He Li, Peng Sheng, Jia Yong-Sheng, Yao Ying-Kang, Huang Xiao-Wu
Hubei Province Key Laboratory of Systems Science in Metallurgical Process, Wuhan 430065, China.
State Key Laboratory of Precision Blasting, Jianghan University, Wuhan 430056, China.
Materials (Basel). 2023 Oct 6;16(19):6573. doi: 10.3390/ma16196573.
In order to analyze the axial compressive properties of ultra-high-toughness cementitious composite (UHTCC)-confined recycled aggregate concrete (RAC), a batch of UHTCC-confined RAC components was designed and manufactured according to the requirements of GB/T50081-2002 specifications. After analyzing the surface failure phenomenon, load-displacement curves, scanning electron microscope (SEM), and parameter analysis of the specimen, the result shows that UHTCC-confined RAC is an effective confinement method, which can effectively improve the mechanical properties and control the degree of surface failure of RAC structures. Compared with the unconfined specimen, the maximum peak load of the UHTCC confinement layer with a thickness of 10 mm and 20 mm increased by 44.61% and 79.27%, respectively, meeting the requirements of engineering practice. Different fiber mixing amounts have different effects on improving the mechanical performance of RAC structural. The specific rule was steel fiber (SF) > polyvinyl alcohol fiber (PVAF) > polyvinyl alcohol fiber (PEF) > no fiber mixture, and the SF improves the axial compression properties of UHTCC most significantly. When there are strict requirements for improving the mechanical properties of the structure, SF should be added to UHTCC. On the contrary, PVAF should be added to UHTCC.
为分析超高性能水泥基复合材料（UHTCC）约束再生骨料混凝土（RAC）的轴向抗压性能，按照GB/T50081 - 2002规范要求设计制作了一批UHTCC约束RAC构件。通过分析试件的表面破坏现象、荷载 - 位移曲线、扫描电子显微镜（SEM）以及参数，结果表明UHTCC约束RAC是一种有效的约束方法，能有效提高RAC结构的力学性能并控制其表面破坏程度。与无约束试件相比，厚度为10mm和20mm的UHTCC约束层的最大峰值荷载分别提高了44.61%和79.27%，满足工程实际要求。不同纤维掺量对提高RAC结构力学性能的效果不同。具体规律为钢纤维（SF）＞聚乙烯醇纤维（PVAF）＞聚乙烯纤维（PEF）＞无纤维掺合，且SF对提高UHTCC轴向抗压性能的作用最为显著。当对提高结构力学性能有严格要求时，应在UHTCC中添加SF。相反，应在UHTCC中添加PVAF。
