Abstract
This research investigates the effect of hematite powder on the properties of high-strength fiber-reinforced concrete, such as compressive strength, tensile strength and modulus of elasticity. Different types of steel fiber have been used in this study, end hooked steel fiber and corrugated steel fiber, and hematite powder API. The study was conducted through two stages. The first stage is to find and verify the ratio and type of steel fiber that can give the highest improvement in the properties of the concrete. The ratios 0.5%, 1% and 1.5% end hooked steel fiber,1.5% of corrugated steel fiber, and 1.5% of mixed steel fiber (50% end hooked and 50% corrugated) have been used. The second stage was conducted to find the best ratio of hematite powder can be added as a cement replacement to enhance the properties of the high-strength fiber-reinforced concrete. Six percentages of hematite 0.5%, 1%, 1.5%, 2.5%, 3.5% and 5% were used. The results showed that using hematite powder ratio of up to 2.5% with mixed steel fiber led to an enhancement of the properties of the concrete, where the increment was 27.5% and 41.3% for compressive and tensile strength, respectively, and the modulus of elasticity was increased by 11.4%.