Response assessment under dynamic loading and microstructural investigations of rubberized concrete

Dynamic loading may severely compromise the functional performance of concrete. The present study examined the effects of the partial replacement of fine aggregates with rubber ash (0, 5, 10, 15, and 20%) and hybrid rubber waste (0, 5, 10, 15, 20, and 25% of rubber fiber with 10% constant rubber ash) on the response of concrete to impact and fatigue loading. Impact performance of the resulting concrete was examined using a drop weight test, flexural loading test, and rebound test. Fatigue performance was assessed using a servo-hydraulic fatigue machine. Regression analysis to establish a relationship between different impact tests was carried out. A two-parameter Weibull distribution was used to analyze the results of the drop weight and fatigue tests to facilitate ease of analysis. Scanning electron microscopy (SEM) and optical microscopy were deployed to investigate the microstructural attributes of the rubberized concrete. It was found that the incorporation of rubber ash and rubber fiber in concrete led to enhanced resilience toward impact and fatigue loading.