Sheelan M. Hama Al – Barazinji
This research includes a study of the effect of adding steel fibers extracted from old tires from cars (which are now available in abundance in Iraq) to polymer concrete. The efficiency of these fibers is compared with imported fibers. These two types of fibers were added with percentages of concrete volumes. These percentages were (1%), (1.5%) and (2.0%). Reference concrete mix without fibers was also made for comparative purposes. Results proved that adding steel fibers with these percentages, regardless of their source, lead to improvements in all tested properties of concretes in comparison to concrete samples without fibers. The results were compared with conventional concrete. It was observed that concrete specimens with steel fiber (regardless of its type) increased its compressive strength approximately by 3-15%, its splitting tensile strength by 30-70%, and its flexural strength by 39-91%. The improvement in flexural and splitting tensile strengths appeared more clearly. However, the results did not show any clear differences regarding the impact of either type of fiber (extracted and imported) meaning that the use of this fiber (from old tires) is more economical, in addition to being a solution to the problems caused by waste tires and a contribution in the protection of the environment and the society.