Tensile properties of cracked reactive powder concrete in corrosive environment - effects of crack width and exposure duration

The combined effect of the pre-crack width and exposure duration in a corrosion environment on the tensile properties of reactive powder concrete (RPC) was investigated. For this purpose, singly cracked RPC was exposed to a standard 3.5% sodium chloride (NaCl) solution. The tensile performance of pre-cracked RPC was deteriorated by severely corroded steel fibers when a wide crack width and long exposure duration were applied. No performance deterioration was observed in the pre-cracked RPC at a width of 0.02 mm (20 μm) up to an exposure duration of 20 weeks, and the surface oxidation degree of steel fibers was also minor. However, the tensile strength decreased after 20 weeks of exposure when the crack width was 0.05 mm (50 μm) or greater. The wider crack width generally accelerated the performance deterioration when exposed to the corrosion environment. Some of the samples with crack widths of 0.3 and 0.15 mm exhibited an increase in tensile strength after exposure to the NaCl solution for 4 or 10 weeks owing to the moderately corroded steel fibers but showed a decrease in strength with a longer exposure duration.