Mechanical Properties of Different Concrete Ductile Materials

Abstract

This paper aimed to study the mechanical properties of brittle materials such as concrete as well as three different ductile materials. The ductile materials used were steel fibers reinforced concrete (SFRC), slurry infiltrated fiber concrete (SIFCON), and ultra-high performance fiber reinforced concrete (UHPFRC). Hooked-end steel fiber with a length of 30 mm and diameter of 0.5 mm (aspect ratio of 60) was used to reinforce ductile materials with volume fractions (V_f) of 1%, 1.5%, and 2% for SFRC and V_fof 1.5% and 7.5% for UHPFRC and SIFCON respectively. For this purpose, three cubes, four cylinders, and a prism for each material were cast and tested to investigate compressive strength, splitting tensile strength, modulus of rupture, modulus of elasticity, and stress-strain relationship under compressive stress. The experimental results showed that the failure mechanism for cubes, cylinders, and prism specimens of concrete changed from brittle to ductile failure by the presence of hooked-end steel fibers. Furthermore, increasing the V_f of steel fibers from (1 to 2) % improved the compressive strength, splitting tensile strength, modulus of rupture, and modulus of elasticity of concrete by (19.90-29.50) %, (90.59-141.40) %, (32.23-53.75) %, and (12.70-48.54) %, respectively, and increased the strain capacity of concrete at failure at least two times more than normal concrete without steel fibers. In addition, the compressive strength, splitting tensile strength, and flexural strength of UHPFRC increased by 132.67%, 293.95 %, and 237.43 %, respectively,  and for SIFCON increased by 146.06%, 503.15 %, and 615.77 %, respectively, as compared to normal concrete.