ELECTRICAL RESISTANCE OF HYBRID STEEL FIBER REINFORCED SELF- COMPACTING CONCRETE

Abstract

Concrete has high compressive strength as well as very low conductivity. In this study, the effect of long and short steel fibers on electrical resistivity, conductivity and temperature rise of self-compacting concrete (SCC) was investigated depending on fiber combinations (single and binary hybrid) and length of the short steel fibers (6 and 13 mm). For this purpose, four mixtures were designed: non-fiber reference, a single fiber-reinforced mixture with only long fibers and two hybrid steel fiber-reinforced mixtures with long and 6mm or 13 mm short steel fiber. Also, all steel fiber-reinforced mixtures contain a total of 1% steel fiber by volume. The workability tests of slump-flow, t500 and J-ring height difference were performed by the EFNARC. The samples were cured for 90 days and then, mechanical properties and electrical resistivity of samples were determined. Finally, the inclusion of steel fiber into SCC dropped the electrical resistivity and thus, increased its conductivity. In addition, hybrid fiber-reinforced SCC samples had the lowest electrical resistivity and highest conductivity and temperature rise. Also, 13 mm long micro steel fiber having high slenderness had a more positive effect on the electrical properties of concrete than 6 mm micro steel fiber.