Experimental and numerical simulation study on the mechanical properties of steel fiber-UHPC interface

This study aims to investigate the interfacial mechanical attributes between steel fiber and the ultra-high performance concrete (UHPC) matrix. A comprehensive analysis was conducted on the pull-out process of steel fiber from the UHPC matrix, utilizing both experimental and numerical simulation methods. Factors such as fiber embedding depth, fiber diameter, and embedding angle and their potential impacts on the mechanical properties of the fiber-UHPC interface were examined. The results show that in the fiber pull-out test, the maximum pull-out force of the embedded depth group shows a trend of rapid rise and then slow development, and the pull-out work increases with the increase of the embedded depth. The maximum pull-out force and pull-out work of the fiber diameter group increase with the increase of the fiber diameter. The maximum pull-out force and pull-out work of the embedded angle group increased first and then decreased with the increase of the angle. The peak load reached 72.5 N when the embedding angle was 45 degrees, and the maximum pull-out work reached 214.4 N <middle dot> mm when the embedding angle was 30 degrees. The finite element simulation results are in good agreement with the experimental results.