Workability and Flexural Strength of Recycled Aggregate Concrete with Steel Fibers

Abstract

This study examined how concrete workability and flexural strength are affected by steel fibers and recycled aggregates. Steel fibers were used in doses between 1-5%, with an increment of 0.5%, and 50% of the natural coarse aggregates were replaced by recycled. Two mixes of conventional and recycled aggregate concrete without steel fibers were used as control mixes. Concrete mixes were prepared using 1:2:4 and 0.45 water-to-cement ratios. Workability was determined using the slump cone. Three prism specimens sized 500×100×100mm were prepared for each batch and cured for 28 days in potable water. After curing, the specimens were air-dried in the laboratory and tested to evaluate their flexural strength under two-point loading. The load and deflection were monitored at regular intervals until failure. A comparison of results with control mixes showed that as the percentage of steel fiber increased, flexural strength increased by 69% and deflection decreased by 66%. The use of steel fibers improved the flexural strength of the recycled aggregate concrete by 59%.