Effect of Graphene Nanoplatelet on the Carbonation Depth of Concrete under Changing Climate Conditions

Abstract

Climate change has been unprecedented in the past decades or even thousands of years, which has had an adverse impact on the mechanical properties of concrete structures. Many researchers have begun to study new concrete materials. Graphene nanoplatelet (GNP) is an attractive nanomaterial that can change the crystal structure of concrete and improve durability. The aim of the present study was to investigate the effect of GNP (0.05%wt) on the carbonation depth of concrete under simulated changing climate conditions (varying temperature, relative humidity, and carbon dioxide (CO2) concentration), and compare it with ordinary concrete. When the concentration of CO2 is variable, the carbonation depth of graphene concrete is 10% to 20% lower than that of ordinary concrete. When the temperature is lower than 33 °C, the carbonation depth of graphene concrete is less than that of the control sample; however, above 33 °C, the thermal conductivity of GNP increases the carbonation reaction rate of concrete. When the humidity is a variable, the carbonation depth of graphene concrete is less than 15% to 30% of ordinary concrete, and when the humidity is higher than 78%, the difference in the carbonation depth between the ordinary concrete and the graphene concrete decreases gradually. The overall results indicated that GNP has a favorable effect on anti-carbonation performance under changing climate conditions.