高强高延ECC力学性能:基体、纤维及界面影响研究进展

Research progress on the mechanical properties of high-strength high-ductility ECC: effects of matrix, fibers, and interface

  • 摘要: 高强度高延性水泥基复合材料(HSHD-ECC)因其卓越的力学性能而在土木工程领域引起广泛关注。本文综述了近年来HSHD-ECC的研究进展,从基体、纤维、纤维-基体界面三个方面探讨其对HSHD-ECC静态、动态力学性能的影响机制,解析实现高强度高延性双赢目标的本质。首先,基于致密颗粒堆积理论总结了惰性、活性辅助胶凝材料及可替代性骨料对基体的增强效益;其次,通过纤维掺量、长细比、类型三个影响因子归纳分析其对HSHD-ECC力学性能的影响机制,针对不同混合模式提出了相应的参考设计范围:纤维混合的总体积量通常控制在1.5%-2.5%之间,其中PE纤维掺量通常在1%-1.5%,ST掺量低于1%;最后,基于不同基体组分和纤维因素对拉拔行为的影响,结合裂纹桥接预测模型剖析界面特性。本文研究结果可为HSHD-ECC的多性能目标优化设计提供参考借鉴。

     

    Abstract: High-strength high-ductility engineered cementitious composites (HSHD-ECC) have attracted extensive attention in the field of civil engineering due to their outstanding mechanical properties. This paper reviews recent research progress on HSHD-ECC and discusses the mechanisms by which the matrix, fibers, and fiber-matrix interface influence its static and dynamic mechanical properties, thereby elucidating the essential principles for achieving the dual objectives of high strength and high ductility. First, based on the theory of dense particle packing, the strengthening effects of inert and reactive supplementary cementitious materials as well as alternative aggregates on the matrix are summarized. Second, the influence mechanisms of fiber volume fraction, aspect ratio, and fiber type on the mechanical properties of HSHD-ECC are systematically analyzed, and corresponding reference design ranges are proposed for different mixing modes: The total volume fraction of hybrid fibers is generally maintained 1.5%–2.5%. PE fibers is designed to be 1%–1.5%, while ST fibers is limited below 1%. Finally, considering the effects of different matrix components and fiber parameters on fiber pull-out behavior, the interfacial characteristics are analyzed in combination with crack-bridging prediction models. The results of this review provide useful references for the multi-performance optimization design of HSHD-ECC.

     

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