Enhancement of fracture toughness and mechanical properties of ultra-high performance concrete with ZnO nanoparticles under mixed-mode loading conditions: a multi-scale numerical investigation
    
Yazarlar (2)
Doç. Dr. Arzu ÇAĞLAR Kırşehir Ahi Evran Üniversitesi, Türkiye
Doç. Dr. Hakan ÇAĞLAR Kırşehir Ahi Evran Üniversitesi, Türkiye
Makale Türü Özgün Makale (SSCI, AHCI, SCI, SCI-Exp dergilerinde yayınlanan tam makale)
Dergi Adı Engineering Fracture Mechanics (Q1)
Dergi ISSN 0013-7944 Wos Dergi Scopus Dergi
Dergi Tarandığı Indeksler SCI-Expanded
Makale Dili İngilizce Basım Tarihi 10-2025
Cilt / Sayı / Sayfa 329 / 1 / 1–23 DOI 10.1016/j.engfracmech.2025.111626
Makale Linki https://www.sciencedirect.com/science/article/abs/pii/S0013794425008276?fr=RR-2&ref=pdf_download&rr=98e90bbc6a13f43f
Özet
This study is the first to thoroughly examine the effects of zinc oxide (ZnO) nanoparticles (NP) on fracture toughness, particularly in mixed-mode (I-II) conditions. It also pioneers the measurement of the impact of ZnO NP on the mechanical and fracture properties of Ultra-High Performance Concrete (UHPC). In order to simulate the behavior of ZnO nanoparticles in the UHPC matrix while taking into account different fracture modes (Mode I, Mode II, and mixed-mode I-II), the study presents a novel multi-scale finite element (FE) model. In order to improve the durability and performance of cementitious materials under complex loading scenarios, the study de- termines the ideal dosage of ZnO NP for increasing tensile strength and fracture toughness. The UHPC matrix behavior was simulated by the Concrete Damaged Plasticity (CDP) model, which was calibrated using experimental uniaxial compression and direct tension data. The fracture behavior of the UHPC specimens was examined using the Cracked Straight-Through Brazilian Disc (CSTBD) test configuration with different central crack inclination angles (β). The numerical model's validity was confirmed against experimental results for β = 0◦ and β = 45◦. A subsequent parametric study assessed the impact of ZnO NPs volume fraction and crack inclination angle on Mode I, Mode II, and mixed-mode (I-II) fracture toughness. Findings indicate that an optimal 0.4 wt% ZnO NPs addition significantly enhances mixed-mode fracture toughness, particularly at critical inclination angles dominated by combined tensile-shear mechanisms. While the optimal dosage for maximizing compressive strength was 0.6 wt% (yielding a 20.6 % increase), 0.4 wt% ZnO proved optimal for enhancing tensile strength (up to 40 % increase) and fracture toughness. Notably, at 0.4 wt%, the pure shear (Mode II) fracture toughness increased by over 2.1 times. This research highlights the substantial potential of ZnO NPs to improve UHPC mechanical properties and fracture resistance under complex, mixed-mode loading conditions.
Anahtar Kelimeler
Ultra-High Performance Concrete (UHPC), ZnO Nanoparticles, Fracture Toughness, Numerical Modeling, Brazilian Disc, Test Mechanical Properties