Effects of ageing and storage conditions on the interfacial bond strength of steel fibers in mortars

The ageing effects on the interfacial bond strength of steel fibers in cement mortars, under different storage conditions, were investigated by performing single fiber pullout tests. The bond strength rapidly increased until the 28 days water curing. After the water curing, the bond strength still monotonically increased if specimens were stored in air whereas it decreased if they were stored in water or 3.5% sodium chloride solution at the 120 days of age. The bond strength of fiber-mortars if they were stored in 3.5% sodium chloride solution was the lowest. Moreover, the addition of ground granulated blast-furnace slag in mortars, regardless of storage conditions, notably increased the bond strength.