Cement & concrete composites最新文献_第7页

Characterizing and modelling the bond-slip behaviour of steel bars in 3D printed engineered cementitious composites 3D打印工程胶凝复合材料中钢筋粘结滑移行为的表征和建模

IF 10.8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-01-22 DOI: 10.1016/j.cemconcomp.2025.105936

Meng Chen , Kanghao Yu , Tong Zhang , Yuting Wang

Embedding rebars in 3D printed engineered cementitious composites (3DP-ECC) promises to improve the structural toughness and loading capacity, while a robust bond between them is critical for digital construction with reinforcements. This paper presents a series of pull-out tests on the bond behaviour between rebars and 3DP-ECC to investigate the effects of variable rebar arrangement direction, diameter and anchorage length. Results indicate that the failure patterns mainly showed pull-out failure due to the lower probability of interlayer splitting failure caused by the improved interlayer fracture resistance capacity in 3DP-ECC compared to ordinary 3D printed concrete. The rebar direction most significantly affected the slip stage in the bond stress-slip curve, whereas the rebar diameter and anchorage length had almost no effect on the curves. The bond strength of the printed specimens in the parallel direction enhanced by 2.9%–10.5 % than that in the vertical direction, while it declined by 27.4%–27.6 % as the rebar diameter increased from 8 to 14 mm. Moreover, a bond-slip constitutive model for steel bar reinforced 3DP-ECC was established to predict the bond behaviour as a function of the rebar location and physical characteristics. The exploration of the bond behaviour and constitutive relationships of steel bar reinforced 3DP-ECC provides a basis for integrated performance evaluation in practical application.

在3D打印工程胶凝复合材料（3D - ecc）中嵌入钢筋有望提高结构韧性和承载能力，而它们之间的牢固粘合对于带有增强材料的数字建筑至关重要。本文对钢筋与3d - p - ecc之间的粘结性能进行了一系列拉拔试验，研究了不同钢筋布置方向、直径和锚固长度对钢筋粘结性能的影响。结果表明：与普通3D打印混凝土相比，3D打印混凝土的层间抗断裂能力提高，导致层间分裂破坏的概率降低，破坏模式以拉出破坏为主；在粘结-滑移曲线中，钢筋方向对滑移阶段的影响最为显著，而钢筋直径和锚固长度对滑移阶段的影响几乎为零。当钢筋直径从8 mm增加到14 mm时，平行方向的粘结强度比垂直方向的粘结强度提高2.9% ~ 10.5%，降低27.4% ~ 27.6%。此外，建立了钢筋3d - ecc的粘结-滑移本构模型，预测了钢筋位置和物理特性对粘结行为的影响。探索钢筋3d - p - ecc的粘结行为和本构关系，为实际应用中的综合性能评价提供依据。

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引用次数: 0

Bottom-up innovation for sustainable leakproof Engineered Cementitious Composites (ECC) pipe: Design method, ECC material, and pipe structure 可持续防漏工程水泥复合材料（ECC）管道的自下而上创新：设计方法、ECC材料和管道结构

IF 10.8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-01-22 DOI: 10.1016/j.cemconcomp.2025.105947

He Zhu , Jinping Ou , Dongsheng Li , Aamer Bhutta , Georgios Zapsas , Waleed Nasser , Mohammed Mehthel , Oscar Salazar , Victor C. Li

Low-carbon, low-cost, and durable water pipelines are urgently needed for sustainable cities. In this study, low carbon, cost-effective, leakproof Engineered Cementitious Composites (ECC) pipes were developed benefiting from the proposed ECC pipe design model and material innovation. The proposed model has been experimentally validated on ECC beam and ECC pipe. The developed desert sand Engineered Cementitious Composites attained the highest tensile strength (12.6 MPa) and ductility (12.1 %) among the published desert sand ECCs, enabling a sustainable ECC pipe with thinner wall thickness while attaining higher performance. Under the three-edge loading test, the deformation capacity of ECC pipe was 4–6 times that of steel reinforced concrete (RC) pipes. Even with two-thirds the wall thickness of an RC pipe, ECC pipes reached 2.6 times in load capacity of the highest Class V pipes (ASTM C76). The developed ECC pipes hold promise for the next generation of sustainable pipelines.

