Mechanical performance of The ITZ and mesoscopic compression failure mechanism of HPC with ASR inhibition measures under long-term brine corrosion

Effects of brine corrosion and Alkali-Silicate Reaction (ASR) on High Performance Concrete (HPC) incorporating ASR inhibition measures were investigated. The study involved developing HPC with ASR inhibition measures and exposing it to brine corrosion for a period of 10 years to investigate the compressive strength and mesoscopic mechanical properties within the Interfacial Transition Zone (ITZ) of coarse and fine aggregate in HPC. The results reveal that the microhardness of the ITZ surrounding alkali-active fine aggregate is the lowest due to the synergistic influence of ASR and brine corrosion. Additionally, the correlation between macroscopic and mesoscopic mechanical properties was established and macroscopic parameters for mortar and ITZ were derived. These parameters were subsequently used in the numerical computation of a three-dimensional mesoscopic mechanical model depicting the compressive strength of HPC cubes. The numerical simulation of the concrete mesoscopic mechanical model revealed that HPC with ASR inhibition measures, after prolonged exposure to salt lake brine corrosion, manifests mesoscopic mechanical characteristics in compressive failure within cube specimens. The propagation of cracks directly through the coarse aggregate results in a distinctive splitting failure pattern for the HPC specimens.