Temperatures and moisture contents effects on the resistance and self-sensing properties of carbon nanofiber cement-based mortar

3^rd International Conference on Smart Materials & Structures

March 20-22, 2017 Orlando, USA

Hui Wang, Xiaojian Gao and Qinlin

Harbin Institute of Technology, China

Posters & Accepted Abstracts: J Material Sci Eng

Abstract :

Effects of temperature and moisture content on electrical and piezoresistive properties of carbon nanofiber mortar (CNFM) were researched. Electrical resistivity of CNFM in different temperatures and moisture contents with w/c ratio 0.4 were experimentally determined. The CNFM used to study the environmental effects on resistance were reinforced with well dispersed carbon nanofibers in amounts from 0% to 2.5% by volume of cement. Piezoresistivity of CNFM with 1.5 vol.%, 2.0 vol.% and 2.5 vol.% of CNFs were determined at 20 oC with the specimens dried at 60 oC for three days before testing. Piezoresistive properties of CNFM including 2.5 vol.% of CNFs were investigated at different temperatures and moisture contents. Results indicated that the baseline of electrical resistivity shifted with the surrounding environments. The electrical resistance of CNFM incorporating different loadings of CNFs varied in different laws with temperatures under saturated and dry-out state. CNFM with 2.5 vol.% of CNFs (M25) shows the best sensitivity when tested at dry-out state at 20 oC. Piezoresistivity of M25 had almost no variation with moisture contents when the temperature was lower than -5 oC. M25 at 0% moisture content performed the best sensitivity of all moisture contents. The dry-out state at 20 oC was the most favorable environment for the piezoresistive properties of CNFM.

Biography :

Email: gaoxj@hit.edu.cn