عنوان مقاله [English]
In this paper, the effect of HPFRCC with 1 and 2% of steel fibers on flexural behavior of two fixed-ends concrete beams was investigated. Four beams were cast and tested under concentrated load, two conventional beams and two HPFRCC beams (1 and 2% steel fibers) with two different stirrups spacing in the plastic zone. The average compressive strength is 55 MPa in HPFRCC beams and 50 MPa in conventional concrete beams, and the mixing design was considered so that the strengths of all samples were same. The type of loading was statically and in the middle of the span. Two fixed-end beams were arranged with a beam of 1.85 m in the middle and two rigid column of 0.3 m on the sides, which were connected to the frame by using 16 bolts of 22 mm to ascertain the rigidity of the problem, during the test, this rigidity was regularly controlled by the use of measures. The results of the experiments indicated that the use of 1 and 2% fibers in HPFRCC concrete increased the ductility and absorption of energy, As the displacement ductility increased by 54 and 100% in HC1 and HC2, while these numbers were 74 and 200 for energy ductility and also, the use of more fibers caused smaller cracks in concrete and improved its strength properties. By adding fiber, the length of the plastic hinge was increased 35% in HC1 and 47% in HC2.