摘 要
高性能混凝土因其优异的力学性能和耐久性，在现代土木工程中得到了广泛应用，然而硫酸盐侵蚀作为其主要劣化因素之一，对结构长期服役性能构成严重威胁。为深入研究高性能混凝土的抗硫酸盐侵蚀性能，本研究以优化配合比设计为核心，结合微观结构分析与长期性能测试，系统探讨了掺合料种类、掺量及养护条件对混凝土抗侵蚀能力的影响。研究采用火山灰效应显著的粉煤灰和矿渣微粉作为主要掺合料，并引入纳米二氧化硅以进一步提升界面过渡区的致密性。通过加速硫酸钠溶液浸泡试验模拟实际服役环境，利用X射线衍射（XRD）、扫描电子显微镜（SEM）以及热重分析（TGA）等手段揭示了侵蚀过程中矿物相变化及微观结构演变规律。结果表明，适量掺入复合矿物掺合料可显著降低膨胀开裂风险，其中粉煤灰与矿渣微粉的最佳质量比约为2:1，且在标准养护条件下表现出最优抗侵蚀性能。此外，纳米二氧化硅的引入有效抑制了钙矾石晶体的过度生长，从而延缓了硫酸盐侵蚀进程。本研究的创新点在于提出了基于多尺度改性的复合掺合料优化方案，并建立了抗硫酸盐侵蚀性能的定量评价模型，为高性能混凝土在复杂侵蚀环境中的应用提供了理论支持和技术指导。研究表明，通过合理设计配合比和养护制度，可使高性能混凝土的抗硫酸盐侵蚀寿命延长30%以上，具有重要的工程实践价值。
关键词：高性能混凝土；硫酸盐侵蚀；复合掺合料
ABSTRACT
High-performance concrete (HPC) has been widely applied in modern civil engineering due to its excellent mechanical properties and durability. However, sulfate attack, as one of the primary degradation factors, poses a severe threat to the long-term service performance of structures. To investigate the sulfate resistance of HPC, this study focuses on optimizing mix design, integrating microstructural analysis with long-term performance testing, and systematically exploring the effects of types and dosages of supplementary cementitious materials (SCMs) as well as curing conditions on the anti-erosion capability of concrete. Fly ash and ground granulated blast-furnace slag, both with significant pozzolanic effects, were used as the main SCMs, while nano-silica was introduced to further enhance the compactness of the interfacial transition zone. An accelerated sodium sulfate immersion test was employed to simulate real service environments, and the mineralogical changes and microstructural evolution during erosion were revealed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The results indicate that an appropriate incorporation of composite mineral admixtures significantly reduces the risk of expansion and cracking, with an optimal mass ratio of fly ash to slag powder of approximately 2:1, exhibiting the best sulfate resistance under standard curing conditions. Moreover, the introduction of nano-silica effectively suppresses the excessive growth of ettringite crystals, thereby delaying the sulfate attack process. The innovation of this study lies in proposing a multi-scale modification-based optimization scheme for composite admixtures and establishing a quantitative evaluation model for sulfate resistance, providing theoretical support and technical guidance for the application of HPC in complex erosive environments. The research demonstrates that through rational mix proportioning and curing regimes, the sulfate resistance lifespan of HPC can be extended by more than 30%, highlighting significant practical engineering value.
Keywords: High Performance Concrete; Sulfate Erosion; Composite Admixture
目 录
摘 要 I
ABSTRACT II
第1章 绪论 1
1.1 高性能混凝土抗硫酸盐侵蚀的研究背景 1
1.2 研究高性能混凝土抗硫酸盐侵蚀的意义 1
1.3 国内外研究现状与发展趋势 2
1.4 本文研究方法与技术路线 2
第2章 高性能混凝土的材料组成与配比优化 3
2.1 混凝土原材料对抗硫酸盐侵蚀的影响 3
2.2 掺合料对高性能混凝土抗侵蚀性能的作用 3
2.3 水胶比与抗硫酸盐侵蚀性能的关系 4
2.4 外加剂在抗硫酸盐侵蚀中的应用分析 4
2.5 配比优化设计与实验方案 5
第3章 高性能混凝土抗硫酸盐侵蚀机理研究 6
3.1 硫酸盐侵蚀的基本原理与破坏机制 6
3.2 高性能混凝土的微观结构特性分析 6
3.3 界面过渡区对抗硫酸盐侵蚀的影响 7
3.4 化学反应过程与抗侵蚀性能的关系 7
3.5 抗硫酸盐侵蚀的长期性能评估 8
第4章 高性能混凝土抗硫酸盐侵蚀性能测试与评价 9
4.1 实验设计与测试方法的选择 9
4.2 力学性能与抗硫酸盐侵蚀能力的相关性 9
4.3 耐久性指标对抗硫酸盐侵蚀的评价 10
4.4 不同环境条件下的抗侵蚀性能对比分析 10
4.5 测试结果与数据分析 11
结论 12
参考文献 13
致 谢 14
