Application of self-sensing cement-stabilized sand for damage detection

Abstract

The sensing ability induced by carbon nanomaterials has attracted considerable attention in the scientific community for use in cement and concrete. However, the application of carbon nanomaterials in stabilized soils has been scarce. Therefore, in this study, the use of multiwalled carbon nanotubes (MWCNTs) and graphene nanoplates (GNPs) in cement-stabilized sand was investigated. MWCNTs and GNPs not only improve the mechanical characteristics of cement-stabilized sand but also can change conventional cement-stabilized sand into an intrinsic self-sensing material, which is important for structural health monitoring (SHM). The proposed composite was submitted from small to large stresses under cyclic loading to detect strain, cracks, and damage. To identify different levels of damage, various macro- and microscale analyses were carried out to explain the composite self-sensing ability. The key results used in the analysis were from the fractional changes in resistivity (FCR) and digital image correlation (DIC) and scanning electron microscope (SEM) measurements. These results demonstrate the capability of the proposed MWCNT/GNP cement-stabilized sand for detecting the strain, stress, and damage of materials through different self-sensing trends in the elastic and plastic regions. It is very important to monitor the serviceability of a composite in a real structure through different self-sensing trends in the elastic and plastic regions.