Improved mechanical properties and piezoresistive sensitivity evaluation of MWCNTs reinforced cement mortars

Owing to their unique mechanical properties, multi-walled carbon nanotubes (MWCNTs) are considered to be one of the important reinforcing materials for the next generation of high-performance nanocomposites. Herein we present the reinforcing effect of highly dispersed multiwall carbon nanotubes (MWCNTs) on physico, mechanical and health sensing properties of cement mortars. The MWCNTs are effectively dispersed using a simple, facile method using ultrasonic energy. The compressive strength, water absorption properties and piezo-resistive stability of cement mortars reinforced with different concentrations (0, 0.2, 0.4, 0.6 and 0.8 wt.%) of multi-walled carbon nano-tubes (MWCNTs) were investigated in detail. The excellent reinforcing capabilities of the MWCNTs are demonstrated by the enhanced compressive strength. Additionally water absorption results show that with increase in concentration of MWCNTs water absorption decreases and optimum was found to be 0.4 wt.%. The piezo-resistive studies show that there is linear behaviour under static loads and the mortars reinforced with 0.4 wt.% MWCNTs exhibits better sensing properties under both static and cyclic loads. This result suggests that besides the benefits of the reinforcing effect, MWCNTs can also help in sensing health of cement mortars.