Comparison Between the Effects of Straight And Hook Steel Fibers on Fresh and Hardened Characteristics of Concrete

Abstract

This research looked into how steel fiber type and concentration influence Steel Fiber Reinforced Concrete (SFRC) mechanical properties. According to tests, the percentage of steel fibers in SFRC is directly related to compressive, flexural, splitting tensile, and direct tensile strength. Straight and hooked steel fibers with the same aspect ratio, 13 mm in length and 0.2 mm in width of straight steel fibers, and 35 mm long and 0.55 mm wide hook-end steel fibers were utilized. Three different percentages of fiber were used: 0.5, 1, and 1.5% by volume. Seven variants of concrete with different types and different percentages of steel fiber were created and evaluated. At 0.5, 1.0, and 1.5% fiber content, the compressive strength of a cube reinforced with hook steel fibers increased by 1.41, 11.52, and 20.81%, respectively, while the compressive strength of a cube reinforced with straight steel fibers increased by 7.27 and 20%, and 21.4% for the same percentages of steel hooked fiber. This indicates that the straight steel fibers are more effective than the hook steel fibers when increasing the compressive strength of the (SFRC). This means that (pressure force increases, albeit gradually). The concrete's splitting tensile strength may be significantly increased by introducing straight and hook steel fiber into the mixture. The tensile strength is improved by (52.78, 69.44, 122.22%) and (44.44, 62.8, 94.44%) when compared to the control concrete sample. Straight steel fibers increased flexural strength by (44.23, 61.54, 86.54%) compared to the control sample, and hook steel fibers increased flexural strength by (11.54, 28.85, 55.77%). When straight fibers are introduced to the control concrete sample, the direct tensile strength increases by about (54.17, 87.5, 162.5) %, and when hook fibers are added, the direct tensile strength increases by (45.83, 75, and 150%).