低碳、低成本、耐用的输水管道是城市可持续发展的迫切需要。在本研究中，低碳、低成本、防泄漏的工程水泥复合材料（ECC）管道的开发得益于所提出的ECC管道设计模型和材料创新。该模型已在ECC梁和ECC管上进行了实验验证。开发的沙漠砂工程胶凝复合材料在已发表的沙漠砂ECC中具有最高的抗拉强度（12.6 MPa）和延展性（12.1%），使ECC管道具有更薄的壁厚，同时具有更高的性能。在三边加载试验下，ECC管的变形能力是钢筋混凝土（RC）管的4-6倍。即使壁厚只有RC管的三分之二，ECC管的承载能力也达到了最高V类管（ASTM C76）的2.6倍。开发的ECC管道有望成为下一代可持续管道。

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引用次数: 0

Enhancing photocatalytic efficiency and interfacial bonding on cement-based surfaces by constructing CaO-TiO2 hybrid catalysts 通过构建 CaO-TiO2 混合催化剂提高水泥基表面的光催化效率和界面结合力

IF 10.8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-01-21 DOI: 10.1016/j.cemconcomp.2025.105944

Xunli Jiang , Jian-Xin Lu , Yuqing Zhang , Chi Sun Poon

The application of titanium dioxide (TiO₂) coating in cement-based materials faces challenges regarding its durability. This study presented the concept of ‘induced bonding’ for enhancing coating adhesion. By modifying TiO₂ with CaO, nucleation sites were constructed on its surface, inducing the growth of hydration products and connecting the catalytic materials to the substrate. As a result, a novel dual-effect CaO-TiO₂ hybrid catalytic material with enhanced photocatalytic efficiency and interfacial bonding was successfully developed using a mechanochemical-thermochemical method. The CaO-TiO₂ catalyst was coated onto cement surfaces, and the mechanisms of interface enhancement were revealed by micro-scratch and microstructural tests. The results indicated that the synthetic catalytic materials exhibited excellent NO photocatalytic degradation performance, particularly at an activation temperature of 300 °C; the optimized NO degradation efficiency hit around 40 % with a NO_x comprehensive removal amount approximately twice that of conventional TiO₂. Moreover, the minimal generation of NO₂ demonstrated a strong photocatalytic selectivity. This exceptional photocatalytic performance can be attributed to the interaction between TiO₂ and CaO, along with its derivatives such as CaTiO₃ and CaCO₃, which promoted the formation of active species (•OH, •O²⁻, h⁺), and increased the absorption efficiency in the visible light region. Furthermore, the wear resistance and interface critical load of CaO-TiO₂ coatings were more robust than reference coatings. The CaO-TiO₂ catalyst promoted hydration to form widely distributed and interlocked fibrous C-S-H gel, bridging the catalyst particles and enhancing the adhesion of the coating with the cement substrate, thereby improving its interfacial bonding performance.

二氧化钛涂层在水泥基材料中的应用面临着耐久性方面的挑战。本研究提出了“诱导键合”的概念，以提高涂层的附着力。通过CaO修饰TiO2，在其表面构建成核位点，诱导水化产物生长，将催化材料与底物连接。结果表明，采用机械化学-热化学的方法，成功地开发了一种具有增强光催化效率和界面键合的新型双效应CaO-TiO2杂化催化材料。将CaO-TiO2催化剂涂覆在水泥表面，并通过显微划痕和显微结构测试揭示了界面增强机理。结果表明，合成的催化材料具有优异的NO光催化降解性能，特别是在活化温度为300℃时；优化后的NO降解效率达到40%左右，NOx综合去除率约为传统TiO2的2倍。此外，少量生成NO2表现出较强的光催化选择性。这种优异的光催化性能可归因于TiO2与CaO及其衍生物CaTiO3和CaCO3之间的相互作用，促进了活性物质（•OH，•O2−,h+）的形成，并提高了可见光区的吸收效率。此外，CaO-TiO2涂层的耐磨性和界面临界载荷比参比涂层更强。CaO-TiO2催化剂促进水合作用形成分布广泛且互锁的纤维状C-S-H凝胶，桥接催化剂颗粒，增强涂层与水泥基材的附着力，从而提高其界面粘合性能。

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引用次数: 0

Unbiased rheological properties determined by adversarial training with Bingham equation 利用宾汉方程的对抗训练确定无偏流变特性

