Influence of graphite nano/micro platelets on the residual performance of high strength concrete exposed to elevated temperature

•High temperature mechanical, durability and fracture properties of GNMPs reinforced concrete are presented.•Properties of the modified matrices show promise.•Microstructural study showed adequate dispersion of GNMPs in cement paste matrix.•Energy absorption capacity of modified matrices improved manifolds, which helps mitigate spalling. An experimental program was designed to investigate the residual properties of high strength concrete (HSC) modified with different percentages of graphite nano/micro platelets (GNMPs) after exposure to elevated temperature. Mechanical properties such as compressive and tensile strength, stress–strain response, elastic modulus and mass loss have been studied at elevated temperature in 23–800 °C range. Non-destructive testing technique such as ultrasonic pulse velocity (UPV) was used to investigate the quality of concrete in the post fire exposure. Further, the energy dissipation characteristics have also been observed in detail. Scanning electron microscopy (SEM) was used for the study of morphological changes such as crack formation, microstructural damage and the dispersions of GNMPs. Results showed better retention of mechanical and physical properties of high strength concretes containing GNMPs. Data obtained was utilized to formulate mathematical relationships for expressing mechanical, durability and energy related properties of HSC modified with different percentages of GNMPs as a function of temperature.