An investigation on the behavior of two fixed end beams cast with HPFRCC composite

Abstract

In this paper, the effect of high-performance fiber reinforced cementious composite (HPFRCC) composite consisting of steel fibers on flexural behavior of two fixed-end concrete beams was investigated. Six beams including two reference and four beams with 1 % and 2 % steel fibers were cast and tested. The distance between stirrups in the plastic zone was considered as one variable. The mixing design was considered so that the compressive strengths of specimens to be close to each other. The type of loading was statically and in the middle of the span. Two fixed-end beams were arranged with a net span and two rigid columns on the sides connected to the frame by using bolts to prepare rigidity for supports. The results indicated that the ductility and absorption of energy of beams were increased up to 47 and 42 % by replacing conventional concrete by 1 % fibers HPFRCC and these amounts increased up to 66 and 85 % for beams with closed spacing stirrups in plastic zone and HPFRCC concrete, the ductility and absorption of energy of specimens cast with 2 % fibers HPFRCC were increased up to 76 and 174 % with 100 mm spacing stirrup and 89 % and 218 % were increased with 50 mm spacing stirrup in HPFRCC specimens. And also, the plastic lengths were increased up to 35 and 47 % by using of 1 and 2 % HPFRCC concrete, respectively. Moreover, the ultimate loads of specimens were increased from 52 to 76 % in concrete with 1 and 2% fibers. Therefore, the spaced stirrups and fiber percentage were effective on structural and performance parameters beams.