机制砂特性对自密实混凝土力学与工作性能影响的研究进展

Research Progress on the Effects of Manufactured Sand Characteristics on the Mechanical Properties and Workability of Self-Compacting Concrete

摘要: 天然砂资源的匮乏与环保政策的收紧，推动了机制砂在混凝土行业的全面应用。自密实混凝土(SCC)凭借其卓越的填充性与施工性能，在复杂工程结构中极具应用前景。将机制砂引入SCC配制(MS-SCC)，是实现资源可持续化与工程高性能化的关键路径。然而，机制砂在颗粒形貌、级配断档、石粉含量及母岩岩性等方面与天然砂存在本质差异，深刻影响着MS-SCC的流变特性与硬化性能。本文基于国内外最新研究进展，系统综述了机制砂特性(形貌、级配、石粉)及配合比关键参数(水胶比、砂率、外加剂)对MS-SCC工作性能(流动性、间隙通过性)与力学性能(强度、模量、抗裂性)的影响规律及作用机理。结论表明，通过优选机制砂品质、精准调控石粉含量、优化浆骨比例并协同高效外加剂，可制备出满足高标准工程要求的MS-SCC。本文旨在为该领域的配合比设计优化与工程应用提供理论依据。

Abstract: The increasing shortage of natural sand resources and the tightening of environmental protection policies have made the application of manufactured sand (MS) in concrete an inevitable choice for the green development of the industry. Self-compacting concrete (SCC) demonstrates significant advantages in modern complex engineering structures due to its excellent construction performance and compactness. The application of manufactured sand in the preparation of SCC (MS-SCC) is a key technical path to balance resource sustainability with high performance. However, manufactured sand differs fundamentally from natural sand in terms of particle morphology, gradation characteristics, stone powder content, and parent rock lithology. These characteristics profoundly affect the comprehensive performance of MS-SCC. Based on current research progress, this paper systematically reviews the influence laws and mechanisms of MS characteristics (particle morphology, gradation, stone powder content) and key mix proportion design parameters (water-binder ratio, sand ratio, cementitious material system, admixtures) on the workability (flowability, filling ability, passing ability) and mechanical properties (compressive strength, elastic modulus, crack resistance) of MS-SCC. The conclusions indicate that MS-SCC meeting high-standard engineering requirements can be successfully prepared by selecting high-quality MS raw materials, scientifically controlling stone powder content, optimizing mix proportion design (especially water-binder ratio and sand ratio), and synergistically using high-efficiency admixtures and mineral admixtures. This article aims to provide a systematic theoretical reference for in-depth research and engineering applications in this field.