Effects of Steel Fibers on Mechanical Properties and Creep of High Performance Concrete Containing Ground Coal-Bottom Ash

This research aims to study mechanical properties and creep of steel fiber reinforced high performance concrete containing ground coal bottom ash (GBA). A very fine bottom ash, particles retained on a No.325 sieve less than 1% by weight, was used to partially replace ordinary Portland cement at a rate of 70% by weight of the binder. In addition, straight steel fiber (length of 13 and 20 mm) was used in concrete at the rate of 0.5 by volume and hooked-end steel fiber (length of 35 mm) wasused at the rates of 0.5 and 1.0% by volume. Water to binder ratio of 0.27 was used. The slump flow was controlled between 650-750 mm and time at a flow diameter of 500 mm was maintained between 5-20 seconds. The results revealed that the high performance concrete containing 70% GBA with 1.0% hookedend steel fiber could develop the compressive and flexural strength up to 80.4 and 10.2 MPa at 28 days, respectively. The flexural strength and toughness of concrete were significantly improved with the fiber length. Moreover, the creep strain of concrete was reduced with the increase of fiber content.