Towards new generation of electrode-free conductive cement composites utilizing nano carbon black

Abstract

Development of a scalable, low-cost conductive concrete with a long lifetime has the potential to evolve into a new solution for the next generation of floor heating systems. This work systematically investigates the performance of nano carbon black (NCB) cement composite as a viable candidate for floor heating. To this end, its conductivity and joule heating properties are adjusted by changing the weight percent of cheap and affordable NCB. The percolation transition zone is in the 10%-12.5% range for electrode-free specimens, where electrical resistivity sharply drops and the AC conductivity and joule heating significantly increase. Micro-model numerical simulation also confirms temperature rise in samples with NCB contents beyond the percolation threshold. Surprisingly, it is shown that the mechanical strength of the conductive composite developed in this work can remain at a satisfactory level.