The Influence of Steel Fibers on the mechanical properties and thickness of precast concrete panels

Abstract

Concrete is well-known with its brittleness, low tensile strength and tensile strain capacities. This performance considered as one of the most crucial constraints that facing precast concrete industry. However, it could be improved by the addition of steel fibers which have been used widely in the last few decades. Hence, higher ductility and better arresting ability to crack propagation could be achieved. In Iraq, the precast concrete panels (flags) are commonly used for roofing and usually produced from plain concrete. This study aimed to add small volume fraction of steel fiber to the precast concrete panels to improve the handling and transportation process and assess their breaking load in according to the requirements of the Iraqi standard specification No.1107- 87. Concrete panels with (400×400mm) and different thicknesses (30 and 50mm) were produced. Different steel fiber volume fractions (0%, 0.25%, 0.5%, and 1%) were incorporated. The mechanical properties (compressive strength, splitting tensile strength, and flexural strength) for the concrete mixes were investigated. The test results of this study encourage the incorporation of small volume fraction of steel fiber in production of precast concrete panels to reduce the spoilage upon handling and transportation of precast concrete panels. The breaking load of steel fiber concrete panels has been improved by 142% relative to reference concrete panels. It was also revealed that the concrete panel thickness could be reduced when the steel fiber content increased, which could be of great interest with regards to the economic side. This is because of reducing the amount of raw materials used in production of concrete panels and thereby reducing the impact on the environment. The statistical analysis was accomplished by using the SPSS program.