Effect of Addition of Steel Fiber on the Compressive Strength of Composite Concrete Materials under High Temperatures (Experimental & Statistical Work)

Abstract

This study presents the benefit gained from using steel fiber reinforcement on concrete mixture. The effect of fire on compressive strength is investigated. Two different tests, one of them is the non destructive test which is the ultrasonic pulse velocity (UPV) test and the other is the destructive compression test, are carried out using (10cm) cubs.
Forty-eight cubes (half of them are with steel fiber reinforcement of fiber/concrete ratio of (0.01) by volume and the remaining cubes are without fiber reinforcement) are heated to temperature levels of (100,200,300,400,500,600 and 700°C). Then after specimens are air cooled and (UPV) test is done, the specimens are destructively tested.
The results indicated that the addition of steel fiber increases the compressive strength at all tested heating levels with a maximum percentage increase of (56.9%) at temperature level (500°C) in spite of that they have the same behavior but the residual compressive strength decreases with the addition of steel fiber for the tested heating levels lower than (400°C) and increases for the heating levels above this degree.