Experimental investigation of flexural behavior of beams made of fibrous concrete containing natural and recycled aggregates

Given that one of the most concrete and concrete construction materials with suitable compressive strength, ductility, tensile and flexural strength is low. For this purpose, in the past few years by adding fiber to fiber reinforced concrete and concrete construction, greatly improve the weaknesses. The purpose of this study is to investigate the effect of different fibers on the flexural behavior of reinforced concrete beams made with natural and recycled aggregates. In this research, 12 samples of reinforced concrete beams in two groups (6 beams made of natural aggregate and 6 beams made of recycled aggregate) were made in real scale with dimensions of 150×50×20 centimeters, which The reinforcement details of all the beams were the same and three types of steel fibers, polypropylene and Kortta were used separately and hybrid in the construction of the beams. Four-point flexural strength test was performed on the samples. Fracture mode, fracture behavior as well as absorbed energy parameters, ductility and final load capacity of beams made with natural and recycled aggregates were investigated. The results showed that the addition of hybrid fibers had a greater effect on improving the above parameters than separate fibers and also the flexural behavior of recycled samples with hybrid fibers could be closer to natural samples with separate fibers.