A micromechanical crack bridging model considering the slip-softening interface with the residual shear stress for SFRCC

Abstract

Characterizing the bond properties of the steel fiber/matrix interface plays an important role in describing the crack bridging effect in steel fiber-reinforced cementitious composites (SFRCC). In this paper, a new interface law considering the residual shear stress is proposed to interpret the slip-softening effects of the steel fiber/matrix interface. Accordingly, a micromechanical crack bridging model for SFRCC is formulated by combining the single steel fiber pullout model with the image analysis-based fiber orientation distribution. Comparisons with the experimental data and the existing models show that the proposed model can well predict SFRCC’s tensile softening behavior. Meanwhile, the decrease rate of the bridging stress, the composite fracture energy, the peak bridging stress and the corresponding peak crack opening displacement (COD) are employed to quantitatively evaluate the crack bridging curves. Finally, the effects of the residual shear stress ratio, the interfacial softening coefficient and the fiber orientation distribution on the crack bridging relation are discussed with the proposed framework.

Elastic moduli prediction of a short fiber composite with interface debonding at fiber ends

“…On the other hand, the interfacial debonding at the fiber end can be regarded as a fracture in the matrix regardless of the fiber. The matrix fracture can be modeled as a void nucleation followed by growth (Bonfoh and Lipinski, 2007; Wang et al., 2012; Zaïri et al., 2008) or be characterized by fracture energy dissipation (Wei et al., 2023). For a particle composite, a debonding-induced reduction in load-bearing capacity can be evaluated by a damage variable that depends on the cracking angle.…”

A resilience assessment framework for microencapsulated self-healing cementitious composites based on a micromechanical damage-healing model

“…There is no doubt that the research on resilience at the material level will become a research hotspot in the field of materials. Concrete structures built with self-healing materials have self-healing properties after disaster damage, and research on this aspect can improve the safety and sustainability of the entire life cycle of underground structures (Chen et al., 2021; Ivica et al., 2022; Tian et al., 2019; Voyiadjis et al., 2020; Wei et al., 2023; Zhang et al., 2022; Zhu et al., 2021). Based on different healing methods, many healing materials have been proposed by different scholars, such as the microencapsulated self-healing concrete (Andrushia et al., 2020a, 2020b; Jahadi et al., 2023; Zhou et al., 2020; Zhuang et al., 2021), the UHPC (Fang et al., 2022; Luo et al., 2019; Zhu et al., 2022), the slurry infiltrated fiber concrete (Zhou et al., 2023), the lightweight aggregate concrete (Xiong et al., 2019, 2022a, 2022b), the calcined wollastonite powder (Zheng et al., 2021), the ECC (Zhou et al., 2020) and the bacteria-based concrete (Zhuang and Zhou, 2019).…”