Development of self-sensing cementitious composite incorporating hybrid graphene nanoplates and carbon nanotubes for structural health monitoring

Abstract

The safety of civil infrastructures is threatened due to aging and aggressive environments. Thus, the quest for structural health monitoring (SHM) on the safety of civil infrastructures is perpetual, and rational design of sensors for SHM is crucially desired. Due to superior mechanical properties and electrical conductivity as well as the synergistic enhancing effect of 2D graphene nanoplates (GNPs) and 1D carbon nanotubes (CNTs), a self-sensing cementitious composite with excellent properties by addition of hybrid GNPs/CNTs is developed. The compressive strength of cementitious composite is decreased but still can reach 66.0 MPa as 6 wt% GNPs/CNTs is added. Simultaneously, electrical resistivity of cementitious composite is decreased by two orders. The absolute maximum fractional change in electrical resistivity (FCR) under cyclic and monotonic compression is up to 9.86% and 12.79%, respectively. Meanwhile, stress and strain sensitivity can achieve 0.49%/MPa and 86.03, respectively. Loading rates almost have no effect on piezoresistivity, but sensitivities decrease with increasing loading amplitudes. The self-sensing cementitious composite containing hybrid GNPs/CNTs is expected to be applied as sensors for SHM on the safety of civil infrastructures.