Effects of silica fume and steel fibers on some mechanical properties of high-strength fiber-reinforced concrete

There are many test methods to measure the impact resistance of fiber-reinf orced concrete that are complicated, time consuming, and expensive. A pract ical test method has been developed to measure the impact resistance of hig h-strength fiber-reinforced concrete (HSFRC). The equipment developed can a lso be used for testing aggregate impact values by simply changing the base plate of the machine. A machine was developed to measure the surface abras ion resistance of HSFRC. Testing fiber-reinforced concrete for surface abra sion resistance was found to be extremely difficult if realistic and practi cal results were desired. In this study the influence of silica fume on the properties of HSFRC was investigated by using silica fume at two different percentages and with three different hooked-end fibers, namely, 30/0.50, 6 0/0.80, and 50/0.60 length/diameter (mm/mm). Fibers were added to concrete in three different percentages of 0.5, 1.0, and 2.0% by volume of concrete. The results show that including fibers in high-strength concrete improves impact resistance, surface abrasion, and splitting tensile strength.