Enhancing the mechanical performance of plastering mortars with low levels of multilayer graphene and their chemical, structural, and microstructural characteristics

The present work investigated the impact of low levels of graphene incorporation into plastering mortars. The presence of graphene proved beneficial in various properties, as it can increase the area and specific surface of composites and accelerate the hydration process, facilitating the formation of hydrated calcium silicate gels. Specifically, adding 0.06% graphene led to a 15% increase in axial compression strength and an 18% improvement in flexural tensile strength. Low levels of graphene correlate with increased hydration, resulting in better expansion and shrinkage performance. SEM examinations demonstrated that reference mortar showed numerous microcracks that affected their mechanical behavior. In addition, plastering mortars containing 0.03% and 0.06% graphene show smaller pore sizes and higher crystal densities, which improved cohesion and void filling. However, increasing graphene concentrations beyond 1%, led to particle dispersion. This dispersion did not enhance the binder's hydration process, impeding chemical interactions among the cement gel crystals. In summary, this work highlights the potential benefits of controlled graphene incorporation for optimizing plastering mortar properties, emphasizing the importance of finding the right balance to harness its advantages without compromising performance. •Low levels of graphene in plastering mortars enhance the mechanical performance.•Adding more than 1% of graphene nanoparticles leads to fine particles' dispersion.•Incorporate graphene quantity is proportional to the degree of hydration in mortars.•Low levels of graphene increase the modulus of elasticity and mechanical resistance.•High level of graphene nanoparticles is related to the occurrence of microcracks.