Electrical and microstructural analysis of UHPC containing short PVA fibers

Steel fibers are the most widely used fibers in making Ultra-high performance concrete. Under extreme weather conditions the embedded steel fibers may be corroded and the risk of serious deterioration will be high. Moreover, while the influence of steel fibers has been thoroughly studied, the addition of synthetic fibers and their effect on properties of UHPC has not completely investigated throughout the years. In this paper, mix proportions containing different volume percentages of PVA fibers were fabricated. Mechanical, electrical and microstructural properties were evaluated. Results showed that unlike steel fibers, chloride diffusion and penetration are reduced by the addition of PVA fibers. Different fractions of cement were replaced with silica fume to determine the optimum value by processing the scanning electron microscope images and Energy Dispersive Spectroscopy analysis. SEM and EDS analysis indicated that a uniform cement paste with a Ca/Si ratio of near 1 which means a harder matrix is obtained when the replacement ratio of silica fume increases. (C) 2019 Elsevier Ltd. All rights reserved.