Avaliação do desempenho de concretos reforçados com fibras recicladas de PET e fibras de polipropileno

Abstract

The issue of PET (polyethylene terephthalate) accumulation has led to new research avenues for reuse in other sectors, such as the construction industry, where the material is already being utilized to produce formwork for casting and thermal-acoustic elements in walls and structural slabs. The addition of low modulus fibers to concrete offers various benefits, particularly in terms of toughness. These fibers increase toughness when added to concrete, resulting in increased ductility due to the residual strength transferred to the fiber after concrete cracking. Comparative aspects between PET and polypropylene fibers were analyzed through simplified Barcelona testing, axial compression testing, and parameters such as axial compression strength, tensile rupture modulus, and residual strengths for specified circumferential opening diameters of 2, 2.5, and 4 mm. Fibers were cut to a length of 30 mm for inclusion in concrete at percentages of 0.05, 0.1, and 0.2 by mass, and compared with polypropylene fibers at the same percentages. The addition of PET fibers can introduce new ways of utilizing the material. Through axial compression and simplified Barcelona testing, it was determined that PET fibers yield results similar to existing polypropylene fibers in the market, due to mechanical characteristics shared by both materials. The percentage of fiber addition impacted residual strength tests. For fixed TCOD values of 2, 2.5, and 4 mm, with PET and polypropylene fiber additions of 0.1 and 0.2%, it was concluded that fiber content affects residual strengths, while the material type has influence.