IF 10.8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-01-21 DOI: 10.1016/j.cemconcomp.2025.105943

In Kuk Kang , Tae Yong Shin , Jae Hong Kim

The Bingham model is generally used to describe the flow of cement-based materials, and its parameters, such as yield stress and plastic viscosity, are measured using a rheometer. However, the rheological measurement does not provide the unique Bingham parameters for a single material when rheometers take different rheological geometries or measuring protocols. This study constructs a model that can yield the ideal Bingham parameters with the rheological measurement. We first introduce the generation of an ideal domain strictly following the Bingham equation, and then an unsupervised domain adaptation by adversarial training makes it possible to match the rheological measurement with the ideal Bingham parameters. The proposed model is applied to the experimental data measured with mortar samples, where the measurements for a single sample are conducted by three different measuring protocols. The resultant (ideal) Bingham parameters are identical regardless of the protocols used.

通常采用Bingham模型来描述水泥基材料的流动，其屈服应力和塑性粘度等参数是用流变仪来测量的。然而，当流变仪采用不同的流变几何形状或测量方案时，流变测量不能为单一材料提供独特的宾厄姆参数。本研究构建了一个可以通过流变测量得到理想Bingham参数的模型。我们首先引入严格遵循Bingham方程的理想域的生成，然后通过对抗训练的无监督域自适应使得流变测量与理想Bingham参数匹配成为可能。该模型适用于砂浆样品测量的实验数据，其中单个样品的测量采用三种不同的测量方案进行。所得的（理想的）宾厄姆参数是相同的，无论使用的协议。

引用次数: 0

Multi-scale analysis of degradation mechanisms in magnesium phosphate cement paste under wet-dry cycling 干湿循环条件下磷酸镁水泥浆体降解机理的多尺度分析

IF 10.8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-01-17 DOI: 10.1016/j.cemconcomp.2025.105939

Zihan Zhou , Haisen Jin , Qinyuan Liang , Qiang Wang , Jianshuai Hao , Shiyu Zhuang

Magnesium phosphate cement paste (MPC) is a promising rapid-repair material for pavements but is prone to degradation under wet-dry (W-D) cycling, which limits its durability. Current research lacks a detailed understanding of the damage and degradation mechanisms of MPC under these conditions. This study investigates the macroscopic mechanical behavior and mesoscopic damage progression of MPC during W-D cycling. Results reveal that initial W-D cycles enhance the strength and modulus of MPC due to secondary hydration, followed by a decline and a shift in failure mode from brittle to ductile. Damage advances from the exterior inward, with increased pore connectivity and changes in fracture modes, from tensile splitting to tensile-shear failure driven by W-D-induced macrocracks. Key degradation mechanisms include K-struvite dissolution, uneven thermal swelling, and fatigue from cyclic moisture. This work provides insights for enhancing the mechanical performances of MPC in moisture-variable environments.

磷酸镁水泥浆（MPC）是一种很有前途的路面快速修复材料，但在干湿循环（W-D）下容易降解，这限制了其耐久性。目前的研究缺乏对这些条件下MPC损伤和降解机制的详细了解。研究了复合材料在W-D循环过程中的宏观力学行为和细观损伤进展。结果表明，由于二次水化作用，初始W-D循环提高了MPC的强度和模量，随后强度和模量下降，破坏模式从脆性向延性转变。随着孔隙连通性的增加和破裂模式的变化，破坏从外部向内推进，从拉伸分裂到由w - d诱导的宏观裂纹驱动的拉伸-剪切破坏。关键的降解机制包括k -鸟粪石溶解、不均匀热膨胀和循环水分疲劳。这项工作为提高MPC在变湿环境中的力学性能提供了见解。

引用次数: 0

Nano-mechanism of graphene oxide reinforced fly ash-slag based geopolymer materials to form high polymerization degree C-(A)-S-H: A new view of physical-chemical synergistic effect 氧化石墨烯增强粉煤灰-矿渣基地聚合物材料形成高聚合度C-(A)- s - h的纳米机理：物理化学协同效应的新视角

IF 10.8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-01-17 DOI: 10.1016/j.cemconcomp.2025.105937

Ben Li , Kai-Hang Li , Ying-Wu Zhou , Hu Xu , Can-Hao Zhao , Ying Yu , Zhuo-Cheng Li

