Mechanical and stress-sensitive properties of multi-walled carbon nanotubes reinforced cement matrix composites

摘要

Multi-walled carbon nanotubes(MWNTs)reinforced cement matrix composites(MWNTRC)are successfully mixed using physically ultrasonic mixing and chemically cetyltrimethyl ammonium bromide(C16TAB)surfactant.Microstructures reveal that most of MWNTs can be encapsulated and compatible with cement hydration products.Mechanical results show the maximal enhancements of the flexural and subsequent compressive strength of the MWNTRC,compared with that of the plain mortar,are 17.00% and 28.3%,respectively.A simple DC series-wound circuit is employed joining to LMS instruments,collecting the voltage signals with four-electrode method,and the pressure transducer signals to investigate the stresssensitive properties of the MWNTRC.Results show that the relative resistivity of MWNTRC steadily falls down both in its pressure elastic and inelastic range; whereas the relative resistivity is the steadily increasing trend for the plain mortar without MWNTs.These stress-sensing attributes and mechanical improvements can develop the MWNTRC into a promising candidate sensor for structure health monitoring.