Novel approach to enhance the damping performance of cement-based materials through polymer/carbon nanotube composite coating and gradation of aggregates

A novel approach is introduced in this study to enhance the damping performance of cement-based composite materials. This improvement is achieved by the decoration of a viscoelastic layer, composed of carbon nanotube (CNT) and polyacrylate ester (PAE) composites, onto the surface of aggregates, combined with adjustments in aggregate gradation. The results demonstrate a remarkable 148 % increase in the loss factor of specimens with a minor composite coating dosage (10 mg/g) on aggregate surfaces compared to specimens prepared with plain aggregates. In the meantime, the 28-day compressive strength of the hardened specimens increased by 5.15 % with the composite coating, effectively addressing the mechanical property reductions observed in conventional methods. Microstructural and micromechanical analyses further revealed significant improvements in interfacial transition zone (ITZ) properties, attributed to enhanced frictional interfaces and the pull-out and fracture of CNT within the coating layer. These findings provide valuable empirical evidence to advance the development of cement-based materials with superior damping characteristics.