Mechanical and piezoelectric properties of ECC with CNT incorporated through fiber modification
Fan Yang, Shunzhi Qian
Abstract
This study investigated the effect of carbon nanotube (CNT) on the mechanical properties and piezoelectric properties of engineered cementitious composites (ECC) under tension. CNT was incorporated in the mixtures through two different methods including fiber coating and direct addition. The compressive strengths of CNT reinforced ECC are comparable to that of the ECC without CNT. The tensile strain capacity is greatly enhanced by 54% maximum attributed to the nanosized crack bridging capability of CNT. Moreover, CNT can effectively reduce the bulk electrical resistivity by 78% with only ~ 0.04 wt% of mixture addition. The piezoelectric properties of CNT reinforced ECC during tensile test were evaluated by calculating the gauge factor. CNT reinforced ECCs possess much higher gauge factor compared to the control group which indicates that their changes in electrical resistivity are more sensitive to the deformation. ECCs with CNT incorporated through direct addition method have higher gauge factor compared to fiber coating method because the electrical resistivity increase during crack formation is more significant in ECC with directly added CNT.