RAP颗粒之间的传热速率起着至关重要的控制作用。实验观测结果与模拟结果基本一致，证实了数值模型的有效性和可靠性。本研究结果为提高RAP的有效利用和降低热再生沥青混合料的生产成本提供了有价值的见解。

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引用次数: 0

Evaluation of printing performance of cementitious pastes with alternative powders 替代粉末胶凝体的印刷性能评价

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145274

João Teixeira , Manuel Jesus , Bárbara Rangel , Jorge Lino Alves , Lino Maia

The adoption of 3D concrete printing presents a promising pathway toward automation and sustainability in the construction industry. However, the high dependence on Portland cement in 3D printable materials raises environmental concerns. This study investigates the fresh-state behaviour, specifically extrudability and buildability, of cementitious pastes for 3D printable compositions, where Portland cement was replaced by alternative powders, including supplementary cementitious materials and powders derived from industrial and construction waste. Through flow table and 3D printing tests, this research evaluates pastes made with different Portland cements and powders. Each paste was tested in a range of water-to-powder ratios, from the minimum required for extrusion through the nozzle to the point where the excessive water causes the printed layers to collapse. Materials tested include limestone filler, quartz powder, metakaolin, silica fume, fly ash, waste marble, granite and slate powder, clay brick powder, bottom ashes from municipal incineration and sugarcane bagasse ashes. The results reveal that metakaolin provided the best balance between extrudability and buildability, while some waste-derived powders, such as marble powder, showed poor performance, highlighting the good performance of slate powder. The findings underscore the need for tailored mix design strategies and particle refinement to optimise 3D concrete printing mixtures for sustainability and performance. The study demonstrated that flow table tests alone are insufficient to determine a material's suitability for 3D concrete printing, they must be complemented by extrusion tests to fully assess its 3D printing performance.

采用3D混凝土打印为建筑行业的自动化和可持续性提供了一条有希望的途径。然而，3D打印材料对硅酸盐水泥的高度依赖引发了环境问题。本研究调查了用于3D打印组合物的胶凝体的新鲜状态行为，特别是可挤压性和可建造性，其中波特兰水泥被替代粉末取代，包括补充胶凝材料和来自工业和建筑废物的粉末。通过流动表和3D打印测试，本研究对不同硅酸盐水泥和粉末制成的膏体进行了评价。每种糊状物都在一系列水粉比下进行测试，从通过喷嘴挤出所需的最小值到过量水导致打印层坍塌的点。测试的材料包括石灰石填料、石英粉、偏高岭土、硅灰、粉煤灰、废大理石、花岗岩和板岩粉、粘土砖粉、城市焚烧的底灰和甘蔗甘蔗渣灰。结果表明，偏高岭土在可挤压性和可建造性之间取得了最佳的平衡，而一些垃圾衍生粉末（如大理石粉）的性能较差，突出了板岩粉的良好性能。研究结果强调了定制混合设计策略和颗粒细化的必要性，以优化3D混凝土打印混合物的可持续性和性能。研究表明，单靠流动表测试不足以确定材料是否适合3D混凝土打印，必须辅以挤压测试，以全面评估其3D打印性能。

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引用次数: 0

Stabilization mechanism of ettringite induced by ferric nitrate nonahydrate in BYF–OPC–Ternesite cement: Insights from DFT and experimental analysis 非水合硝酸铁诱导钙矾石在BYF-OPC-Ternesite水泥中的稳定机制：来自DFT和实验分析的见解

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145209

Hao Qian , Weihe Ye , Qingjun Ding , Gaozhan Zhang , Songtao Hu , Yun Huang , Hongbo He

The stability of ettringite plays a critical role in ensuring long-term performance development in high-alumina cement systems. In this study, ferric nitrate nonahydrate (FNH) was introduced as both an iron and nitrate source to systematically investigate the effects of Fe³ ⁺ incorporation on macroscopic performance, pore structure development, and crystallization evolution of Belite–ye’elimite–ferrite (BYF)–Portland cement (OPC)–ternesite composite system. Compressive strength tests combined with one-way ANOVA demonstrated that FNH incorporation significantly enhanced compressive strength at all curing ages (p < 0.05), with the optimized mixture exhibiting a 22.6 % increase in 1 d compressive strength and superior compressive strength retention at 28 d. Autogenous shrinkage measurements revealed that FNH markedly reduced overall shrinkage and induced slight long-term swelling. Mercury intrusion porosimetry showed pronounced pore refinement in FNH-modified systems, with pores smaller than 20 nm accounting for over 60 % of the total porosity. Despite the theoretically increased capillary stress associated with pore refinement, overall shrinkage was mitigated due to enhanced crystallization-induced expansion. XRD, XPS and SEM-EDS analyses consistently confirmed the formation of Fe-substituted ettringite (Fe-AFt). Complementary DFT calculations further indicate that Fe³ ⁺ incorporation strengthened the covalent character of Fe–O bonds and enhanced S–O bond polarity. These effects led to a pressure-tolerant framework with improved morphological stability and higher bulk modulus, thereby contributing to superior long-term strength retention and dimensional stability of BYF–OPC–ternesite composite cementitious systems.

