ZIF-67 Metal Organic Frameworks Modified Ultra-High Performance Concrete: Enhancement of Compressive and Flexural Strength

To improve the flexural and compressive strength of ultra-high-performance concrete (UHPC), the authors of the present study synthesized metal–organic frameworks (MOFs), primarily zeolitic-imidazolate frameworks (ZIFs) like ZIF-67. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FE-SEM) are used to first characterize the synthesized ZIF-67 and establish its crystalline structure, functional groups, and shape. Additionally, ZIF-67 nanoparticles are exfoliated and introduced to UHPC in varying concentrations to study its impact on the material’s compressive and flexural strength. Based on the strength increase criterion, the optimal concentration for ZIF-67 in the ultra-high performance trials was between 0.4 and 0.7%. The XRD and FE-SEM findings were complementary to one another.