This study mainly investigated the effect and mechanism of graphene oxide (GO) on the nucleation of C-(A)-S-H in fly ash-slag based geopolymer. A variety of material characterization methods and electronic structure analysis methods were combined to analyze the nanostructure changes and electronic transitions generated during the reduction of GO in an alkaline environment. Based on this change, the effect of GO/RCO on the binding and mode of calcium ions was explored, which provided a basis for revealing the nucleation and development of C-(A)-S-H. The results show that, GO is reduced in an alkali-excited environment, resulting in nanostructure changes and the formation of a strong electron cloud/field at its edge, thereby changing its binding mode to calcium ions (from chemical binding to physical electrostatic adsorption). This physical-chemical change makes the edge of GO form a calcium ion enrichment environment, which provides sites and prerequisites for inducing and driving the nucleation and growth of C-(A)-S-H. However, excessive GO will lead to the metastable state and multi-aluminum phase structure of C-(A)-S-H, which is not conducive to the development of comprehensive properties such as mechanics of geopolymers.

本文研究了氧化石墨烯（GO）在碱激发环境下的还原过程及其化学组成、纳米结构和电子能级演变。在此基础上，探讨了还原氧化石墨烯对钙离子的影响，以及在粉煤灰-矿渣基地聚合物材料中诱导和促进C-(A)- s - h水化产物成核发育的机理。实验结果表明，当氧化石墨烯分散在碱性活化剂中时，其纳米片边缘恢复了石墨晶格的部分共轭结构，并且原本以折叠形式存在的纳米形态趋于平坦。同时，氧化石墨烯的含氧官能团被削弱，但层间的范德华力增加，电子云和电子能级之间发生能量跃迁。碱活化的还原氧化石墨烯改变了其与钙离子的结合方式和结合能力，为C-(A)- s - h的成核提供了纳米位点。氧化石墨烯的还原反应使地聚合物材料来自富钙环境，驱动高钙含量、高聚合度的C-(a)- s - h的生成，诱导Al-O四面体取代Si-O四面体的程度。以上研究结果为氧化石墨烯材料改善地聚合物材料或水泥基材料的机理研究或纳米尺度模拟提供了新的思路。

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引用次数: 0

Improved corrosion resistance of 316 stainless steel in calcium sulfoaluminate cement incorporated with red mud and citrate 红泥和柠檬酸盐掺入硫铝酸钙水泥中提高316不锈钢的耐腐蚀性

IF 10.8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-01-16 DOI: 10.1016/j.cemconcomp.2025.105940

Xiaocheng Zhou , Jinjie Shi

The incorporation of red mud (RM) in calcium sulfoaluminate (CSA) cement offers a cost-effective and environmentally friendly solution for rehabilitation engineering, resulting in reduced carbon emissions. However, it may further reduce the setting time of CSA cement, thus causing inconvenience during construction. Moreover, the corrosion resistance of steel in CSA cement blended with RM is unclear. Therefore, in this study, CSA cement blended with RM and citrate has been specifically designed for rehabilitation engineering where citrate functions as both retarding admixture and corrosion inhibitor. Although RM negatively affects the passivity of 316 stainless steel (316ss), it enhances the pitting corrosion resistance of 316ss in CSA cement blended with RM. Furthermore, the formation of a citrate-related protective layer contributes to the improved passivation ability and pitting corrosion resistance of 316ss in CSA cement incorporated with RM and citrate.

将赤泥（RM）掺入硫铝酸钙（CSA）水泥中，为修复工程提供了一种既经济又环保的解决方案，从而减少了碳排放。但可能会进一步缩短CSA水泥的凝结时间，给施工带来不便。此外，钢在与RM混合的CSA水泥中的耐蚀性尚不清楚。因此，本研究专门为康复工程设计了RM与柠檬酸盐混合的CSA水泥，其中柠檬酸盐兼具缓凝外加剂和缓蚀剂的功能。RM虽然对316不锈钢（316ss）的钝化性能有负面影响，但在掺入RM的CSA水泥中，它提高了316ss的抗点蚀性能。此外，在掺入RM和柠檬酸盐的CSA水泥中，形成与柠檬酸盐相关的保护层有助于提高316ss的钝化能力和抗点蚀能力。

引用次数: 0

Evaluation of the induced mechanical deterioration of ASR-affected concrete under varied moisture and temperature conditions 不同湿度和温度条件下asr影响混凝土诱发力学劣化的评价

