Development of Nanocarbon Black-enabled Self-strain Sensing Ultra-high-performance Cementitious Composites

Abstract

In this study, nanocarbon black (nCB) is employed to make the matrix of UHPC conductive. The nCB-UHPC composite is investigated for its fresh and hardened mechanical properties, piezoresistive behavior and microstructure. Piezoresistive behavior and strain sensitivity are measured by fractional change in electrical resistivity (FCR) with applied stress/strain. The nCB-UHPC composite exhibits adequately good workability (slump spread ≥ 170 mm), compressive strength of more than 144 MPa and an outstanding sensitivity (gauge factor > 130) achieved with 1.5% nCB. Additionally, it has shown a repeatable, highly sensitive compressive strain response up to 40 MPa. The proposed high-sensitivity nCB-UHPC composite demonstrates significant potential in becoming a field-deployable solution for the health monitoring of concrete infrastructure.