Avaliação das propriedades físico-mecânicas de argamassas reforçadas com fibras de poliéster de cabo de ancoragem de plataforma offshore

Abstract

The growing concern with sustainability has driven initiatives aimed at reducing the environmental impact caused by the production and disposal of waste, especially plastics, whose global generation has reached alarming levels. Among these wastes, anchoring cables used in offshore oil and natural gas platforms, installed in deep and ultra-deep waters, stand out. These cables, primarily composed of polyester fibers based on polyethylene terephthalate (PET), are discarded at the end of the decommissioning process of the facilities. Decommissioning is a mandatory phase that involves the safe removal of structures and equipment after the conclusion of exploration activities and requires the proper disposal of the materials used. Proper management of these wastes presents a strategic opportunity to promote a circular economy and reduce environmental impacts. In this context, the present study investigates the reuse of PET fibers from a new anchoring cable (new fibers) and a cable with 20 years of use (old fibers) as fibrous reinforcements in mortar with different volumetric fractions (0.25%, 0.50%, 0.75%, and 1.00%), evaluating consistency index, total water absorption, and uniaxial compressive and flexural tensile strengths. The results indicated that although both types of fibers affected the consistency of the fresh mix, cohesion was maintained in all mixtures, and molding was feasible using a vibrating table. Reinforcement with new fibers did not significantly alter water absorption or void index, but these properties increased with reinforcement using old fibers. Both types of fiber reinforcement caused significant reductions in specific mass, compressive, and flexural strengths. However, in both mechanical tests, for both fiber types, a shift from brittle behavior (reference) to ductile behavior (fibrous composites) was observed. The research shows the technical and environmental potential of incorporating PET fibers into cementitious materials, contributing to the reuse of industrial waste generated by offshore decommissioning. This approach reinforces the importance of sustainable solutions in civil construction and the management of highperformance plastic waste.