IF 10.8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-01-15 DOI: 10.1016/j.cemconcomp.2025.105942

O.D. Olajide , M.R. Nokken , L.F.M. Sanchez

Moisture and temperature are critical for developing alkali-silica reaction (ASR) in concrete. However, the influence of these exposure conditions on ASR-induced deterioration, specifically mechanical property losses, has not been well studied. To further our understanding, concrete cylinders made with Spratt reactive coarse aggregates and boosted in alkalis to 5.25 kg/m³

{N a}_{2} O_{e q}

were manufactured and stored at three different temperatures (i.e., 21 °C, 38 °C, and 60 °C) under numerous relative humidities (i.e., 100 %, 90 %, 82 %, 75 %, and 62 %). The reduction in mechanical properties was assessed using the stiffness damage test (SDT), direct shear and compressive strength tests. Overall, most results for mechanical properties showed a strong linear trend with expansion, with the exception of the modulus of elasticity and shear strength. In low moisture conditions that experienced both drying shrinkage and ASR, the expansion level associated with a given mechanical property loss differs from that in high moisture conditions due to early age cracks that developed in the cement paste. In most published research, expansion is the primary criteria used in assessing role of exposure conditions. However, it was found that expansion levels alone are not reliable indicators of induced deterioration due to the coupled mechanism. Furthermore, the impact of this phenomenon varies with the different mechanical properties assessed. Additionally, the moisture threshold required for the reaction was evaluated by considering the impact on mechanical properties.

湿度和温度对混凝土中碱硅反应（ASR）的产生至关重要。然而，这些暴露条件对 ASR 引起的劣化（特别是机械性能损失）的影响还没有得到很好的研究。为了进一步了解情况，我们制造了使用斯普拉特活性粗集料并在碱中添加至 5.25kg/m³ 的混凝土圆柱体，并将其存放在三种不同温度（即 21°C、38°C 和 60°C）和多种相对湿度（即 100%、90%、82%、75% 和 62%）条件下。通过刚度破坏试验（SDT）、直接剪切试验和抗压强度试验评估了机械性能的降低情况。总体而言，除弹性模量和剪切强度外，大多数机械性能结果都显示出强烈的线性膨胀趋势。在同时经历干燥收缩和 ASR 的低湿度条件下，由于水泥浆中出现的早期龄期裂缝，与特定机械性能损失相关的膨胀水平与高湿度条件下的膨胀水平不同。在大多数已发表的研究中，膨胀是评估暴露条件作用的主要标准。但研究发现，由于耦合机制的存在，仅凭膨胀水平并不能可靠地反映诱导劣化。此外，这种现象的影响因所评估的不同机械性能而异。此外，考虑到对机械性能的影响，还对反应所需的湿度阈值进行了评估。

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引用次数: 0

Mechanism analysis of microwave-carbonation solidification for carbide slag-based low-carbon materials 碳化物渣基低碳材料微波碳化凝固机理分析

IF 10.8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-01-15 DOI: 10.1016/j.cemconcomp.2025.105938

Run-Sheng Lin , Yongpang Liao , Chaoshu Fu , Ting-Hong Pan , Rongxin Guo , Xiao-Yong Wang

This study proposes an innovative strategy for compacting carbide slag-based low-carbon bricks (CS-LCB) through a combination of microwave and carbonation curing, aiming to improve the properties through microwave pretreatment combined with carbonation curing and to realize the preparation of low-carbon materials. The effects of microwave pretreatment on the main properties of CS-LCB-containing limestone and fly ash were systematically investigated. After carbonation curing, the pressed CS-LCB exhibited strong strength and effective CO₂ capture capacity. The nucleation effect of limestone helps accelerate the carbonation rate of CS-LCB. In contrast, the interaction between fly ash and carbide slag effectively improves the microstructure. Microwave pretreatment further accelerates the pozzolanic reaction and early carbonation rate of fly ash and carbide slag, improving the early strength of CS-LCB. Additionally, after 14 days of carbonation, CS-LCB retained more than 70.8 % of its initial strength below 500 °C but nearly completely lost its strength at 900 °C.