钙矾石的稳定性对确保高铝水泥体系的长期性能发展起着至关重要的作用。本研究引入非水合硝酸铁（FNH）作为铁源和硝酸盐源，系统研究了Fe³ +掺入对Belite-ye 'elimite-ferrite (BYF) -Portland cement (OPC) -ternesite复合体系宏观性能、孔隙结构发育和结晶演化的影响。抗压强度测试结合单因素方差分析表明，FNH掺入显著提高了所有龄期的抗压强度（p <； 0.05），优化后的混合物在第1天抗压强度增加22.6% %，在第28天抗压强度保持良好。自收缩测量显示，FNH显著降低了整体收缩，并引起轻微的长期膨胀。压汞孔隙测量结果表明，fnh改性体系孔隙细化明显，小于20 nm的孔隙占总孔隙度的60% 以上。尽管理论上毛细血管应力增加与孔隙细化有关，但由于结晶引起的膨胀增强，总体收缩得到了缓解。XRD、XPS和SEM-EDS分析一致证实了铁取代钙矾石（Fe-AFt）的形成。互补DFT计算进一步表明，Fe³ +增强了Fe - o键的共价特性，增强了S-O键的极性。这些作用形成了耐压框架，具有更好的形态稳定性和更高的体积模量，从而有助于BYF-OPC-ternesite复合胶凝体系的长期强度保持和尺寸稳定性。

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引用次数: 0

Mechanical properties and abrasion resistance of CNTs cement mortars: Hydration behavior and microscopic mechanisms 碳纳米管水泥砂浆的力学性能和耐磨性：水化行为和微观机制

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145263

Jicheng Xie , Bin Liu , Xiaowen Wang , Yasen Tang , Jingli Wei , Jingjing Luo , Zheng Chen

This study examines the effects of four different types of carbon nanotubes (CNTs) on the mechanical properties and abrasion resistance of cement mortar, with a focus on comparing the differences in physical and chemical properties. The underlying mechanisms were elucidated through a series of microstructural characterization techniques, including QXRD, MIP, and SEM. The results indicate that all CNTs improve performance, with surface chemical properties exerting a greater influence than physical properties. The performance improvement effects rank as follows: CH > CC > CO > CS. Hydroxyl-functionalized CNTs (CH) exhibit optimal performance at a 0.15 % dosage, with compressive and flexural strengths increased by 46.5 % and 63.9 %, respectively, and abrasion resistance reduced by 58.3 %. A strong quadratic correlation was established between mechanical strength and abrasion loss. The superior performance of CH is attributed to its excellent dispersion enabled by hydrophilic -OH groups, which facilitates effective filling, nucleation, and bridging effects, promotes cement hydration and refines pore structure, resulting in a 26.1 % reduction in porosity. CS with smaller diameter and higher specific surface area are more prone to severe aggregation due to van der Waals forces, impairing its functional roles and introducing defect points, leading to inferior hydration and pore structure. The finding of this study hold significant implications for promoting the effective application of CNTs in practical engineering construction.

本研究考察了四种不同类型的碳纳米管（CNTs）对水泥砂浆力学性能和耐磨性的影响，重点比较了其物理和化学性能的差异。通过QXRD、MIP和SEM等一系列微观结构表征技术对其机理进行了分析。结果表明，所有碳纳米管都能提高材料的性能，其中表面化学性质的影响大于物理性质。性能提升效果排序如下：CH >； CC >； CO >； CS。羟基功能化碳纳米管（CH）在0.15 %的用量下表现出最佳性能，抗压强度和抗弯强度分别提高了46.5% %和63.9 %，耐磨性降低了58.3% %。机械强度与磨损损失之间存在较强的二次相关关系。CH的优异性能归功于其亲水性-OH基团的优异分散性，有利于有效的填充、成核和桥接作用，促进水泥水化，细化孔隙结构，孔隙率降低26.1% %。直径越小、比表面积越高的CS，由于范德华力的作用，更容易发生严重的聚集，削弱其功能作用，引入缺陷点，导致水化和孔隙结构较差。本研究的发现对于促进CNTs在实际工程建设中的有效应用具有重要意义。

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