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

Abstract

This research aims to study the 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) and hooked-end steel fiber (length of 35 mm) were used in concrete at the rates of 0.5 and 1.0% by volume. Binder content of concrete was kept a constant of 600 kg/m³ and 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 by using superplasticizer. The compressive strength, modulus of elasticity, flexural strength, and creep strain of concrete were investigated. The results revealed that the compressive strength at 28 days of high performance concrete containing 70% GBA with 1.0% hooked-end steel fiber was up to 80.4 MPa. 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.