Effect of graphite nanoparticles on strength and carbonation performance of cement mortar

Strength and carbonation performance are two main concerns in porous cementitious materials exposed to the atmosphere with an increasing concentration of CO2. Carbon-based reinforcers have been widely investigated in recent decades. However, practical applications have been impeded by their high cost. In this paper, inexpensive graphite nanoparticles were used to improve cement mortar. The compressive strength and carbonation performance were evaluated. XRD and SEM-EDX tests were conducted to further analyse the mechanisms. The results showed that the effects of graphite nanoparticles differed in dosage. The addition of graphite nanoparticles in the amount of 0.5% by mass significantly enhanced the performance against carbonation, while slightly worsened the compressive strength. On the contrary, 1.0% addition enhanced both the performance against CO2 penetration and strength of cement mortar after carbonation.