Strength Performance of Hybrid Fiber-Reinforced Concrete Containing Manufactured Polypropylene and Ring- Shaped Polyethylene Terephthalate Waste Fibers

Fibers are basically utilized as substitutes for ordinary support in nonprimary applications to control early warm withdrawal and drying shrinkage breaking. However, polypropylene (PP), lamellar or straight fibers are weak interfacial bond strength of surface during fiber bridge stress. Therefore, to solve the limitations of traditional straight or irregularly PP fibers, ring-shaped poly-ethylene terephthalate fibers were promoted as combination fiber with manufactured PP fiber in concrete. This study aims to determine the slump flow, density, compressive strength, tensile strength and water absorption of hybrid fiber-reinforced concrete (FRC) containing manufactured PP and ring-shaped PET fiber. An experiment was conducted in fresh and mechanical properties of PP and ring-shaped PET fibers with the percentage of 0%, 0.5%, 1.0% and 1.5% for both fibers. The results of fresh FRC properties showed maximum values for mix control samples, while the minimum values for slump flow test was recorded with 1.5% of PP and 1.5% of ring-shaped PET which is 3.2% less than control sample. Meanwhile, density after 28 days curing was increased 5.8% than control samples with 0% of PP and 1.0% of ring-shaped PET. However, 1.0% of both PP and ring-shaped PET fibers achieved 6 and 22% increment for FRC compressive strength and splitting tensile strength, respectively. In conclusion, the fresh properties of concrete were decreased with incorporation of PP and ring-shaped PET fibers while hardened properties were improved.