Effect of vibration time on some mechanical properties of high strength steel fiber reinforced concrete

ABSTRACT: Concrete is a widely used construction material which has a low tensile strength and a low strain capacity at fracture. To improve such ambiguities, reinforcement is used with reinforcing bars or steel fibers. While reinforcing steel bar is continuous and is particularly located in the structure to optimize performance, fibers are discontinuous and are generally distributed randomly throughout the concrete matrix. Based on previous researches, compaction of fresh concrete containing steel fibers is one of the most influential factors on mechanical properties. This study investigates effect of vibration time on mechanical properties of steel fiber reinforced concrete (SFRC). Considering the compressive strength above 55MPa, this study focuses on high strength concrete including three different percentages of steel fibers and control mix with no steel fiber tested that were vibrated at fresh state at four different vibration times. The compressive strength, flexural strength (load-deformation relations) and splitting tensile strength tests were performed on cubes, beams and cylinders and optimum vibration duration tried to be obtained for each property among all test results. …………………………………………………………………………………………………………………………………………………………………………………………………………