For the ultra-high performance concrete (UHPC) overlaying normal concrete (NC) structures subjected to high-temperature burning, the reliable interface performance between UHPC and NC is the foundation for achieving their good co-work behavior. This paper focused on experimental and theoretical research on crack propagation at the interface of these UHPC-NC configurations under stress waves. A bi-material notched semi-circle bend (BNSCB) configuration was proposed, and the impact experiments were conducted on the BNSCB specimens using a split Hopkinson pressure bar system (SHPB). Three temperatures (20℃, 100℃, and 300℃) were designed in this test, examining the interfacial impact performance of the BNSCB specimen subjected to the high-temperature burning. Based on the finite element method and crack propagation gauge, the dynamic fracture toughness at the crack tip of the interface of the BNSCB specimen was calculated. The results show that: (1) the values for the untreated BNSCB specimens increased by 23.3% and 22.6%, respectively, compared to the heat-treated BNSCB specimens. (2) the parameter at the crack tip of the BNSCB specimen is much smaller than , and the parameter plays a dominant role in crack initiation; (3) with the increase in loading rate from 580 GPa/s to 740 GPa/s, both untreated and heat-treated BNSCB specimens show significant improvement in the parameters and , with a more pronounced improvement observed in untreated compared to heat-treated BNSCB specimens.

中文翻译：

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高温灼烧处理后UHPC-NC试件动态断裂实验研究

对于承受高温燃烧的超高性能混凝土（UHPC）覆盖普通混凝土（NC）结构来说，UHPC和NC之间可靠的界面性能是实现其良好协同工作性能的基础。本文重点关注应力波作用下 UHPC-NC 结构界面裂纹扩展的实验和理论研究。提出了一种双材料缺口半圆弯曲（BNSCB）配置，并使用分体式霍普金森压力杆系统（SHPB）对BNSCB样品进行了冲击实验。本试验设计了3个温度（20℃、100℃、300℃），考察BNSCB试件在高温燃烧下的界面冲击性能。基于有限元方法和裂纹扩展计，计算了BNSCB试件界面裂纹尖端的动态断裂韧性。结果表明：（1）与热处理的 BNSCB 样本相比，未经处理的 BNSCB 样本的值分别增加了 23.3% 和 22.6%。 (2) BNSCB试件裂纹尖端处的参数远小于 ，且该参数对裂纹萌生起主导作用； (3) 随着加载速率从 580 GPa/s 增加到 740 GPa/s，未处理和热处理的 BNSCB 试件的参数 和 均表现出显着的改善，与热处理的 BNSCB 相比，未处理的改善更为明显标本。