Effect of Mixing Steel Dust and Shred-Like Steel Fibres on the Properties of Concrete

Abstract

In this research, fine and coarse aggregates present in the concrete are replaced with steel dust and shred-like steel fibres, respectively in different ratios and its effect on the properties of concrete is studied. Eight batches of concrete were mixed, each with the mix proportion of 1:2:4 and water cement ratio of 0.52. Batch A was of normal concrete. In batches B, C, and D, 5%, 10%, and 15% of sand was replaced with steel dust. In batches, E, F, and G, 2%, 5%, and 8% of coarse aggregate were replaced with steel fibres. In the last batch H, both 5% of sand and 5% of coarse aggregate were replaced with steel fine and steel fibres respectively. British as well as American standards were followed during the research. Slump test was performed in a fresh state of each mix to find the effect of these replacements on workability. 12 cubes of 150mm x 150mm x 150mm for compressive strength test and 12 cylinders of 150mm diameter and 300mm height of each, for tensile strength test were made for each batch to check these strength after 3, 7, 14, 28 days. It was found that the workability of fresh concrete decreases while density of fresh as well as hardened concrete increases with these replacements. It also results in an increase in initial compressive strength and a decrease in final compressive strength as compared to those of normal concrete. As far as tensile strength is concerned an increase in initial as well as final strength was observed.