本研究提出了一种创新的微波与碳化固化相结合的电石渣基低碳砖（CS-LCB）压制策略，旨在通过微波预处理与碳化固化相结合的方法改善其性能，实现低碳材料的制备。系统研究了微波预处理对含 CS-LCB 石灰石和粉煤灰主要性能的影响。碳化固化后的压制 CS-LCB 具有较强的强度和有效的二氧化碳捕集能力。石灰石的成核效应有助于加快 CS-LCB 的碳化速度。相比之下，粉煤灰和碳化物渣之间的相互作用能有效改善微观结构。微波预处理进一步加快了粉煤灰和电石渣的胶凝反应和早期碳化速度，提高了 CS-LCB 的早期强度。此外，经过 14 天的碳化后，CS-LCB 在 500 °C 以下保持了 70.8% 以上的初始强度，但在 900 °C 时几乎完全丧失了强度。

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引用次数: 0

Unlocking the role of silica gel in enhancing mechanical properties and water resistance of magnesium oxysulfate cement 揭示了硅胶在提高硫酸镁水泥力学性能和耐水性中的作用

IF 10.8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-01-15 DOI: 10.1016/j.cemconcomp.2025.105941

Tingting Zhang , Qun Guo , Xiaoyang Chen , Chris Cheeseman , Hao Wang , Jun Chang

The continuous hydration of residual periclase to form brucite with expansive stress remains an issue for the utilization of hardened magnesium oxysulfate (MOS) cement in humid environments. This study explored converting residual periclase and brucite into magnesium silicate hydrate (M–S–H) gel to enhance the mechanical properties of MOS cement after water immersion. Changes to the hydration process, strength development, phase composition, microstructure, and pore structure of MOS cement with silica gel (SG) before and after immersion in water were investigated. Results show that M–S–H gel with encapsulation and cohesiveness formed at very early ages reduced the fluidity and initial setting time of MOS slurry and accelerated the hydration of periclase to form 3 Mg(OH)₂·MgSO₄·8H₂O, thereby shortening the final setting time. The addition of SG complicated the forming process of 5 Mg(OH)₂·MgSO₄·7H₂O (Phase 517), extending its formation period but increasing its content and crystallite size. Synergistic growth between layered M–S–H gel and Phase 517 whiskers optimized the pore structure and densified the matrix, enhancing the early and later mechanical strength of MOS cement by 40%–100 %. When MOS cement with SG was immersed in water, the conversions of residual periclase and brucite into M–S–H gel occurred. Under conditions where the formation rate of M–S–H gel exceeded that of brucite and the consumption of brucite surpassed its formation, SG allowed the mechanical strength and microstructure of MOS cement to develop further, despite MOS cement being immersed in water. However, this enhancement mechanism was effective only when SG dosage was in the range of 5–10 wt%.

在潮湿环境中使用硬化的草酸镁（MOS）水泥时，残留的珍珠岩在膨胀应力作用下持续水化形成青绿石仍是一个问题。本研究探讨了将残留的珍珠岩和青金石转化为水合硅酸镁（M-S-H）凝胶，以提高 MOS 水泥浸水后的机械性能。研究了含硅凝胶（SG）的 MOS 水泥在浸水前后的水化过程、强度发展、相组成、微观结构和孔隙结构的变化。结果表明，在很早的龄期就形成的具有包裹性和内聚性的 M-S-H 凝胶降低了 MOS 泥浆的流动性和初凝时间，并加速了珍珠质的水化形成 3Mg(OH)2-MgSO4-8H2O，从而缩短了终凝时间。添加 SG 会使 5Mg（OH）2-MgSO4-7H2O（相 517）的形成过程复杂化，延长其形成时间，但增加其含量和结晶尺寸。层状 M-S-H 凝胶和 517 相晶须之间的协同生长优化了孔隙结构，并使基体致密化，从而使 MOS 水泥的早期和后期机械强度提高了 40%-100%。将含有 SG 的 MOS 水泥浸入水中，残留的珍珠岩和青金石会转化为 M-S-H 凝胶。在 M-S-H 凝胶的形成速度超过青金石的形成速度以及青金石的消耗量超过其形成量的条件下，尽管 MOS 水泥浸泡在水中，但 SG 仍能使 MOS 水泥的机械强度和微观结构得到进一步发展。不过，只有当 SG 的用量在 5-10 wt.% 的范围内时，这种增强机制才会有效。

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引用次数: 0