عنوان مقاله [English]
Hardened concrete due to brittleness, have low tensile strength and its strain tolerance is low. Low resistance of this material makes it more brittle. Light weight concrete which contains eager and brittle materials are subject to sudden failure at the time of loading. In order to increase ductility and prevent the spread of micro-cracks as well as appropriate continuity in the concrete, increasing the energy absorption capacity, reducing the structural weight against shock loads, steel fibers can be useful. The purpose of this paper is evaluation of the influences of steel fiber on mechanical characteristic of concrete at the age of 7 and 28 days. Steel fibers used in forms of corrugated shape with length to diameter ratio of 37.5 and smooth-end hook shape with length to diameter ratio of 50. The volume percent in various forms is 1% constant. To calculate the mechanical properties of concrete we used tensile strength tests (Brazilian and direct), and compressive strength tests. The results indicate that they increase flexural strength, especially tensile strength of concrete, but they don’t have significant effect on the compressive strength.
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