The present study investigates the experimental characterization of cementitious materials combined with four different carbon nanofillers; multi walled carbon nanotubes (MWCNTs), carbon nanofibers (CNFs), carbon black (CB) and graphene nanoplatelets (GNPs). Measurements of thermal conductivity and thermal diffusivity were carried out using the Transient Plane Source (TPS) technique. MWCNTs were found to influence thermal conductivity when they were aligned, compared to randomly distributed. GNP paste exhibited the highest thermal conductivity....